EL DORADO COUNTY · which in El Dorado County is the Community Development Agency, Environmental Management Division (CDAEMD). The SWRCB adopted the State OWTS Policy on June 19,

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EL DORADO COUNTY LOCAL AGENCY MANAGEMENT PLAN FOR ONSITE WASTEWATER TREATMENT SYSTEMS (LAMP) Effective as of May 13, 2018

Contents SECTION 1 - INTRODUCTION .............................................................................................................................. 1

A. BACKGROUND ........................................................................................................................................ 1

B. POLICY TIERS ........................................................................................................................................... 1

C. PROHIBITIONS ........................................................................................................................................ 3

D. EXISTING PARCELS .................................................................................................................................. 4

E. SEPTAGE CAPACITY ................................................................................................................................. 5

F. SEPTIC PUMPER TRUCK APPLICATIONS AND REGISTRATIONS ............................................................... 5

G. DATA COLLECTION/REPORTING/NOTIFICATIONS/RESPONSIBILITIES .................................................... 6

H. OWTS NEAR IMPAIRED WATER BODIES ............................................................................................... 11

I. ONSITE MAINTENANCE DISTRICTS ....................................................................................................... 12

J. REGIONAL SALT AND NUTRIENT MANAGEMENT PLANS ..................................................................... 12

K. WATERSHED MANAGEMENT GROUPS ................................................................................................. 12

L. PARCEL/LOT SIZE REQUIREMENTS ....................................................................................................... 12

M. HIGH DOMESTIC WELL USAGE AREAS .................................................................................................. 12

SECTION 2. OWTS PERMITTING PROCESS ....................................................................................................... 12

A. STATE, COUNTY, AND CITY ROLES State / County Coordination .......................................................... 13

B. SYSTEM DESIGN CONSIDERATIONS ...................................................................................................... 13

C. PERMITS ISSUED ................................................................................................................................... 15

D. CESSPOOLS ........................................................................................................................................... 15

E. RECREATIONAL VEHICLE HOLDING TANK WASTE ................................................................................ 15

F. STEPS IN THE PERMIT APPLICATION PROCESS ..................................................................................... 16

G. PERMIT APPLICATION REVIEW AND PERMIT ISSUANCE ...................................................................... 18

H. FINAL INSPECTION ................................................................................................................................ 18

I. PRIMARY AND REPLACEMENT AREA REQUIREMENTS ......................................................................... 19

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J. SEPTIC TANKS ....................................................................................................................................... 19

K. SUPPLEMENTAL TREATMENT AND ALTERNATE DISPERSAL OWTS ..................................................... 19

L. OWTS LEACH LINE DISPERSAL SYSTEMS ............................................................................................... 20

M. SETBACKS .............................................................................................................................................. 20

N. PROXIMITY TO PUBLIC SEWERS............................................................................................................ 20

SECTION 3. FAILING OWTS AND CORRECTIVE ACTION .................................................................................... 20

A. PROGRESSIVE FAILURE OF A LEACH FIELD ........................................................................................... 21

B. CORRECTIVE ACTION REQUIREMENTS ................................................................................................. 22

C. SUBSTANDARD SYSTEMS ...................................................................................................................... 24

SECTION 4. LAND DIVISIONS OF PARCELS SERVED BY OWTS ......................................................................... 24

SECTION 5. GROUNDWATER SEPARATION REQUIREMENTS FOR ONSITE WASTEWATER TREATMENT SYSTEMS AND OVERALL SOIL DEPTH DETERMINATIONS ................................................................................ 29

A. MINIMUM DEPTHS TO GROUNDWATER AND MINIMUM SOIL DEPTH FROM THE BOTTOM OF THE DISPERSAL SYSTEM ...................................................................................................................................... 29

B. SOIL PROFILE PITS ................................................................................................................................. 30

C. GROUNDWATER MONITORING ............................................................................................................ 30

D. PERCOLATION TEST PROCEDURE ......................................................................................................... 32

Appendices Appendix A. County of El Dorado – Regional Water Quality Control Board Jurisdiction (map) Appendix B. Tahoe Prohibitions - Excerpts from Porter-Cologne and Section 5.8 of the Lahontan Basin Plan Appendix C. Definitions.

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EL DORADO COUNTY LOCAL AGENCY MANAGEMENT PLAN FOR ONSITE WASTEWATER TREATMENT SYSTEMS SECTION 1 - INTRODUCTION A. BACKGROUND The California Water Code authorizes the State Water Resources Control Board (SWRCB) to regulate all discharges, including those from Onsite Wastewater Treatment Systems, which could adversely impact water quality. The policies of the SWRCB are implemented locally through nine (9) Regional Water Quality Control Boards. Historically, each regional board developed basin plans that outlined water quality objectives in their respective jurisdictions as well as policies and programs to achieve those objectives. Discharges are regulated through the use of Waste Discharge Requirements (WDRs). El Dorado County is under the jurisdiction of Region Five which is the Central Valley Regional Water Quality Control Board (RWQCB). The SWRCB regulatory authority extends to individual Onsite Wastewater Treatment Systems (OWTS). General guidelines for the siting, design, and construction of OWTS were part of each regional board's basin plans. The SWRCB and the regional boards recognize the advantages and efficiencies of OWTS regulation by local agencies. Consequently, while the regional boards retained primacy over large and specialized systems, direct regulatory authority for individual OWTS has been delegated to individual counties. The SWRCB Water Quality Control Policy for Siting, Design, Operation, and Maintenance of OWTS (State OWTS Policy) and Local Agency Management Plan (LAMP) are the culmination of the actions required by Assembly Bill 885 (AB 885). AB 885 was introduced to the California State Assembly on February 25, 1999, and would have impacted only coastal counties. The final version approved on September 27, 2000, was more inclusive, affecting all California counties. This legislation directed the SWRCB to develop regulations or standards for OWTS to be implemented statewide by qualified local agencies that issue OWTS permits, which in El Dorado County is the Community Development Agency, Environmental Management Division (CDAEMD). The SWRCB adopted the State OWTS Policy on June 19, 2012. The Policy was subsequently approved by the Office of Administrative Law on November, 13, 2012, and became effective on May 13, 2013. The State OWTS Policy allows local agencies to approve OWTS, based on a local ordinance, after submittal and approval of a LAMP by the applicable RWQCB. Under an approved LAMP, the requirement to obtain WDRs for an OWTS is conditionally waived for OWTS that are in conformance with the State OWTS Policy. Failure of counties to submit and obtain approval of a LAMP would mean that OWTS permits for only those few sites meeting the more restrictive Tier I requirements could be issued by local agencies. All other existing sites would potentially be subject to the WDR process.

B. POLICY TIERS

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The State OWTS Policy places OWTS in California into one of the following Tiers: TIER 0- Existing OWTS. These are defined as Existing OWTS that are properly functioning and do not meet the conditions of failing. These do not require corrective action as specifically described in Tier 4 and are not contributing to an impairment of surface water as specifically described in Tier 3. TIER 1 - Low-risk New or Replacement OWTS. These are New or Replacement OWTS that meet low risk siting and design requirements as specified in Tier 1. Minimum soil depths to groundwater and minimum soil depth from the bottom of a Dispersal System range from five (5) to twenty (20) feet based on soil percolation rates. TIER 2 - Local Agency Management Plan for New and Replacement OWTS. California is known for its extreme range of geological and climatic conditions. As such, the establishment of a single set of criteria for OWTS would either be too restrictive so as to protect the most sensitive case or would have broad allowances that would not be protective enough under some circumstances. To accommodate this extreme variance, local agencies may submit management programs known as the Local Agency Management Plan (LAMP) for approval by the RWQCB, and then upon approval, manage the installation of New and Replacement OWTS under that plan. An approved LAMP allows local agencies to develop customized management programs that address the soil and groundwater depths specific to that jurisdiction. The LAMP must be approved by the appropriate RWQCB. Under an approved LAMP, separation of the bottom of a Dispersal System to groundwater of as little as two (2) feet may be allowed with an approved Alternate Dispersal System OWTS (also known as a Special Design OWTS in El Dorado County). Once approved, the standards contained in an approved LAMP supersede the Tier 1 standards. However, systems meeting Tier 1 soil and siting criteria would be considered a Standard OWTS within El Dorado County. TIER 3 - Impaired Areas. Systems that are within six hundred (600) feet of impaired water bodies as defined in Section 303(d) of the federal Clean Water Act. There are no such water bodies identified within El Dorado County. TIER 4 - OWTS Requiring Corrective Action. OWTS that require corrective action or fail at any time while this LAMP is in effect are automatically in Tier 4 and must follow Tier 2 requirements pending completion of corrective action. It is El Dorado County's intent to regulate projected wastewater flows up to 10,000 gallons per day under Tier 2 for dispersal underground only. In addition to projects that may have waste strength greater than normally found in domestic flows evaluated by CDAEMD staff, any project with a projected flow nearing 10,000 gallons per day will be discussed with the RWQCB staff. Additionally, through the use of a variety of Supplemental Treatment Systems and/or Alternate Dispersal Systems, which are described in the Standards for the Site Evaluation, Design, and Construction of Onsite Wastewater Treatment Systems (OWTS Manual), this LAMP includes a number of differing system designs

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and monitoring requirements to meet the full intent of the State OWTS Policy. The Director of the CDAEMD shall maintain the OWTS Manual and may amend the OWTS Manual to reflect current engineering concepts and legal requirements only upon a written finding that the amendment is consistent with the LAMP and the State OWTS Policy. CDAEMD is committed to protecting public health and water quality while allowing continued development in El Dorado County. C. PROHIBITIONS (OWTS Policy 9.4) (OWTS Manual Section 1H)

1. Pursuant to the State OWTS Policy, the following are not authorized in the CDAEMD LAMP: • Cesspools of any kind or size. (OWTS Policy 9.4.1) • OWTS receiving a projected flow over 10,000 gallons per day. (OWTS Policy 9.4.2) • OWTS that utilize any form of Effluent dispersal that discharges on or above the post

installation ground surface such as sprinklers, exposed drip lines, free-surface wetlands, a pond, or any other similar surface discharge. (OWTS Policy 9.4.3)

• Slopes greater than 30 % without a slope stability report approved by a Qualified Professional. (OWTS Policy 9.4.4)

• Decreased leaching area for International Association of Plumbing and Mechanical Officials (IAPMO) certified Dispersal Systems using a multiplier less than 0.70. (OWTS Policy 9.4.5)

• OWTS utilizing Supplemental Treatment without requirements for periodic monitoring or inspections. (OWTS Policy 9.4.6)

• OWTS dedicated to receiving significant amounts of wastes dumped from Recreational Vehicle (RV) holding tanks. (OWTS Policy 9.4.7)

• Separation of the bottom of Dispersal System to groundwater less than two (2) feet. (OWTS Policy 9.4.8)

• Installation of New or Replacement OWTS where public sewer is available. The public sewer may be considered unavailable when such public sewer or any building or exterior drainage facility is located more than two hundred (200) feet from any proposed building or exterior drainage facility on any lot or premises that abuts and is served by such public sewer. This provision does not apply to Replacement OWTS where the connection fees and construction costs are greater than twice the total cost of the Replacement OWTS and the CDAEMD determines that the discharge from the OWTS will not affect groundwater or surface water to a degree that makes it unfit for drinking or other uses. (OWTS Policy 9.4.9)

• California State Water Code (Porter-Cologne Water Act) Chapter 12 (Cal. Health & Safety Code, §§ 13950-13952.5), prohibits the disposal of municipal wastewater to groundwater and requires export of sewage from the Tahoe Basin, therefore OWTS will not be permitted. Any previously unknown OWTS, once discovered, will be identified and CDAEMD will consult with appropriate RWQCB staff to evaluate options for sewage disposal (Appendix A. County of El Dorado – Regional Water Quality Control Board Jurisdiction [map] and Appendix B. Tahoe Prohibitions) (OWTS Policy 9.1.2).

2. Horizontal Setback Requirements (OWTS Policy 9.4.10) (OWTS Manual Section 2B). Except as provided in the noted exceptions below, CDAEMD may not approve New or Replacement OWTS with the minimum horizontal setbacks less than any of the following:

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• One hundred fifty (150) feet from a Public Water Well where the depth of the effluent Dispersal System does not exceed ten (10) feet in depth. (OWTS Policy 9.4.10.1)

• Two hundred (200) feet from a Public Water Well where the depth of the effluent Dispersal System exceeds ten (10) feet in depth. (OWTS Policy 9.4.10.2)

• Where the effluent Dispersal System is within six hundred (600) feet of a Public Water Well and exceeds twenty (20) feet in depth, the horizontal setback required to achieve a two-year travel time for microbiological contaminants shall be evaluated. A Qualified Professional shall conduct this evaluation; however, in no case shall the setback be less than two hundred (200) feet. (OWTS Policy 9.4.10.3)

• Where the effluent Dispersal System is within twelve hundred (1,200) feet from a Public Water System’s surface water intake point, within the catchment of the drainage, and located such that it may impact water quality at the intake point such as upstream of the intake point for flowing water bodies, the Dispersal System shall be no less than four hundred (400) feet from the high water mark of the reservoir, lake, or flowing water body. (OWTS Policy 9.4.10.4)

• Where the effluent Dispersal System is located more than twelve hundred (1,200) feet but less than twenty-five hundred (2,500) feet from a Public Water System's surface water intake point, within the catchment area of drainage, and located such that it may impact water quality at the intake point such as upstream of the intake point for flowing water bodies, the Dispersal System shall be no less than two hundred (200) feet from the high water mark of the reservoir, lake, or flowing water body. (OWTS Policy 9.4.10.5)

3. Exceptions • For Replacement OWTS that do not meet these horizontal separation requirements, the

Replacement OWTS shall meet the horizontal separation to the greatest extent practicable. In such cases, the Replacement OWTS shall utilize Supplemental Treatment and other mitigation measures, unless the CDAEMD finds that there is no indication that the previous system is adversely affecting the public water source and there is limited potential that the replacement system could impact the water source based on topography, soil depth, soil texture, and groundwater separation. (OWTS Policy 9.4.11)

• For New OWTS, installed on parcels of record at the time of effective date of this LAMP, that cannot meet the above horizontal separation requirements, the OWTS shall meet the horizontal separation to the greatest extent practicable and shall utilize Supplemental Treatment for pathogen reduction and any other mitigation measures prescribed by the CDAEMD. (OWTS Policy 9.4.12)

D. EXISTING PARCELS (OWTS Policy 9.1.11) (OWTS Policy 9.1.12) (OWTS Policy 9.2.3) (OWTS Manual Section 1)

There are thousands of existing parcels within El Dorado County that have been developed using OWTS for sewage disposal/treatment purposes. CDAEMD is aware that many Existing OWTS may now be considered substandard as a result of their development prior to the adoption and implementation of current or historical El Dorado County Sewage Disposal Standards (under standards less stringent than those required by the State OWTS Policy). Those systems may be on small lots. The OWTS serving these parcels will be carefully evaluated either under our complaint report program, when the system is evaluated after

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receipt of a repair/replacement permit application, or as part of a request to further develop the parcel(s). The intent of CDAEMD is to allow the continued use or uses on the parcel while bringing the OWTS serving the parcel into compliance with the State OWTS Policy to the greatest extent practicable. The many existing undeveloped parcels in the County will be evaluated under this LAMP for compliance with the horizontal setback requirements to the greatest extent practicable. The minimum two-foot vertical separation between the bottom of the trench and groundwater, required by the State OWTS Policy, cannot be waived through the County's LAMP. Many existing undeveloped parcels were created with percolation rates over 120 minutes per inch (MPI). Those parcels that show percolation rates between 120 and 240 minutes per inch will be required to mitigate the condition with Special Design OWTS with subsurface drip dispersal, mounds, shallow pressure distribution trenches (with rock or sand), and At-Grade Systems. The Special Design OWTS will be dependent on soil depth, slope, and other conditions in order to protect the waters of the State and public health. These parcels will be closely evaluated to allow the development of the parcel while bringing the OWTS for the parcel into compliance with the State OWTS Policy to the greatest extent practicable. Supplemental Treatment systems will require annual permits with specific monitoring requirements and an annual inspection will be performed by the Service Provider.

E. SEPTAGE CAPACITY (OWTS Policy 9.2.6) (County Ordinance 8.06) Septage is the term used for the partially treated solid and liquid material removed from septic tanks, from some treatment systems by septic tank pumper trucks (also known as liquid waste haulers). This material includes settled solids, other floating materials, and some amount of liquid. The solid material must be removed from Septic Tanks to prevent the tank from filling up and potentially damaging the Dispersal System or any Supplemental Treatment system that may be in use. Removal frequency is different for each system, based on tank capacity and use, but generally is not less than every three (3) years. CDAEMD intends to regulate all OWTS not prohibited by the State OWTS Policy and will seek enforcement action against all OWTS that are prohibited by the State OWTS Policy. Some wastes may be considered high-strength wastewater, which is too “strong” or concentrated for discharge into an OWTS. For example, concentrated wastewater discharged from RV holding tanks, which has resulted in numerous failing OWTS and are more appropriate for storage in holding tanks and removal and transport by septage pumpers to the Union Mine Waste Water Treatment Facility (WWTF). The treatment portion of the WWTF is designed to treat approximately eight (8) million gallons of leachate, septage and portable toilet waste annually, or approximately 22,000 gallons per day (gpd). The WWTF is permitted to treat 16,000 gpd under the current WDR. F. SEPTIC PUMPER TRUCK APPLICATIONS AND REGISTRATIONS (OWTS Policy 3.3.2)

(County Ordinance 8.06) CDAEMD requires applications from, issues permits to operate to, and inspects all permitted septage pumper trucks annually within El Dorado County. Inspections of pumper trucks by CDAEMD primarily focus on health, sanitation, and safety issues relating to the trucks, equipment, and employees.

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Pumper/haulers are required to report all septic tanks that they pump in the County on a monthly basis. CDAEMD reviews and logs pumping reports into a database to determine if excessive pumping is taking place of an OWTS and will investigate to determine if there is a potential failure of the OWTS. G. DATA COLLECTION/REPORTING/NOTIFICATIONS/RESPONSIBILITIES (OWTS

Policy 9.3) (OWTS Policy 9.3.1) (OWTS Policy 3.3.1) As a condition of CDAEMD oversight of OWTS within El Dorado County, CDAEMD has certain responsibilities related to data collection and reporting to the RWQCB. CDAEMD also submits data collected from owners and operators of Public Water Systems to the State Water Resources Control Board's Division of Drinking Water (SWRCB-DDW). This Section details data that must be collected by CDAEMD, the procedures for reporting to the RWQCB, and notifications to owners of Public Water Systems and the SWRCB-DDW.

1. Water Quality Assessment Program (OWTS Policy 9.3.2) (OWTS Policy 9.3.2.1) (OWTS Policy 9.3.2.2) (OWTS Policy 9.3.2.3) (OWTS Policy 9.3.2.4) (OWTS Policy 9.3.2.5) (OWTS Policy 9.3.2.6) (OWTS Policy 9.3.2.7) (OWTS Policy 9.3.2.8) (OWTS Policy 9.3.2.9) CDAEMD will maintain a water quality assessment program to determine the general operational status of Existing OWTS and those systems permitted under this LAMP. CDAEMD will evaluate the impact of discharges from OWTS and assess the extent to which groundwater, local surface water may be impacted. This program will primarily focus on areas where there are shallow or poorly drained soils, fractured Bedrock, shallow Groundwater, proximity to surface water, individual OWTS or a high concentration of OWTS that predate this LAMP, and a high concentration of domestic water wells. Data collected for this program will include the results of investigations into complaints of failing OWTS, inspections of operating OWTS by CDAEMD staff and Service Providers, sample results from our Local Primacy Agency program, which regulates small Public Water Systems, sample results submitted from local watershed management groups, and any other water samples of surface or ground water reported to or obtained by CDAEMD staff including those data collected during well inspections, from monitoring wells, data from GeoTracker, GAMA, parcel maps for subdivision development, from state agency permitted facilities, and other sources of reliable information. The monitoring program may identify areas requiring additional scrutiny of soil test results and designs for proposed OWTS including those OWTS that are new, repaired, replaced, and increased in capacity. The monitoring program may also identify the need for more frequent inspections or maintenance of OWTS.

2. Records Retention (OWTS Policy 3.4)

At a minimum, CDAEMD will retain permanent records of permitting actions and will make them available to RWQCB staff within ten (10) working days upon written request for review. The records for each permit shall reference under which Tier (1, 2, or 4) the permit was issued. CDAEMD uses a computer database to track permits for all projects issued by the CDAEMD including future OWTS permits. Paper copies of completed system applications, soil test data, final drawings, and other related documents are filed in the CDAEMD office until the OWTS has been granted final approval at which time these documents are scanned into a database.

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3. Reporting to the RWQCB (OWTS Policy 3.3 and Policies 3.3.1 through 3.3.3) (OWTS Policies 9.3.2 and 9.3.3)

a. An annual report will be submitted to the RWQCB by February 1st each year, in a format prescribed by the State OWTS Policy and with the following information: (1) The number and location of complaints pertaining to OWTS operation and maintenance

and identification of those which were investigated and how they were resolved. (OWTS Policy 3.3.1)

(2) The number, location, and description of permits issued for new and Replacement OWTS and under which Tier the permit was issued, noting any variance allowed for systems otherwise in substantial conformance with the standards. (OWTS Policy 3.3.3)

(3) The applications and registrations issued for sewage haulers as part of the septic tank pumper program. (OWTS Policy 3.3.2)

(4) Results of the Water Quality Assessment Program intended to evaluate the impact of OWTS on local surface water and groundwater. Any groundwater monitoring data collected shall be submitted in Electronic Deliverable Format (EDF) format for inclusion into GeoTracker, the SWRCB’s database of which this data will have exclusive view by RWQCB staff. At this time, at a minimum, it is expected that groundwater monitoring will include, but not be limited to, any samples collected from small Public Water Systems regulated by CDAEMD and any other samples collected in response to subdivision and parcel map developments, complaints, and samples that may be required from OWTS monitoring wells. Surface water monitoring shall be submitted to the California Environmental Data Exchange Network (CEDEN) in a Surface Water Ambient Monitoring Program (SWAMP) comparable format. (OWTS Policies 9.3.2 and 9.3.3)

b. Every five (5) years, an evaluation of the monitoring program and an assessment of whether

water quality is being impacted by OWTS within El Dorado County will be completed. The evaluation prepared by CDAEMD for the RWQCB will identify any changes to the LAMP, if applicable, required to address any impacts from OWTS. (OWTS Policy 9.3.3)

4. Reporting to Owners of Public Water Systems and Division of Drinking Water at the

SWRCB (OWTS Policy 3.5) (OWTS Policy 9.2.11) (OWTS Policy 9.2.12) (OWTS Manual Section 4H) CDAEMD shall notify the owner of a public well or water intake and the SWRCB-DDW as soon as is practicable, but not later than seventy-two (72) hours, upon verification of a major failure of an OWTS component within:

• One hundred fifty (150) feet of a Public Water Well; and • Within twenty-five hundred (2,500) feet from a Public Water System surface water intake.

Additionally, CDAEMD will notify the Public Water System prior to the issuance of a new installation or repair permit for an OWTS if a surface water intake is within twelve hundred (1,200) feet of a proposed OWTS, is within the drainage catchment of the intake point and is located such that it may impact water quality at the intake point, or if the proposed OWTS is within the horizontal sanitary setback from a public well. Notification is to be made by CDAEMD upon receipt

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of an application for a new or repair permit and prior to issuance of the permit. Notifications will be in email format and emailed to the water system or when email is not available, hard copies will be sent using U.S. Mail. The Public Water System owner shall have fifteen (15) days from receipt of the permit application to provide recommendations and comments to the permitting agency. For OWTS permit applications for Dispersal Systems within the horizontal sanitary setback of a public well or a surface water intake point, CDAEMD shall first work with the owner of the proposed OWTS to see if relocation of the Dispersal System is possible. Per the State OWTS Policy, an OWTS with Supplemental Treatment for nitrogen reduction and Supplemental Treatment for pathogen reduction may be required if the Dispersal System cannot be relocated to meet the required setback.

5. Outreach Program (OWTS Policy 9.2.5) CDAEMD has copies of sewage disposal standards, percolation test instructions, data sheets, and other related documents available to the public in the CDAEMD office and on the County website. All new materials will be available when applicable. With few exceptions, documents in CDAEMD files are public records. These include copies of OWTS documents such as permitting and installation records, site location drawings, soil test data, copies of applications for permits to drill wells, copies of Public Water System sample results, soil test results conducted as part of a proposed land division, and other records that may relate to OWTS. Upon request, CDAEMD staff can provide presentations to local homeowner or industry groups or organizations regarding OWTS standards, use, operation, design, construction, and maintenance. CDAEMD generally has information booths at local events, including Earth Day events, the local Home and Garden Show, Household Hazardous Waste collection events, and the El Dorado County Fair. In addition to OWTS construction permits, CDAEMD will be issuing operating permits for OWTS constructed at sites with soils that do not meet the minimum Tier 1 requirements, including Supplemental Treatment OWTS or other Special Design OWTS as determined by CDAEMD. These permits will require notification, within time frames specified, of any failure or upset conditions with the permitted system. Additionally, CDAEMD will require that an operations and maintenance plan is prepared for each system by the Qualified Professional designing the system. This document shall be provided to the property owner and will include (as will the CDAEMD issued operating permit) procedures to ensure maintenance, repair, or replacement of failing critical items within forty eight (48) hours following discovery. To assist OWTS owners in providing proper maintenance and repairs to their system, and in reporting upset conditions, CDAEMD will maintain a list of Service Providers and Qualified Professionals on the County website, including those contacts that are available twenty-four (24) hours a day, seven (7) days a week, if they exist.

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Should CDAEMD implement a voluntary well monitoring program in the future, the outreach program will include information on how well owners may participate.

6. CDAEMD Responsibility (OWTS Policies 9.3 and 9.3.1)

Permits issued for the construction of a new or Replacement OWTS requiring an Operation and Maintenance (O&M) Plan shall be prepared for the OWTS owner by a Qualified Professional. This Plan will detail operating procedures and maintenance requirements and frequencies. CDAEMD will establish and maintain a record keeping and reporting system to ensure that current records are kept detailing the location, ownership, site evaluation, design, and O&M reports so that the performance of the systems approved under Tier 2 can be monitored. CDAEMD will monitor and analyze the performance of OWTS within the County by reviewing O&M data. CDAEMD will assure timely follow-up and correction, including enforcement action when necessary, when problems are encountered with treatment or dispersal technologies which are being monitored through the O&M program. CDAEMD may perform O&M inspections, as needed, for quality assurance/quality control, surveys, and investigations.

7. Property Owner, Qualified Professional, and Service Provider Responsibility

Property owners, Qualified Professionals (consultants/designers), and Service Providers (system operators and maintenance technicians) all have responsibilities with respect to the use, operation, maintenance, inspection, and reporting related to all OWTS permitted in El Dorado County. The failure of one of these team members to abide by their respective responsibilities may result in premature upset or failure of the OWTS. Failure of an OWTS can lead to surface water or groundwater contamination with untreated or partially treated wastewater and potential public health hazards. Another result of a failing OWTS is the expense to repair or replace the system. This can be equal to, or more than, the construction cost of the original system. a. Property Owner

Every OWTS requires care with use and timely maintenance to continue to function as they are designed to function. An OWTS is sized for an expected use. A number of OWTS have failed due to misuse or use beyond that expected when the system was designed and constructed. Using the system beyond its design flows will lead to premature failure. Using the system to dispose of large quantities of household cleansers or disposal of a wastewater stream different from that which the system was designed for can significantly reduce the life span and effectiveness of the OWTS. El Dorado County has multiple options for disposal of Household Hazardous Waste, including curbside pickup and free drop off at permanent collection facilities. Pickup information is available on the County website and provided at County-sponsored HHW events. A property owner must be accurate with the proposed use, quantity, and wastewater stream, when discussing the proposed OWTS with their Qualified Professional and with CDAEMD.

All OWTS require maintenance. This can be as simple as having the septic tank inspected and pumped on a regular basis to the necessary more thorough inspection and maintenance of Supplemental Treatment systems. Generally, most permits issued under this LAMP include at

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least some inspection, maintenance, monitoring, and reporting requirements within specified timeframes depending on the complexity of the system installed. An owner of an OWTS must adhere to these tasks at their specified timeframes to assist in keeping their OWTS operating as designed. Owners must contract with a qualified Service Provider, familiar with the type of OWTS in use, to conduct the inspections, maintenance, monitoring, and reporting, as required by the specified timeframes, through a valid installation/operating permit. An owner must correct deficiencies in the OWTS that have been identified by CDAEMD and/or a Service Provider or Qualified Professional.

CDAEMD does not currently regulate the construction and use of gray water systems. These systems are permitted by El Dorado County Community Development Agency Development Services Division (CDADSD) under a plumbing permit. CDADSD will consult with CDAEMD as necessary. An OWTS is designed for a specified wastewater strength and quantity. Property owners should be aware that the use of a gray water system may have an impact on an OWTS in use at a site. OWTS owners need to be sure that the Qualified Professional and CDAEMD staff are aware that a gray water system may be constructed, or consider a Supplemental Treatment system, such as a drip dispersal system, allowing OWTS liquid waste to assist in watering vegetation at the site. CDAEMD does not allow a reduction in the size of an OWTS when a gray water system is proposed at a site.

b. Qualified Professional (OWTS Policy 9.1.7) (OWTS Policy 9.1.10) (OWTS Policy 9.2.4) (County

Ordinance 110.32.130) Every new/proposed OWTS, and most onsite system repairs, must be designed by a Qualified Professional (see definitions in Appendix A). Qualified Professionals will test each site, recommend a system for the site based on test results, site soil and groundwater depths, and design and provide specifications for that system. The Qualified Professional must be certain that the system is being designed for the proper wastewater strength and flow. The Qualified Professional must consider potential pathways of wastewater-sourced phosphate and other nutrients toward potentially threatened nearby surface water bodies, when present. They will also consider hydraulic mounding, nitrate and pathogen loading, and sufficiency of potential OWTS replacement areas. The OWTS, potential replacement areas, and all proposed site improvements and structures must fit onto existing and proposed parcels while meeting or exceeding all appropriate setbacks and would be verified by the Qualified Professional on the site plan. The Qualified Professional must work with the installer to ensure that the system, as constructed, meets the specifications of their design and the permit issued by CDAEMD. An accurate as-built site plan, showing the system location, must be prepared and provided to the property owner.

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An operation and maintenance plan prepared by the Qualified Professional or system manufacturer, and made available to the system owner, is required of every Alternate Dispersal or Supplemental Treatment system installed on parcels in El Dorado County. Proper use and routine maintenance at specified intervals, as directed by CDAEMD in a valid OWTS operating permit, is necessary in order for an OWTS to function as designed for as long as possible. The OWTS designer (Qualified Professional) shall prepare the following operations and maintenance plan that is amended if the system is upgraded or requires repair and includes:

• An accurate scale drawing showing the actual location of the OWTS installed on a parcel for

ease in locating the system for inspections, maintenance, and monitoring. The drawing is to include the location of all system components;

• An O&M manual specific to the type of system installed. It shall contain a narrative describing how the system achieves its treatment standards/goals. The manual shall note homeowner or Service Provider procedures to ensure maintenance for continued operation, repair, or replacement within forty-eight (48) hours of identifying a failing system. The manual is to detail the type of maintenance or monitoring required and when these tasks should be done;

• The tasks can be performed by an owner or if a Service Provider is the more appropriate choice to perform them;

• The names and telephone numbers of the Qualified Professional, licensed system installer, and OWTS Service Provider; and

• The reporting required to CDAEMD as a result of these inspections, monitoring, and maintenance or actual failure conditions;

c. Service Provider (OWTS Policy 9.2.4) (OWTS Manual Section 2D)

The property owner must contract with a Service Provider to provide necessary inspection, maintenance, monitoring, and reporting services as specified in a valid OWTS permit as issued by CDAEMD. Most OWTS owners may not understand how a system functions and recognize signs that the system needs maintenance or is failing. It is extremely important that the Service Provider complete the required tasks to keep the system operating as planned. When required by providers of proprietary equipment, the Service Provider must meet and maintain the requirements for qualification for the specific proprietary equipment. The Service Provider shall provide all maintenance records to the property owner and report any system malfunction that results in surfacing sewage to the owner and CDAEMD within 48 hours.

H. OWTS NEAR IMPAIRED WATER BODIES (OWTS Policy 9.1.8) (OWTS Policy 9.2.2) None of the impaired water bodies listed in Attachment 2 of the State OWTS Policy are in El Dorado County. CDAEMD will follow the applicable specific requirements of the State OWTS Policy should a water body within El Dorado County be added to the State’s list.

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I. ONSITE MAINTENANCE DISTRICTS (OWTS Policy 9.2.7) Currently there are two (2) onsite maintenance districts or zones within El Dorado County, Greenstone Estates and Auburn Lake Trails. These systems are regulated by the state RWQCB and CDAEMD. CDAEMD keeps records on these facilities and conducts inspections. J. REGIONAL SALT AND NUTRIENT MANAGEMENT PLANS (OWTS Policy 9.2.8) There are no existing regional salt or nutrient management plans within El Dorado County nor are any anticipated in the foreseeable future. K. WATERSHED MANAGEMENT GROUPS (OWTS Policy 9.2.9) Currently, CDAEMD has no formal agreements with any watershed management groups within El Dorado County. Coordination with volunteer groups or any watershed management groups will be evaluated. L. PARCEL/LOT SIZE REQUIREMENTS (OWTS Policy 9.1.2) (OWTS Policy 9.1.10) (OWTS Manual

Section 1D) It should be noted that there has not historically been a minimum lot size for existing lots to be served by an OWTS (that are not also served by a well on the same parcel) and many small parcels have been created over the years, some of which have yet to be developed. However, the OWTS, including the 100% replacement area, shall meet all applicable setbacks to all proposed structures which include, but are not limited to, dwellings, wells, pools, barns, shops, garages, driveways, and other graded/paved/concrete areas which shall fit on the property without interfering with the OWTS unless an exception is provided for under this LAMP. Section 4 of this LAMP provides specific requirements regarding the creation of new parcels (land divisions) served by OWTS within El Dorado County. Minimum parcel sizes are required by land use agencies per specific site zoning for the County and City of Placerville. M. HIGH DOMESTIC WELL USAGE AREAS (OWTS Policy 9.1.4) (OWTS Policy 9.1.9) (OWTS Policy

9.1.11) (OWTS Policy 9.1.12) (Proposed Well Ordinance) A majority of El Dorado County residents are served by public or privately operated water systems. Well drilling has been limited to parcels greater than or equal to four and one-half (4.5) acres since 1977 and greater than or equal to five (5) acres since the adoption of the 2004 General Plan. Most existing subdivisions with smaller lots are supplied with public water from El Dorado Irrigation District, City of Placerville, Grizzly Flats and Georgetown Divide Public Utilities Districts, or several other small Public Water Systems. CDAEMD staff is not aware of any nitrogen impacts to groundwater as a result of the OWTS density in these areas. There are many areas of El Dorado County developed on wells and OWTS but the density is not high enough to be defined as high Domestic Well usage areas.

SECTION 2. OWTS PERMITTING PROCESS (OWTS Policy 9.2.1) (OWTS Manual Sections 1 and 4)

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A. STATE, COUNTY, AND CITY ROLES State / County Coordination OWTS discharge pollutants to groundwater and, therefore, are regulated by the State Water Code. Water Code Section 13282 allows the RWQCBs to authorize a local public agency to issue permits for and to regulate OWTS, "to ensure that systems are adequately designed, located, sized, spaced, constructed, and maintained." The RWQCB with jurisdiction over El Dorado County authorizes only the CDAEMD to issue certain OWTS permits throughout the County, including within the City of Placerville, when necessary. Through the State OWTS Policy, the RWQCB has imposed conditions and restrictions on the County's permit program. CDAEMD is authorized to issue permits for Standard OWTS and Special Design OWTS with or without Supplemental Treatment within the County. The Adopted State OWTS Policy requires a minimum of five (5) feet and up to twenty (20) feet of separation maintained between the bottom of a Dispersal System point and the highest anticipated groundwater level for Standard OWTS, and at least two (2) feet of separation for some Alternate Dispersal Systems, including some with Supplemental Treatment. The goal of the CDAEMD LAMP is to ensure that installed OWTS will last the life of any structure they serve and not cause any public exposure to surfacing sewage or potential contamination of groundwater or surface waters. The separation requirements are a condition of the State's authorization for El Dorado County to issue OWTS permits locally. The CDAEMD OWTS Manual describes in detail how the County ensures that these State-imposed separation requirements are determined and satisfied. CDAEMD is a fundamental part of the County’s land use approval and permitting processes. While they are coordinated to a great extent, persons seeking OWTS permits from CDAEMD should also review and ensure compliance with applicable site grading, land use, and building requirements. Similarly, no local land use approval or permit, including, but not limited to, approved land divisions, property line adjustments, or use permits, is a substitute for a County OWTS permit, or a guarantee that such a permit will be issued. B. SYSTEM DESIGN CONSIDERATIONS (OWTS Policy 9.1.3 and 9.1.6) (County Ordinance

110.32.130) (OWTS Manual Sections 1 and Section 2) The most common type of Standard OWTS found in El Dorado County consists of a septic tank connected to leach lines. In all cases, the majority of solids, fats, oil, and grease are removed in the septic tank and Effluent from the septic tank is discharged below the ground surface. Organic material present in this Effluent is digested by bacteria in unsaturated soil zones underground. These systems are designed to operate in all weather conditions with minimal maintenance, other than periodic septic tank pumping to remove accumulated sludge and floating scum that form in the septic tank. Under this LAMP, sites with Tier 1 minimum of five (5) to twenty (20) feet of soil beneath a Dispersal System trench, based on soil percolation rates, would not require mitigation or monitoring and a septic tank and leach line Dispersal System could be constructed under a valid OWTS Permit.

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In addition to Standard OWTS, El Dorado County allows the use of Special Design OWTS. These systems are generally used for those sites that cannot support the use of a Standard OWTS due to shallow ground water, soil permeability, slope, or soil depth. A variety of OWTS mitigations were accepted in the past to deal with these specific site conditions including shallow trenches, pumps, Curtain Drains, dual leach fields, and other alternative systems and these were designated as Special Design OWTS. The approved State OWTS State Policy now sets a minimum soil depth and separation from groundwater at two (2) feet with the use of a Supplemental Treatment and/or Dispersal System to treat septic tank Effluent prior to discharge into the soil. CDAEMD may allow the use of other systems not otherwise prohibited by the State OWTS Policy. The size and type of OWTS necessary for a residence or other use will nearly always be a function of the following factors:

1. Soil Permeability. Permeability determines the degree to which soil can accept septic tank or Supplemental Treatment system Effluent over a period of time. Permeability is determined by a percolation test and is reported as a percolation rate, in minutes per inch. (OWTS Policy 9.1.6)

2. Unsaturated Soil Interval. The distance between the bottom of the OWTS dispersal field and the highest anticipated groundwater level or the impervious subsurface layer at the site. (OWTS Policy 9.1.3)

3. Peak Daily Flow. The anticipated peak sewage flow in gallons per day. In most cases the number of bedrooms for a proposed home is used as an indicator of peak daily flow. Daily flow in non-residential uses is calculated from expected flows from charts in the Uniform Plumbing Code, adopted by El Dorado County, and other similar charts or actual flows of similar projects acceptable to CDAEMD.

4. Net Useable Land Area. The area available that meets all setback requirements from structures, easements, watercourses, or other geologic limiting factors for the design/placement of an OWTS. A site may not be developed beyond its capacity to properly treat and disperse the amount of liquid waste expected/generated.

5. Wastewater Strength. Wastewater strength has been of some importance with non-residential systems such as restaurants or other commercial or industrial systems. This is because there may be less water in the waste stream or more solid material, oils, fats, grease, or cleansing or sanitizing materials may be present when compared to what is expected in residential wastewater. Wastewater strength with residential systems may be more important in the future as gray water systems divert a large part of the liquid component of residential wastewater flow from the septic tank.

Some sites may not be acceptable for Standard or Special Design OWTS based on high or low soil permeability and net useable area, regardless of the unsaturated soil interval available at the site. All Standard OWTS in El Dorado County will require minimum of five (5) feet between the bottom of the dispersal system and the highest anticipated groundwater level for the site. A Special Design OWTS will require a minimum of two (2) feet separation. Depth to groundwater varies tremendously with the

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amount of precipitation and soil types for specific sites and areas within El Dorado County, therefore, the highest anticipated groundwater level must be established for any OWTS design in order to meet this separation requirement. Details in determining depth to groundwater and overall soil depth are provided in Section 5 of this LAMP. The net useable land area required for an OWTS will usually depend on soil permeability, soil depth, expected peak daily flows, and the required 100 % Dispersal System replacement area. C. PERMITS ISSUED (OWTS Policy 3.3.3, 9.1.1 and 9.2.12) (OWTS Manual Section 2D) Under the CDAEMD OWTS Manual, new systems are considered Standard or Special Design OWTS. Special Design OWTS are systems that require some mitigation for sites that did not meet the minimum standards. CDAEMD will continue to require the Special Design OWTS as specified in the CDAEMD OWTS Manual, Section 2 to protect public health and water quality within El Dorado County as it has in the past. Special Design OWTS require the Qualified Professional and County to conduct inspections of the installation and the certification of the system by the Qualified Professional. The mitigations and system requirements are contained in the OWTS Manual which includes guidance on a variety of Special Design OWTS. Additionally, for any OWTS with Supplemental Treatment or an Alternate Dispersal System, an operating permit will be issued that will require the completion of inspections, maintenance, monitoring, and reporting. These requirements are detailed in the OWTS Manual under Operating Permits. D. CESSPOOLS (OWTS Policy 9.2.13) (OWTS Policy 9.4.1) (OWTS Manual Section 3H) A Cesspool is a hole excavated into the ground to receive Domestic Wastewater from a structure. A Cesspool does not have a tank or other water tight settling chamber nor does it have a proper pipe inlet/outlet or a Dispersal System to assist in Effluent treatment and safe disposal. Cesspools have not been approved for use in El Dorado County per our Sewage Disposal Standards dating to the mid 1970's. Cesspools are not authorized by this LAMP. Any existing Cesspool discovered by CDAEMD through our repair or complaint process or through an application to increase the capacity of any Existing OWTS shall be properly destroyed and replaced with an OWTS acceptable under this LAMP consistent with the same process noted in Section 3, Failing OWTS and Corrective Action. Mitigation measures may be imposed or reimbursement for such mitigation sought under California Health and Safety Code section 5412.5. Permits will not be issued for the construction of any Cesspool. E. RECREATIONAL VEHICLE HOLDING TANK WASTE (OWTS Policy 9.4.7) Under the State OWTS Policy, CDAEMD is prohibited from issuing permits for systems that receive a significant amount of wastes from Recreational Vehicle (RV) holding tanks. Such systems are regulated by the RWQCB. CDAEMD may issue permits for OWTS that receive RV holding tank wastes as long as those wastes are incidental to a more "normal" waste stream, such as a home with an RV waste Dump Station for use by the homeowner.

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F. STEPS IN THE PERMIT APPLICATION PROCESS (OWTS Policies 9.1.11 and 9.2.1) (OWTS Manual Section 1)

All OWTS permit applications for new construction, repairs, or additions within El Dorado County must be submitted to CDAEMD.

1. Steps in the Permitting Process In general, a complete OWTS permit application contains a completed application form, an accurate site plan, soils test results, and appropriate fees. 2. Soil Test Data Soil test data may include a soil profile, percolation tests, groundwater monitoring results, and/or soil boring logs. The specific test data required is determined by the type of system proposed and may be modified as the result of the tests conducted. Soil tests are typically required when:

• An Existing Parcel, created prior to soil test requirements for land divisions, is proposed for development;

• Grading or other soil disturbance has occurred in the previously tested/approved area; • The system is being shifted out of the previously tested/approved area; • An OWTS other than the type of system previously approved is being considered; • An Existing OWTS fails or is proposed for expansion and no previous soil test data is available

for the specific parcel.

CDAEMD staff will review soil percolation and other test data submitted with the application and determine if the tests are adequate or if additional tests are needed. Parcels created since 1975 (and on some earlier dates for a few land divisions) would have been created with eight (8) foot deep soil profiles to verify that at least four (4) feet of suitable soil exists. This soil test data does not expire and this data should be adequate to allow a permit to be issued for a Standard OWTS or Special Design OWTS with or without supplemental treatment, and without the requirement for additional testing. CDAEMD may nonetheless require additional testing if it determines that such additional testing would be prudent. If the initial soil test data indicate that a Tier 2 design is applicable project applicants may conduct additional tests to determine if soils at the site meet the more restrictive depth standards under this LAMP with the goal of constructing a Standard OWTS or less costly system. Additional tests would be required if the construction of a specific type of OWTS proposed for a site cannot be supported by the data on hand. In general, most parcels created prior to 1975 were created with inadequate (under this LAMP) soil tests or without soil test requirements at all. Parcels approved prior to 1975, which have not yet been developed, will require adequate soil testing to verify that these sites meet either the Standard OWTS (Tier 1) or Special Design OWTS requirements with or without supplemental treatment (Tier 2 LAMP).

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All required soil tests shall be conducted by, or be under the supervision of, a Qualified Professional such as a California Professional Civil Engineer, Professional Geologist, Registered Environmental Health Specialist (REHS), or a soil scientist and witnessed by CDAEMD (REHS) staff. For those parcels that have percolation tests and other soil data available, applicants must still develop and submit an accurate site plan for the proposed building project and the proposed OWTS. The site plan must take percolation and other soil test data and this guidance into account.

3. Application Site Plan (OWTS Manual Section 1F) The application form identifies the location of the property, owner, applicant if not the owner, contractor, proposed use, parcel size, specific assessor parcel number, and proposed water supply for the proposed project. The application identifies any previous land use projects that may have required that soil testing be conducted. The application also identifies the OWTS project as a new installation, a replacement, or a repair. A complete OWTS permit application includes a detailed, accurate site plan which at a minimum depicts the following: • The outline and dimensions of the parcel. • The property owner's name. • The assessor's parcel number for the property. • The address of the property. • A North arrow and scale. • The acreage of the property. • Dimensions/square footage/footprint and use of all structures. • Whether there are mobile homes or houses, whether there is a garage attached to the house, or

the location any other structures location on the parcel. • Easements shown and labeled. • All OWTS and well locations, both existing and proposed and the distance to all neighboring

OWTS and well(s). • The required 100% for residential or 300% for commercial Dispersal System replacement area. • All roads and driveways shown and labeled, including length, width, turn radius, and estimated

grade. • Drainages, waterways, water bodies shown and labeled, including roadside ditches, seasonal or

dry creek beds, and distance(s) from existing and proposed OWTS. • Distances to toe and/or top of slopes and cuts, whichever is appropriate. • Delineation of areas and depth of fill. • The locations of all percolation tests, soil profile pits, borings, and groundwater monitoring wells.

An accurate plan showing all percolation tests, soil profile pits, groundwater monitoring wells, and/or soil borings prepared by a Qualified Professional.

• All existing and proposed grading, including depths of cuts and fills. • Additional information may be requested for a proposed OWTS based on specific site features or

conditions.

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• Delineation of flood plain, when applicable. Additional information may be requested for a proposed OWTS based on specific site features or conditions and must be provided within the time requested. G. PERMIT APPLICATION REVIEW AND PERMIT ISSUANCE (County Ordinance Section

110.32.150) (OWTS Policy 9.2.3) (OWTS Policy 9.3.1 and 9.4.11) (OWTS Manual Section 1) CDAEMD staff will review all available soil test data, the site plan, and the application to determine if adequate information exists to issue an OWTS permit. After review, if it appears likely that the proposed OWTS (including 100%/300% replacement area) will fit into the site and will function properly, CDAEMD will issue an OWTS Permit. CDADSD and the City of Placerville require an approved OWTS permit before any building permits are issued. Grading or clearing of brush for the purpose of conducting a site evaluation and soil tests may require a grading permit. Any grading which damages or alters an approved or proposed sewage treatment dispersal area may be costly to correct, may delay the approval of a project, or may preclude the issuance of an OWTS permit. CDAEMD may allow variances from the State OWTS Policy with regard to horizontal separation. New installations and repairs shall conform to the State OWTS Policy to the greatest extent practicable. CDAEMD staff will work with applicants to determine if relocation of the proposed OWTS is possible to potentially avoid the requirement to add a Supplemental Treatment system. Records of the number, location, and description of permits issued for OWTS where a variance is granted shall be maintained for the annual report to the RWQCB. Variances will not be allowed for the creation of new parcels after the effective date of this LAMP.

H. FINAL INSPECTION (OWTS Policy 9.2.1) (OWTS Manual Section 1G) Once an OWTS permit has been issued, the OWTS can be installed. Such installation must meet all applicable requirements for OWTS construction in El Dorado County and any special conditions specified for that site or permit. CDAEMD staff may require a meeting with the Qualified Professional and installer at a pre-construction conference, as specified in the permit. The system must first be inspected by the Qualified Professional. Standard OWTS will receive an open trench inspection and a final inspection by CDAEMD staff. The Qualified Professional must inspect the open trench on all Special Design OWTS as well as supplemental treatment systems. If the Qualified Professional finds the OWTS to be in compliance with the system design and issued permit, the Qualified Professional must request a final inspection by CDAEMD staff. The system installation must be inspected and approved by CDAEMD before the system can be backfilled. If inspection reveals deficiencies, CDAEMD will issue a Correction Notice. If the inspection (or subsequent inspections if necessary) is satisfactory, CDAEMD will provide a final approval for the OWTS permit.

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Occasionally, CDAEMD will hold final approval on the OWTS permit pending the completion of specific conditions such as placement of backfill materials or final site grading. El Dorado County land use agencies require that OWTS are installed and final approval granted by CDAEMD before occupancy of structures is allowed. OWTS construction permits, once issued, will be valid for a period of two (2) years. Extensions and renewals of these permits will follow appropriate policy. I. PRIMARY AND REPLACEMENT AREA REQUIREMENTS (County Ordinance 110.32.130)

(OWTS Manual Section 1B) In addition to primary system design criteria, all OWTS design proposals, for both new construction and additions to an existing structure or approved use, must show 100%/300% replacement area for eventual replacement of the active OWTS when it reaches the end of its use or fails. Existing lots that were created prior to this LAMP may require that the 100%/300% replacement leach field is installed at the time the primary system is installed in the following situations:

1. The lot is less than one acre or is otherwise a difficult site to conduct a leach field repair, sites where adequate replacement space is limited, and sites with slopes greater than 30%.

2. The use is a commercial project, including food facilities. 3. The Director determines it necessary for other specified reasons.

A switching or alternating valve, to allow easy switching between fields, shall be installed at the time of construction where dual leach fields have been constructed to allow alternating use of fields at specified intervals. El Dorado County Ordinance allows appeals relating to alternate materials or methods of construction or design to be filed with the El Dorado County Building Appeals Board (County Ordinance Chapter 110.12). J. SEPTIC TANKS (OWTS Manual Section 3A) All Standard OWTS require the use of a water-tight septic tank to allow for the removal of solids and fats, oils, and grease from the wastewater prior to being discharged to a dispersal field. Most Supplemental Treatment OWTS will also require the use of a septic tank unless a settling chamber is a component of the treatment unit or treatment process. For specific information on the requirements for and sizing septic tanks, see OWTS Manual Section 3A. K. SUPPLEMENTAL TREATMENT AND ALTERNATE DISPERSAL OWTS (County

Ordinance 110.32.290, 110.32.300, 110.32.320) (OWTS Manual Section 2D) On parcels not meeting the groundwater separation in Tier 1 of the State OWTS Policy, a Supplemental Treatment OWTS or Alternate Dispersal OWTS may be used to reduce the required separation to a minimum of two (2) feet between the bottom of the dispersal discharge point and the highest anticipated depth to groundwater. Intermittent sand filters and recirculating sand filters can be constructed at sites from readily available materials or can be purchased as complete units from various manufacturers. Other Supplemental Treatment units, commonly known as proprietary treatment units, can be purchased for installation and use at sites. The Qualified Professional hired by the property owner to conduct the

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necessary soils tests shall design and properly size any treatment unit required for an OWTS on a particular parcel. Supplemental Treatment systems will require annual operating permits that specify monitoring requirements. L. OWTS LEACH LINE DISPERSAL SYSTEMS (OWTS Manual Sections 1, 2A, 2C and 2D) Dispersal Systems for Standard OWTS in El Dorado County typically consist of leach lines and the design is described in detail in the OWTS Manual. Dispersal Systems for OWTS with Supplemental Treatment can also include subsurface drip dispersal, mounds, shallow pressure distribution trenches (with rock or sand), and At-Grade Systems. The OWTS Manual, Section 2, C and D have specifics on the sizing, construction, design criteria, and monitoring of these systems. The Qualified Professional hired by the property owner to conduct the necessary soils tests shall designate and properly size the type of Dispersal System to be used, including, but not limited to, construction trench and backfill depths. The State OWTS Policy prohibits the installation of Dispersal Systems with less than two (2) feet of separation between the bottom of the Dispersal System and the highest elevation of a seasonal water table. This is reflected in the siting criteria of each specific Dispersal System. M. SETBACKS (OWTS Policy 9.2.3) (County Ordinance 110.32.240) (OWTS Manual Section 2B) Setbacks required in the siting and construction of septic tanks, Supplemental Treatment units, and Dispersal Systems are given in the OWTS Manual and in section 1D of this LAMP. It is anticipated that repairs to some failing OWTS will require a variance from these setbacks. Variances are evaluated by staff, and if deemed necessary, may be approved as long as the variances do not violate the prohibitions in Section 1C of this LAMP. CDAEMD is committed to meeting setbacks to the greatest extent practicable while maintaining the continued use or occupation of the property by owners. N. PROXIMITY TO PUBLIC SEWERS (OWTS Policy 9.2.10) (OWTS Policy 9.4.9) (County Ordinance

110.32.090, 110.32.110) CDAEMD staff will require connection to a public sewer whenever a new or Replacement OWTS is proposed within two hundred (200) feet of public sewers. CDAEMD staff will rely on the agency operating the public sewer to make the determination of availability based on proximity and feasibility discussed in Section 1C of this LAMP. If connection to public sewer is not feasible because the cost is two times greater than the replacement cost of the OWTS, then the proposed OWTS must meet the policies set forth in this LAMP. SECTION 3. FAILING OWTS AND CORRECTIVE ACTION (OWTS Policy 9.1) (County Ordinance 110.32.110) (OWTS Manual Section 4) All OWTS have the potential to fail due to age, misuse, and improper design or construction. The failure may result in wastewater backing up into plumbing fixtures, wastewater discharge to the ground surface, Effluent surfacing over a Dispersal System area, or wastewater or Effluent discharge into, and contamination of, potable groundwater or surface water. These failure conditions will require corrective

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action to mitigate potential risk to public health and/or contamination of the groundwater and the environment. Corrective action will be required in the event that an OWTS fails. Subsequently, enforcement actions may be necessary if corrective action is not completed within acceptable time frames. Traditional leach field systems, even when designed and constructed correctly, progressively fail resulting in diminished capacity of some or all of the leach lines. Effluent from septic tanks distributed into leach lines eventually forms a clogging Biomat, restricting the flow of Effluent into the soil for treatment. Effluent would then need to travel further into a leach line to find porous soil. Eventually, all of the leach lines would be clogged by this Biomat-coated soil and the system would no longer accept liquid, resulting over time in a failing system with sewage backing up into a structure or surfacing above a leach field. Tree roots are another cause for system failure. Tree roots can enter the pipe and rock of a leach line and over time totally plug the leach line, again resulting in either a sewage backup to structures or surfacing Effluent. Less frequently, some change may have been made to site contours or drainage that adversely impacts the leach field, such as site grading or driving vehicles over the leach field, or the presence of shallow groundwater that was not evident in soil pits or other tests, resulting in a failing system. These and other similar causes of a failing system are referred to as a major failure generally resulting in the need to perform a Major Repair including replacement of the entire leach line or other Dispersal System. Another example of major failure would be a septic tank that was somehow damaged or was no longer watertight allowing the discharge of untreated sewage or the infiltration of Groundwater into the tank. These issues could be the result of the tank settling over time, the growth of tree roots into the tank, driving heavy vehicles or storing heavy items over the top of the tank, or improper setting of the tank when the system was originally constructed. Examples of less serious or minor failures, and more easily repaired defects, would be a cracked distribution box or a crushed solid line between the septic tank and the distribution box, which would require a Minor Repair. Regardless of whether a major or minor repair is required, a permit to perform the repair is required from CDAEMD and all systems, after repair, must be in compliance with this LAMP. Whatever the reason or severity, a failing system, or component, that may result in surface or groundwater contamination or a public health hazard, shall be corrected without delay under a valid OWTS permit issued by CDAEMD.

A. PROGRESSIVE FAILURE OF A LEACH FIELD As discussed in the previous section, a newly constructed leach field progressively fails through normal use over time. Every system is different, depending on the soil type and construction variables, as is every household’s use of a system. Progressive failure(s) may take several years to many decades to completely

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result in a failing leach field with sewage backups or surfacing onto the ground surface. The life span of a leach field system is unpredictable due to these variables. This progressive failure or diminished capacity is expected and is normal. This does not mean that the system is failing until liquid is no longer accepted into the soil. It does mean that the system is working as designed and as expected, yet reaches the end of its useful life. Short of excavating into a leach field, or measuring liquid levels in inspection wells into leach fields (when equipped), there is no accepted test that can demonstrate the degree toward which a system has progressed towards total failure or measure how the capacity of the leach field has diminished. There are some simple things that can be done to limit or delay this diminished capacity by progressive failure and extend the life of a leach field or other Dispersal System. One inexpensive strategy is to install an outlet filter on a septic tank, which is required by CDAEMD. This filter will remove larger solids particles not removed in the septic tank to delay the formation of a thick, plugging Biomat in a Dispersal System. Another, more costly, strategy is to pressure dose the entire leach or Dispersal System equally. This will dose the entire Dispersal System equally instead of dosing only the first few feet of a leach line as has been the practice in the past. Many Alternate Dispersal Systems use one or both of these methods to extend the life span of Dispersal Systems by delaying the formation of a thick Biomat. All OWTS require periodic pumping, inspections, or maintenance to keep the system in proper working order and assure adequate treatment of Effluent. Owners of property served by an OWTS must maintain their OWTS in good working order as failures may result in groundwater or local surface water contamination, health hazards, and costly corrective actions. Owners of OWTS that utilize a supplemental treatment shall contract with a Service Provider who is capable of operating, monitoring, and maintaining an OWTS in compliance with this LAMP and carrying out the appropriate inspections, maintenance, monitoring, and reporting required in the OWTS operating permit conditions.

B. CORRECTIVE ACTION REQUIREMENTS (OWTS Policy 3.3.1) (OWTS Policy 9.2.1) (OWTS Manual Section 4) CDAEMD will conduct an investigation in a timely manner to determine the validity of an OWTS repair/replacement permit application, complaint report, or other notification of a failing OWTS or component, or the discovery of a Cesspool in use.

1. Upon receipt of a complaint report from a member of the public or a notification by a property owner or Service Provider, a violation file will be generated with an assigned tracking number.

2. Upon investigation and confirmation of a failing OWTS, CDAEMD will issue a Notice of Violation (NOV) directing the property owner to eliminate the immediate health hazard through pumping of the septic tank by a licensed septic tank pumper or by the elimination of wastewater flows from the structure. These actions shall continue until the system has been repaired/replaced and final approval granted by CDAEMD. If known, the NOV shall note why the system is failing and include specific corrective actions needed. CDAEMD will also require proper destruction of any Cesspool found in use by issuing a NOV directing abatement. A new OWTS will be required for use. The Notice of Violation (NOV) shall require repairs to the OWTS, as needed, within a reasonable time frame. An inspection report or warning notice may also be issued to the

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property owner at the time of the site inspection. Subsequently, a NOV detailing required corrective actions and time frames may be issued if the identified failure cannot be corrected immediately.

3. The proposed repair/replacement by a property owner and/or contractor in an OWTS Permit Application shall be evaluated by CDAEMD to ensure it meets the minimum design requirements of this LAMP or that the proposed repair is otherwise in substantial conformance to the greatest extent practicable.

4. Any OWTS component failure, other than those listed in 5 and 6 below, such as a broken distribution box or broken piping connection (a minor failure), shall have that specific component repaired in a timely manner, and inspected by CDAEMD, so the OWTS can return to proper functioning condition without the requirement to bring the entire OWTS into compliance with this LAMP.

5. In the event of failure of a septic tank (a major failure), such as a baffle, "tee," loss of structural integrity, or groundwater intrusion or sewage/Effluent discharge, CDAEMD will require that the septic tank be repaired or replaced to bring the tank into compliance with the septic tank specifications in this LAMP in a timely manner. An OWTS Permit application must be submitted and a permit must be issued by CDAEMD noting the corrections required. The system may not be backfilled or placed into use without an inspection and final approval from CDAEMD.

6. In the event of the failure of a Supplemental Treatment OWTS or an Alternate Dispersal OWTS (a major failure), the failing system and/or components shall be brought into compliance with this LAMP within a timely manner. Replacement of the failing system with a Standard OWTS or Special Design OWTS will be specified in an OWTS Permit issued by CDAEMD. The OWTS may not be backfilled or placed into use without an inspection and final approval from CDAEMD. Supplemental treatment may be required in situations where ground or surface waters have been impacted by the failing OWTS. Failure of the septic tank, Supplemental Treatment OWTS, or Dispersal System may also lead to failure and required replacement of other components of the OWTS. Proper pumping, inspections, maintenance, and monitoring of the OWTS would be expected to reduce the frequency and severity of a failing component or multiple components.

7. Soil tests by a Qualified Professional may be required, at the discretion of CDAEMD, to properly characterize the site with a failing OWTS. Groundwater separation requirements from the bottom of the Dispersal System and the highest anticipated groundwater level for repairs are the same as those for newly constructed systems: minimum of five (5) feet (based on soil percolation rates) for standard systems and no less than two (2) feet for systems with Supplemental Treatment and/or an Alternate Dispersal System. Repairs must meet the LAMP requirements to the greatest extent practicable.

8. Required correction(s) shall be completed under permit and inspection from CDAEMD within specified time frames. No component of an OWTS shall be backfilled and placed into use until authorized in writing by CDAEMD staff after an inspection confirms substantial compliance with valid CDAEMD permit conditions and the standards in this LAMP.

9. Failure to complete the required corrective action within the time frames given will result in enforcement action which may include referral to the El Dorado County District Attorney or

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Code Enforcement staff and could ultimately result in condemnation of the structure for immediate health hazard to residents and/or the public pursuant to Chapter 9.02.300.

10. CDAEMD will pursue, but cannot guarantee the availability of, potential funding for required corrective actions, such as the State Water Board's Clean Water Revolving Fund for mini-loans, and upon request, will advise property owners of other known funding sources depending on their situation.

C. SUBSTANDARD SYSTEMS The CDADSD process allows CDAEMD to evaluate sizing of an OWTS to ensure it is adequate for replacement residence or bedroom additions. Parcels with OWTS that are found to be substantially out of compliance with this LAMP shall be prohibited from having future additions to structures or other modifications to the property that would potentially increase wastewater flow to the OWTS or decrease the amount of useable area available for the OWTS. A new OWTS permit will be required to repair, replace, or add OWTS components to bring the system into compliance with this LAMP to the greatest extent practicable. The permit application would require any fees, test data, or system designs plans or specifications deemed necessary by the Director.

SECTION 4. LAND DIVISIONS OF PARCELS SERVED BY OWTS (OWTS Policies 9.1.1, 9.1.2, 9.1.5, 9.1.6, 9.1.7 and 9.4.10.4) Prior to this LAMP, within El Dorado County, a site was required to have at least four (4) feet of soil and a minimum area for wastewater treatment dispersal to qualify for a land division when not served by public sewer. This LAMP will still allow the division of parcels with less than five (5) feet of soil to occur; however, supplemental treatment systems and/or Alternate Dispersal Systems may be required and leach fields will ultimately be much shallower than under previous standards to protect water quality.

1. Proposed Dispersal Area (OWTS Manual Section 1C) Table 1. Minimum Disposal Area based on Percolation Rate.

PERCOLATION RATE (minutes/inch)

MINIMUM DISPOSAL AREA (square feet)

Less than 10 6,000 11-20 8,000 21-40 10,000 41-60 12,000 61-80 14,000 81-100 16,000 101-120 18,000 Over 120 Not suitable for development

a. Each parcel shall contain one or more dispersal areas, each consisting of minimum disposal area

shown in Table 1 of useable dispersal material in locations which could reasonably be utilized by a structure built at a desirable location and feasible site.

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b. Dispersal area shall not include: (1) Land subject to flooding. In case of disputes concerning flooding potential, the flooded area

shall be determined by calculating the expected 10-year frequency flood. (2) Land closer than two hundred (200) feet to a lake or reservoir, measured from the high water

line or one hundred (100) feet if down slope from the lake or reservoir. (3) Land closer than two hundred (200) feet to any spring or one hundred (100) feet if downhill

from the spring. (4) Land within one hundred (100) feet of any existing or proposed private well site for the parcel

or any adjoining parcel and two hundred (200) feet from public wells. (5) Land closer than one hundred (100) feet to an intermittent, seasonal, or perennial waterway

measured from the top of the bank or other physically evident high water line. An intermittent stream is one which may continue to flow for five days or more after the passage of a storm.

(6) Land closer than fifty (50) feet to an Ephemeral Stream, measured from the edge of a channel. (7) Land closer than fifty (50) feet downhill from an irrigation ditch or canal. (8) Land closer than fifty (50) feet uphill from an existing or proposed cut. (9) Land with a grade steeper than 30%.

(10) Filled land, unless the fill is engineered for sewage dispersal and approved by CDAEMD. (11) Gravel bars of very porous materials adjoining a stream or body of water. (12) Land used for utility or road easements. Overhead utility easements may be included if the

utility, entity, or agency holding the easement gives a permanent and irrevocable release, easement, or license for sewage dispersal within the easement.

(13) Dispersal System within twelve hundred (1,200) feet of Public Water System intake point.

2. Minimum Parcel Size The average density for any subdivision of property made by Tentative Approval pursuant to the Subdivision Map Act occurring after the effective date of this LAMP shall not exceed the allowable density values in Table 2 for a single-family dwelling unit, or its equivalent, for those units that rely on OWTS.

Table 2: Allowable Average Densities per Subdivision under Tier 1. Average Annual Rainfall (in/yr)

Allowable Density (acres/single family dwelling unit)

0 - 15 2.5 >15 - 20 2 >20 - 25 1.5 >25 - 35 1 >35 - 40 0.75 >40 0.5

3. Dispersal Material Characteristics Useable dispersal material has both the following characteristics:

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a. Percolation rates between one (1) and one hundred-twenty (120) minutes per inch when tests are conducted by the methods specified in the OWTS Manual (Section 1A) or Manual of Septic Tank Practice by the U.S. EPA.

b. Depth to a seasonal water table shall be at least five (5) feet.

4. Percolation Test, Test Pits, and Groundwater Monitoring a. Percolation Tests. Four (4) percolation tests representative of the dispersal area shall be conducted

on each proposed dispersal area. b. Test Pit. At least one test pit shall be excavated on each lot. The soil profile shall be logged by a

person qualified to perform percolation tests and backfilled. CDAEMD staff must be present to observe test pit excavation.

c. Groundwater Monitoring. (1) The height of the seasonal high groundwater shall be determined by wet weather testing when

any of the following is present: (a) Vegetation tolerant of or indicative of a high water table present or in the vicinity of the

parcel. (b) High groundwater has previously been found in the vicinity. (c) Other conditions or historical data preclude accurate determination of the groundwater

levels. (d) The test pit indicates less than five (5) feet of the dispersal material over an impervious

stratum or eight (8) feet for lots less than one acre or for community leach fields. (e) Free water from seepage is observed in the test pit.

(2) The height of the seasonal high groundwater shall be determined by actual measurements of observation wells during periods of maximum soil moisture content, after sufficient precipitation has occurred to meet or exceed field capacity of the soil, and produce a response in observation wells acceptable to CDAEMD. (a) Direct Observation. Groundwater measurements shall be taken at the time and intervals

specified by the CDAEMD in response to local conditions. Except as otherwise directed, measurements shall be taken at approximately monthly intervals from January 1 to April 30. At least one observation well shall be included within each proposed dispersal area suspected of having groundwater less than five feet below the ground surface, except where a nearby monitoring well shows groundwater contours representative of the proposed dispersal area. For a site to be acceptable for a Standard OWTS, the groundwater during the monitoring period shall not be less than five (5) feet below the ground surface. If this limit is exceeded on any observation, weekly observations shall be recorded throughout the remainder of the wet weather season to ensure that the standards are not exceeded for longer than any two-week period. The depth to groundwater shall never be less than two (2) feet on any observation. If seasonal rainfall up to the April 30 cutoff date has not exceeded 80% of the

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normal rainfall, as determined by the nearest rainfall reporting station approved by the CDAEMD, during the period from December 1 to April 30, testing shall be continued the next year. However, CDAEMD may accept monitoring in years with less than the required amount of rainfall as long as the results appear to represent the highest groundwater depth for the site.

d. All of the testing shall be done by, or under the supervision of, a Qualified Professional. The results of all percolation tests and groundwater monitoring shall be reported and the logs of all excavations shall be submitted to CDAEMD. They shall be accompanied by a plot plan to scale showing the test, well, and pit locations. The map shall include two (2) foot contour intervals. The Director may disregard any test or log that, in his/her sole discretion, does not represent the soil conditions of the parcel. Logs or tests that do not appear to represent soil condition at the parcel may be rejected by CDAEMD.

5. Soil Analysis As an alternative to direct observation, an application may be submitted to CDAEMD for individual evaluations utilizing "Conditions Associated with Saturation." a. “Conditions Associated with Saturation” include:

(1) Reddish brown or brown soil horizons with gray (Chromas of three or less) and/or red or yellowish red mottles;

(2) Gray soil horizons, or gray soil horizons with red, yellowish red, or brown mottles; (3) Dark-colored highly organic soil horizons; or (4) Soil profiles with concentrations of soluble salts at or near the ground surface.

b. If conditions associated with saturation do not occur in “Soil with Rapid or Very Rapid Permeability,” saprolite, or fractured Bedrock, prediction of the highest level of the water table shall be based on direct observations.

c. "Soil with Rapid or Very Rapid Permeability" means (1) Soil which contains 35% or more of course fragments two (2) millimeters in diameter or larger

by volume with interstitial soil of sandy loam texture or coarser; (2) Coarse textured soil (loamy sand or sand and as classified in a Soil Textural Classification Chart);

or (3) Stone, cobbles, gravel, and rock fragments with too little soil material to fill interstices larger

than one (1) millimeter in diameter. d. Saprolite means weathered material underlying the soil that grades from soft thoroughly

decomposed rock to rock that has been weathered sufficiently so that it can be broken in the hands or cut with a knife. It does not include hard Bedrock or hard fractured rock. It has rock structure instead of soil structure.

For a site to be acceptable under this method for a Standard OWTS, groundwater shall not be less than five (5) feet below the ground surface. Lots less than one (1) acre in size or community dispersal fields shall be evaluated using either direct observation or soils analysis. 6. Limitations.

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a. No lot shall be created for which a seepage pit is the only feasible method of sewage disposal. b. In subdivisions where no adequate impervious stratum lies beneath the one which may receive

Effluent and above the useable groundwater, no lots shall be approved where the usable material beneath any leach line will be less than five (5) feet. An adequate impervious stratum exists if the stratum: (1) Confines under pressure the usable groundwater so that wells drilled in it have a higher static

water level at which the driller first encounters the water; (2) Consists of material with a percolation rate slower than one hundred twenty (120) minutes per

inch when tested by the method prescribed in the OWTS Manual or Manual of Septic Tank Practice by the U.S. EPA.; or

(3) Supports a perched water table. c. When potential is noted for inadequate treatment in the underlying or dispersal material prior to

Effluent reaching usable groundwater or the surface, additional tests to prove that travel time is sufficient shall be done, or the project shall be recommended for disapproval and OWTS permits will not be approved.

7. Lots created for uses which will not generate liquid wastes a. Lots proposed and suitable for agricultural, commercial, industrial, or recreational uses that will not

generate liquid wastes and do not require the regular presence of workers or employees are not subject to the dispersal area or testing requirements of the above portions of this subsection.

b. Each of these parcels shall be identified on the recorded map with this statement: "This parcel is not approved for any use that will generate liquid waste. No permit to dispose of sewage or other liquid waste generated by the uses of this property will be issued until applicable provisions of state and local law and the LAMP and County Ordinance Chapter 110.32, as amended, have been complied with.”

8. Maps a. Tentative.

All tentative maps shall show for each parcel the location, boundaries, and calculated square footage of the dispersal area(s). The calculations, as determined by the procedures of Section 4 of this LAMP, shall be submitted concurrently with the tentative land division application. If individual wells are proposed, the map shall show all existing and proposed well sites. Additionally, the map shall show proposed building envelopes and driveway locations. The map shall be to scale and show topography in the dispersal area at two (2) feet contour intervals and location of the test pits and percolation tests.

b. Final and parcel maps. For each parcel, the area(s) qualifying as dispersal area shall be clearly delineated and labeled on the final or parcel map. If individual wells are proposed, the map shall show all existing well sites with 100-foot setback radius clearly shown. Additionally, the map shall show proposed building envelopes and driveway locations. The map shall be to scale and show topography in the dispersal area at two (2) feet contour intervals and location of the test pits and percolation tests.

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SECTION 5. GROUNDWATER SEPARATION REQUIREMENTS FOR ONSITE WASTEWATER TREATMENT SYSTEMS AND OVERALL SOIL DEPTH DETERMINATIONS (OWTS Policy 9.5) (OWTS Manual Section 1) These requirements will be used for determining soil depths and groundwater levels when siting and designing OWTS on Existing Parcels to accomplish the following:

• Protect the groundwater quality by ensuring proper treatment of the sewage Effluent prior to its entering into groundwater.

• Protect the public health from failing OWTS caused by high groundwater. • Provide a methodology for the evaluation of potential building sites using OWTS with regard to

maintaining minimum groundwater separation requirements of the adopted State OWTS Policy. A. MINIMUM DEPTHS TO GROUNDWATER AND MINIMUM SOIL DEPTH FROM

THE BOTTOM OF THE DISPERSAL SYSTEM (OWTS Policy 9.4.8) (OWTS Manual Section 2) Pursuant to the State OWTS Policy, the minimum depth to the anticipated highest level of groundwater below the bottom of the leaching trench, and the native soil depth immediately below the leaching trench, shall not be less than the following:

Table 3. Native Soil Depth based on Percolation Rates.

Percolation Rate: Native Soil Depth

Percolation Rate 1 to 5 MPI Twenty (20) feet

Percolation Rate >5 to 30 MPI Eight (8) feet

Percolation Rate>30 to 120 MPI Five (5) feet

MPI = Minutes per Inch (the time it takes for a column of water to drop one (1) inch in a controlled percolation test).

It is CDAEMD intent, through this LAMP, to allow installation of systems in soils between one (1) MPI and one hundred twenty (120) MPI. For OWTS with Supplemental Treatment and/or for some Alternate Dispersal Systems, the required separation above may be reduced from that shown above but must not be less than two (2) feet. This reduction is allowed due to the level of pretreatment provided by the Supplemental Treatment and/or alternate Dispersal System to replace, or enhance, treatment of Effluent by soil. Groundwater typically fluctuates seasonally depending on local geology and precipitation levels. Groundwater levels fall in response to drought and well extraction, and rise in response to precipitation, flood agricultural practices, and possibly irrigation from residential development. OWTS failures due to high groundwater result in sewage Effluent backing up into homes and/or surfacing on the ground creating public health hazards and can contribute to the contamination of potable groundwater and surface water resources.

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The overall soil depth and depth to the highest anticipated groundwater level must be determined for each site proposed for an OWTS. B. SOIL PROFILE PITS (OWTS Policy 9.1.1) (OWTS Policy 9.1.3) (OWTS Policy 9.1.5) (OWTS Policy

9.1.6) (OWTS Manual Section 1) All parcels shall have soils tests to determine suitability for wastewater dispersal. This may include, depending on the type of OWTS proposed, soil profile pits, soil borings, and percolation tests and may require groundwater monitoring. The results of soil profile pits (test pits) and borings will assist in determination of site soil depth and the highest anticipated depth to groundwater. At least one test pit shall be excavated on each lot, the soil profile shall be logged by a Qualified Professional and then the test pit shall be backfilled. When unsafe site conditions or the depth is beyond what can be evaluated by a test pit, soil borings conducted by a Qualified Professional with experience in boring interpretation must be used to determine overall soil depth and depth to groundwater where deeper depths and unsafe site/soil conditions exist. All pits/borings will be excavated for examination by CDAEMD staff. Tests performed to create new parcels (land divisions) are discussed in Section 4 of this LAMP. The soil profile or boring shall have enough information to allow a determination of whether or not groundwater is present and, if so, the highest anticipated depth to water and the overall depth of soil at the site. 1. Soil pits/borings are to be excavated a minimum of eight (8) feet in depth. Deeper borings to

determine overall soil depth and depth to groundwater will be recommended if it is believed that soils at the site meet the minimum depth beneath the bottom of the Dispersal System for a Standard OWTS.

2. All soil profile pits and deep borings shall have soils described as follows: • For each pit or deep boring, identify the property owner, pit/deep boring number, the slope percent

of the area of the pit/boring, the date logged, and the Qualified Professional logging the pit/boring. • All pit or deep boring logs, including failing pits/borings must be submitted to CDAEMD for review. • Within each pit/boring, from the surface to bottom of the excavation, the following must be provided

for each horizon: o Depth of each horizon within the pit/boring o Color(s) within each horizon o Amount (by percent) and size of gravels o Soil texture o The number, size, and prominence of soil mottles, where present o Soil structure o Consistency o Boundary thickness between horizons

C. GROUNDWATER MONITORING (OWTS Manual Section 1) (Ordinance 110.32.230) The end result of test pits or soil borings is to have knowledge of the useable soil depth and depth to groundwater at the site. However, it is not always possible to determine the depth to seasonal water by observing soil pits or borings alone. When the highest anticipated depth to groundwater cannot be

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determined with the use of test pits or soil borings, CDAEMD may require groundwater monitoring wells to be installed to determine the highest anticipated depth to groundwater. Groundwater monitoring wells may be indicated if the following conditions exist:

• Vegetation tolerant of, or indicative of, a high water table present on or in the vicinity of the parcel. • High groundwater has previously been found in the vicinity. • Other conditions or historical data preclude accurate determination of the groundwater levels by

dry weather observations. • The test pits indicate less than five (5) feet of disposal material over an impervious stratum. • Free water seepage is observed in the test pit.

Maps showing the locations of monitoring wells constructed at the site, and the monitoring results, must be submitted to CDAEMD along with soil profile information and percolation test results. Groundwater monitoring, as with other soil tests, shall be conducted by a Qualified Professional. The height of seasonal high groundwater shall be determined by actual measurements of observation wells during periods of maximum soil moisture content, after sufficient precipitation has occurred to meet or exceed field capacity of the soil and produce a response in observation wells acceptable to the CDAEMD.

1. Well Construction Groundwater monitoring wells, for OWTS purposes, are typically completed as follows: a. Soil profile test pits are converted to groundwater monitoring wells by placing a perforated pipe

into the pit prior to backfilling with native soil. b. A hole is drilled or bored to a desired depth, a perforated pipe is placed into the hole, clean pea

gravel is placed around the perforated pipe, and a surface concrete seal is placed. c. Well construction materials specifications:

• Perforations will be engineered slots, rather than drilled holes; • Filter fabric will be used to cover the perforations in soil pits; • Use of solid pipe for the upper two (2) feet of the well is required; • A minimum of twelve (12) inches of concrete will be placed on the upper annular space of

drilled/bored wells; • A minimum two (2) mil. plastic sheet may be draped over entire excavated area of a soil pit used

as a monitoring well to exclude direct access of surface water into the backfilled pit. • At no time is a pit or bored/drilled hole to extend through a restrictive layer such as hardpan,

Bedrock, impervious clay stratum, or similar layer.

2. Observation Groundwater monitoring well placement and depth must be representative of site conditions, soil percolation rate, and the type of OWTS proposed for the site. For example, a five (5) foot deep well is not adequate if you are proposing to install a Standard OWTS (no alternate treatment or Dispersal System) where the percolation rate at the site is between five (5) and thirty (30) MPI. These conditions would require eight (8) feet of soil beneath the bottom of a Dispersal System.

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From December 1 to April 30, at least 80% of historical normal average rainfall must be received in the vicinity of the proposed OWTS for the monitoring data to be accepted by CDAEMD. The CDAEMD may accept monitoring in years with less than the required amount of rainfall as long as the results appear to represent the highest groundwater depth for the site. Direct Observation measurements shall be taken at the times and intervals specified by CDAEMD in response to local conditions. CDAEMD may allow measurements to be taken at monthly/weekly intervals from January 1 to April 30. At least one observation well shall be included within each proposed dispersal area suspected of having groundwater, where the groundwater depth cannot be determined by observation using a soil pit. Groundwater ideally would not be less than that specific depth required for the type of system proposed. Fill, engineered for soil dispersal of Effluent, may be placed to provide the necessary soil depth and separation from seasonal groundwater where at least one (1) foot of native soil is present. If monthly depth measurements are within one (1) foot of the depth required for the specific type of system proposed, weekly observations shall be recorded throughout the remainder of the wet weather season to better define the seasonal water table. 3. Well Depth Wells should be constructed to a depth of at least (5) five feet, to a restrictive layer, or to depths deemed necessary for the type of system proposed at a site. In no case is a well to be constructed through a restrictive layer such as hardpan, Bedrock, impervious clay stratum, or similar layer. A log of soil strata encountered during well construction is to be submitted with the monitoring results. The number, placement, and depth of wells should be specified by a Qualified Professional prior to construction. 4. Soil Analysis of Conditions Associated with Saturation As an alternative to direct observation, an application may be submitted to CDAEMD to evaluate individual sites where conditions associated with saturation exist. Section 4 of this LAMP provides guidance on assessing conditions associated with saturation. 5. Site Evaluation Procedures for Determination of Groundwater Using “Conditions

Associated with Saturations” Applications for site evaluation shall be made to CDAEMD on approved forms. Each application must be signed by the owner or his legally authorized representative and accompanied by all required exhibits and appropriate fee. Incomplete applications will be rejected.

D. PERCOLATION TEST PROCEDURE

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(OWTS Policy 9.1.1) (OWTS Policy 9.1.3) (OWTS Policy 9.1.5) (OWTS Policy 9.1.6) (OWTS Policy 9.5) (OWTS Manual Section 1A) This procedure establishes clear direction and methodology for percolation testing in El Dorado County. The objectives are to determine the area necessary to properly treat and disperse sewage underground; to size the OWTS with adequate infiltration surface area based on expected hydraulic conductivity of the soil and the loading rate; and to provide for a system intended to allow for a long-term expectation of satisfactory performance. All percolation testing for Dispersal Systems shall be conducted through the use of these percolation test procedures. The tests shall be performed by or be under the supervision of a Qualified Professional. Any deviation shall be allowed only after receiving written approval by CDAEMD.

1. Percolation Test Hole Procedures a. Number of Percolation Holes

(1) Four (4) tests are required (2) Additional tests may be required on a site specific basis for reasons that include the

following: (a) Unacceptable or failed tests (b) Areas of the dispersal field requiring defined limits for exclusion (c) The dispersal field is located out of a concentrated area (d) Soil conditions are variable or inconsistent (e) The need to verify suitable soil permeability beneath the chosen leach field depth

b. Depth of Percolation Test Holes (1) Percolation test-hole depth shall be representative of the proposed Dispersal System

trench bottom depth or twelve (12) inches for systems such as an at-grade or drip Dispersal System.

(2) For each lot of proposed land divisions (see LAMP Section 4), two (2) to three (3) tests are to be conducted at a depth of three (3) feet and the remainder at a depth of one (1) foot.

(3) Conditions which may require percolation testing deeper than dispersal depth include: (a) Consolidated rock or suspected impervious soil layers beneath the site; (b) Slopes exceeding 30%; (c) Other factors as might be determined by sound site evaluation practices.

c. Location of Percolation Test Holes Percolation test holes shall be excavated in the area representing the proposed location of the Dispersal System or within an expected proposed disposal area of a proposed parcel to be created by a land division. Percolation tests shall be conducted in soils suitable for dispersal of Effluent that otherwise meet soil depth and groundwater depth for the type of system proposed for construction. Test holes shall be representative of the dispersal area demonstrating site conditions throughout the entire wastewater treatment system or proposed sewage dispersal area (land divisions) with equal consideration of primary and reserve Dispersal Systems. d. Identification of Percolation Test Holes

(1) When specifically requested, locations are to be staked and flagged so the test-hole locations can be located.

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(2) They are to be identified as to location on the site plan with: (a) A test hole number or letter; (b) Depth of the test hole; and (c) Proposed lot/parcel number or letter if associated with a subdivision or other land use

project requiring soil testing. e. Construction of Percolation Test Holes

(1) Diameter of percolation test holes shall be a minimum of six (6) inches. (2) If a shallow backhoe excavation is used, a percolation test hole at twelve (12) to fourteen

(14) inches in depth shall be excavated into the bottom of the backhoe bucket trench (the bottom of the percolation hole within this trench is to be at the percolation test-hole depth required for the project).

f. Preparation of the Percolation Test Holes (1) Scarify the sides and bottom of the holes, as needed, to remove the soil surface areas that

became smeared by the auger or other tool used to excavate the hole. (2) Remove as much loose material as possible from the hole. (3) Add two (2) inches of clean pea gravel to protect the bottom from scouring.

2. Presoaking the percolation test holes

a. Procedure (1) Carefully fill the test hole with a minimum of twelve (12) to fourteen (14) inches of clear

water over the gravel or to the ground surface in shallower test holes. (2) Refill the test hole as needed or otherwise maintain clear water in the hole for a minimum

of four (4) hours. After four (4) hours, allow the water column to drop overnight. Testing must begin twenty-four (24) hours after water was first added to the hole.

b. Saturation and swelling (3) Saturation means that the void spaces between soil particles are full of water. This can be

accomplished in a short period of time. (4) Swelling is caused by the intrusion of water into the individual soil particles. This is a slow

process, especially in clay-type soil, and is the reason for requiring a prolonged soaking. (5) To prevent sloughing of the sidewall in unstable soils, the following options may be

employed: (a) Hardware cloth such as a one-eighth (1/8) inch grid; and (b) Perforated pipe or other rigid liner.

3. Determination of Percolation Rates

Depending on the soil type and permeability, and the results of the presoak, variations in the procedures used for determining percolation rates can be allowed. Testing shall proceed based on the conditions outlined in the following cases: a. Case 1- Water remains overnight in the test hole following initiation of the twenty-four (24)

hour presoak. (1) Adjust the depth of water over the gravel to six (6) inches.

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(2) Measure the drop in the water level over a single thirty (30) minute period and calculate the percolation rate.

b. Case 2- No water remains twenty-four (24) hours after the presoak period was initiated. (1) Begin the test twenty-four (24) hours after presoak was initiated. (2) Fill the hole with six inches of water over the gravel. If, after the first two (2) fillings, the

water column seeps away in less than thirty (30) minutes, go to Case 3. If water remains after thirty (30) minutes, complete the test by adjusting the water depth to six (6) inches over the gravel and record the drop at the end of every thirty (30) minute period.

(3) Including the first two (2) readings above, continue the readings and refill every thirty (30) minute interval for four (4) hours.

(4) The last water level drop is used to calculate the percolation rate. c. Case 3 - No water remains in the hole after the first two, thirty (30) minute periods.

(1) Refill the test hole to six (6) inches above the gravel. (2) Record the water level drop at ten (10) minute intervals for a period of one (1) hour,

refilling to the six (6) inch depth after each reading. (3) The last water level drop us used to calculate the percolation rate.

NOTE: In all three of these cases, readings shall be taken from a fixed reference point and shall be accurate to 1/16 of an inch.

4. Calculations and Measurements a. Calculation Example

The percolation rate is reported in minutes per inch. For example, a thirty (30) minute time interval with a 3/4 inch fall would be thirty (30) minutes divided by 3/4 inch equals forty (40) minutes per inch (MPI). In the example of a ten (10) minute interval with a 2-inch drop, the calculation is ten (10) minutes divided by two (2) inch equals five (5) minutes per inch (MPI).

b. Measurement Principles (1) The time interval for readings are to reflect the actual times and are to be maintained as

near as possible to the intervals outlined for the test (10 or 30 minutes). (2) Measurements to the nearest 1/16 inch should be adjusted to the slowest rate, e.g., a

reading observed between 3/8 inch and 5/16 inch (80 MPI and 96 MPI) would be reported as the slower of the two, or 96 MPI.

5. Special Considerations Percolation rate measurements are to be made from a fixed reference point and shall be from a platform that is stable and represents the center of the test hole. Percometer devices are encouraged and are required when conducting tests greater than sixty (60) inches below the ground surface. a. All test data and other required information is to be submitted to the CDAEMD on forms and in

a format acceptable to the CDAEMD with appended data or information as needed.

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b. Reports shall be signed with an original signature from the Qualified Professional who either performed or supervised the testing.

c. Qualified Professionals who employ technicians are responsible for the work performed by the technicians. It is incumbent upon the Qualified Professional to properly train, equip, and supervise anyone performing work under his or her direction and license.

d. The percolation test is only one of several critical factors in siting an OWTS. Site considerations may require special evaluation by a Qualified Professional to technically address issues such as high groundwater, steep slope, nitrate impacts, and cumulative impacts such as mounding and loading.

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APPENDICES INDEX

A. MAP EL DORADO COUNTY BOUNDARIES B. PORTER-COLOGNE CONCERNING SEWAGE DISPOSAL IN THE TAHOE BASIN C. DEFINITIONS

APPENDICES

APPENDIX A

Appendix A. County of El Dorado – Regional Water Quality Control Board Jurisdiction

Central Valley Jurisdiction

Lahontan Jurisdiction

County Boundary

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EXCERPT FROM PORTER-COLOGNE

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Excerpt from Portor-Cologne

CHAPTER 12. SPECIAL WATER QUALITY PROVISIONS [13950. - 13952.5.]

(Chapter 12 added by Stats. 1969, Ch. 800.)

§ 13950.[Lake Tahoe Basin cesspools] Notwithstanding any other provision of law, upon any district in the Lake Tahoe Basin providing in any area of the district a sewer system and treatment facilities sufficient to handle and treat any resultant waste and transportation facilities sufficient to transport any resultant effluent outside the Lake Tahoe Basin, the further maintenance or use of cesspools or other means of waste disposal in such area is a public nuisance and the district shall require all buildings from which waste is discharged to be connected with the sewer system within a period of not less than 90 days from the completion of such system and facilities. (Added by Stats. 1969, Ch. 800.) §

13951.[Exceptions] Notwithstanding any other provision of law, on or after January 1, 1972, waste from within the Lake Tahoe watershed shall be placed only into a sewer system and treatment facilities sufficient to handle and treat any such waste and transportation facilities sufficient to transport any resultant effluent outside the Lake Tahoe watershed, except that such waste may be placed in a holding tank which is pumped and transported to such treatment and transportation facilities.

As used in this section “waste” shall not include solid waste refuse.

The further maintenance or use of cesspools, septic tanks, or other means of waste disposal in the Lake Tahoe watershed on or after January 1, 1972, by any person, except as permitted pursuant to this section, is a public nuisance. The occupancy of any building from which waste is discharged in violation of this section is a public nuisance, and an action may be brought to enjoin any person from occupying any such building.

This section shall not be applicable to a particular area of the Lake Tahoe watershed whenever the regional board for the Lahontan region finds that the continued operation of septic tanks, cesspools, or other means of waste disposal in such area will not, individually or collectively, directly or indirectly, affect the quality of the waters of Lake Tahoe and that the sewering of such area would have a damaging effect upon the environment.

This section shall not be applicable to any area or areas within the Fallen Leaf Lake watershed in the event the regional board for the Lahontan region finds that with the export of toilet wastes by single-family residences or with the export of toilet and kitchen wastes with respect to any commercial properties, the continued use of septic tanks, cesspools, or other means of waste disposal in such area or areas for the treatment and disposal of the remaining wastes, will not, individually or collectively, directly or indirectly, affect the quality of the waters of Lake Tahoe, and that the sewering of such area or areas would have a damaging effect upon the environment.

This section shall not affect the applicability of Section 13950. (Amended by Stats. 1975, Ch. 637.)

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§ 13952.[Pilot reclamation projects] Notwithstanding the provisions of Sections 13950 and 13951, water containing waste which has been placed in a sanitary sewer system for treatment and transportation outside of the Lake Tahoe Basin may be reclaimed in a pilot reclamation project to demonstrate the technological and environmental feasibility of using such water for beneficial purposes within the Lake Tahoe Basin in accordance with the provisions of the Water Reclamation Law (Chapter 7 (commencing with Section 13500) of this division) and the provisions of this section.

Prior to the initiation of any pilot reclamation project within the Lake Tahoe Basin, the reclaimer or reuser shall submit the project with technical data to the regional board for the Lahontan region for approval. Only those projects submitted before January 1, 1984, shall be considered. The technical data submitted shall demonstrate that such pilot reclamation project will not, individually or collectively, directly or indirectly, adversely affect the quality of the waters of Lake Tahoe. The intended operational life of the project shall be at least 10 years.

No pilot reclamation project shall be initiated unless and until such regional board approves the project, and finds that such pilot reclamation project or projects will not, individually or collectively, directly or indirectly, adversely affect the quality of the waters of Lake Tahoe. The regional board for the Lahontan region shall place conditions on any approved 118 California State Water Resources Control Board Porter-Cologne Act and Related Water Code Sections (January 2016) project to include specification of maximum project size. The regional board for the Lahontan region may suspend or terminate an approved project for cause at any time. (Added by Stats. 1978, Ch. 682.)

§ 13952.1. [South Tahoe Public Utility District; Luther Pass]

(a) Notwithstanding Section 13951, the South Tahoe Public Utility District may provide recycled water only to prevent the destruction of its Luther Pass recycled water pump station from a catastrophic fire if all of the following conditions are met:

(1) The district submits an engineering report to the Lahontan Regional Board and the State Department of Public Health, as required by that regional board and that department.

(2) The Lahontan Regional Board, the State Department of Public Health, and the Tahoe Regional Planning Agency authorize the use of recycled water, and the specified area or areas in the immediate vicinity of the pump station where that recycled water may be used, only to prevent the destruction of the district’s Luther Pass recycled water pump station from a catastrophic fire.

(3) The fire incident commander authorizes the use of the recycled water to prevent the destruction of the district’s Luther Pass recycled water pump station from a catastrophic fire, as authorized pursuant to this section.

(b) For purposes of this section, “catastrophic fire” means a condition exists that will result in severe harm to life, property, and the environment if the use of recycled water as authorized pursuant to this

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section is not used, and all other methods to extinguish the fire have been exhausted. (Amended by Stats. 2010, Ch. 288, Sec. 57. Effective January 1, 2011.)

§ 13952.5. [Waste discharge requirements]

The declared statewide interest in the preservation of Lake Tahoe, and the state and federal actions mandating the transportation of treated sewage effluent out of the Lake Tahoe watershed, requires that the law relating to the authority for prescribing waste discharge requirements for the effluent, and requirements pertaining to the storage of the effluent, the receiving waters, and the disposal areas, be clarified, and that law is hereby clarified and confirmed, to provide that, notwithstanding Section 13002 or any other provision of law, the regional board for the Lahontan region has exclusive authority to prescribe, under existing law, waste discharge requirements for treated sewage effluent transported out of the Lake Tahoe watershed to Alpine County within the Lahontan region, including requirements pertaining to the storage of the effluent, the receiving waters, and the disposal areas in Alpine County within the Lahontan region. However, any such action by that regional board is subject to review as provided in Sections 13320 and 13330. (Added by Stats. 1985, Ch. 447, Sec. 1.)

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5.8 WASTEWATER TREATMENT, EXPORT, AND DISPOSAL

The Porter-Cologne Act (§ 13950-13952) includes specific language regarding domestic wastewater disposal in the Lake Tahoe Basin. It requires the export of all domestic wastewater from the California portion of the Lake Tahoe Basin; an Executive Order of the Governor of Nevada requires export on the Nevada side. The TRPA also prohibits the discharge of domestic, municipal, or industrial wastewater within its jurisdiction, with the types of exceptions noted below.

Under the Porter-Cologne Act, the Regional Board allows exceptions to the mandate for export for a small number of summer homes in remote areas of the Lake Tahoe Basin where sewering would be environmentally damaging. Toilet wastes must be disposed to holding tanks, or incinerator toilets; holding tank wastes or ashes must be exported from the Lake Tahoe Basin (see the discussion of septage disposal in Chapter 4). Disposal of graywater (sink and shower wastes only) to leachfields may be allowed. Food wastes must be exported or incinerated. Garbage grinders, washing machines, dishwashers, and phosphate-based detergents are not allowed. Proper long-term maintenance of exempted facilities (both holding tanks and greywater systems) is very important. Regional Board staff should continue surveillance of these exempted facilities, and their exemptions should be revoked if the Regional Board cannot continue to find that they will not individually or collectively, directly or indirectly, adversely affect the quality of the waters of Lake Tahoe. The Forest Service periodically reviews its permits for summer home tracts. Regional Board staff should continue to review and comment on proposals for permit extensions, to ensure that wastewater issues are adequately addressed. The Regional Board shall make sure that the conditions of exemptions are complied with before extending the exemptions for septic system discharges. The Regional Board will also reconsider the exemptions in the light of technical advances permitting installation of low pressure sewers in environmentally sensitive areas.

Proper disposal of domestic wastewater from holding tanks and chemical toilets in boats and recreational vehicles is an issue of concern in the Lake Tahoe Basin. See the discussions of control measures for campgrounds and day use areas, and for impacts of

boating recreation in the section of this Chapter on recreational impacts, below.

Occasionally, existing structures in more urbanized areas of the Lake Tahoe Basin are found not to be connected to a sewer system. Wastewater collection and treatment agencies should continue to review records and use appropriate field methods to survey for unconnected wastewater discharges within their jurisdictions, and should inform Regional Board staff when such discharges are found. Where necessary, the Regional Board may use enforcement action to prevent discharges from unconnected structures. The Tahoe Regional Planning Agency requires all projects involving a new structure, or reconstruction or expansion of an existing structure, which is designed or intended for human occupancy, and which generates wastewater, to be served by facilities for the treatment and export of wastewater from the Lake Tahoe Basin. To be considered served, a service connection shall be required to transport wastewater from the parcel to a treatment plant.

The Porter-Cologne Act (§ 13952) allows the Regional Board to consider approval of pilot reclamation projects for the use of reclaimed domestic wastewater for beneficial purposes within the Lake Tahoe Basin, provided that such projects will not individually or collectively, directly or indirectly, adversely affect the quality of the waters of Lake Tahoe. The Regional Board shall place conditions on any approved project to include specification of maximum project size. The Regional Board may suspend or terminate an approved project for cause at any time.

In order to prevent raw sewage overflows, all sewerage agencies within the Lake Tahoe Basin are required to have preventative maintenance and spill response programs; enforcement actions may be taken if spills occur. Enforcement orders and grant conditions will require measures such as installation of monitoring equipment and any necessary reconstruction or relocation of sewerlines.

The Regional Board should continue to incorporate requirements for preventative maintenance and spill response programs into waste discharge requirements and National Pollutant Discharge Elimination System (NPDES) permits for all wastewater treatment agencies in the California portion of the Lake Tahoe Basin. These could include requirements for the installation of monitoring equipment, or for the reconstruction or relocation of defective sewerlines. If a sewerline has a series of overflows due to design deficiencies, it should be reconstructed. Bolted down, sealed manhole covers

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should be added to sewerlines that parallel the Lake Tahoe shoreline or are located in SEZs to prevent spills from exiting via loose manhole covers. In other areas, sewerlines in or adjacent to stream channels should be relocated to high ground and fitted with sealed manhole covers.

Grants, NPDES permits, and waste discharge requirements for wastewater collection and treatment facilities serving the Lake Tahoe Basin should be conditioned to prohibit the sewerage agencies from providing any connection serving new development which is not in accordance with this Basin Plan. This includes development which is not in compliance with the waste discharge prohibitions discussed in section 5.2 of this Chapter. State and federal buyout programs for sensitive lots include payment of wastewater treatment plant assessments for lots which cannot be built upon without violation of these prohibitions. The Regional Board shall require that the necessary information be submitted in reports of waste discharge to determine whether applications are consistent with the waste discharge prohibitions.

Due to aging infrastructure, the likelihood of exfiltration problems in the Tahoe Basin sewer systems may have increased since the early 1980s. Further study of all potential sources of nitrogen in Tahoe Basin ground water should be encouraged as part of the ongoing interagency monitoring program. Waste discharge requirements could be used to require correction of sewer exfiltration problems if such problems are shown to be significant in the future. Proposals for study and correction of exfiltration problems could be eligible for grant funding.

Waste discharge requirements for Tahoe Basin sewerage agencies should include a requirement that these agencies submit annual reports providing information needed to update estimates of available capacity, including information on flows, connections during the past year, and remaining unused treatment plant capacity.

The three sewerage agencies on the California side of the Lake Tahoe Basin also function as water purveyors. The State Board has directed that waste discharge requirements for these agencies should include conditions designed to prevent water use in the basin beyond the limits of the California-Nevada Interstate Water Compact (portions of this Compact which deal with the Lake Tahoe Basin were ratified by Congress in 1990 as PL 101-618).

The South Tahoe Public Utility District (STPUD) provides wastewater collection and treatment for the southern part of the Tahoe Basin in California, and

exports treated effluent to Alpine County, where it is stored and used for pasture irrigation. The North Tahoe Public Utility District (NTPUD) and Tahoe City Public Utility District (TCPUD) operate collection systems and export sewage for treatment and disposal by the regional Tahoe-Truckee Sanitation Agency (TTSA), located in Truckee in Nevada County. Chapter 4 of this Basin Plan contains additional information on the STPUD and TTSA facilities, including their operations outside of the Lake Tahoe Basin. The following is a summary of important issues related to these facilities and to the Tahoe Basin implementation program.

South Tahoe Public Utility District

The South Tahoe Public Utility District (STPUD) provides collection and treatment for municipal wastewater from most of the El Dorado County portion of the Lake Tahoe Basin. Wastewater is given advanced secondary treatment and pumped over Luther Pass to the East Fork Carson River in Alpine County, where it is stored in Harvey Place Reservoir and used for pasture irrigation.

Tahoe-Truckee Sanitation Agency

The regional wastewater treatment facilities of the Tahoe-Truckee Sanitation Agency (TTSA), located in Truckee in Nevada County, provide tertiary treatment for wastewater collected by the North Tahoe and Tahoe City Public Utility Districts in the Lake Tahoe Basin. (TTSA also serves other member districts outside of the Lake Tahoe Basin.) Wastewater is carried from member districts by an interceptor pipeline which generally parallels the Truckee River. TTSA's member districts formerly operated separate wastewater treatment plants but now operate and maintain collection facilities. Discharge prohibitions for the Truckee River Hydrologic Unit (HU), cited in the prohibition section of this Chapter, include prohibitions affecting further operation of these treatment plants, and discharges from septic tank/leachfield systems from current and future development in the portion of the HU within TRPA's jurisdiction. Additional information on TTSA's treatment and disposal operations in relation to water quality in the Truckee River HU is provided in Chapter 4 of this Basin Plan.

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5.9 WATER RIGHTS AND WATER USE

In 1988, there were approximately 57 water purveyors providing domestic supplies to development within the California portion of the Lake Tahoe Basin.

There were about 17 suppliers in California using over 100 acre-feet per annum (afa4). Water supplies are obtained from public and private wells, intakes from Lake Tahoe, and surface water diversions from tributaries. In the past, some water purveyors did not always treat well water prior to distribution, although chlorination might be provided at certain times of the year. Drinking water from surface intakes, both from streams and Lake Tahoe, has historically been filtered and chlorinated prior to distribution. New federal drinking water regulations require higher treatment levels for surface sources; because of these regulations, water purveyors are increasingly changing from surface to ground water sources.

Total water diversion for consumptive use in the Lake Tahoe Basin is limited by the California-Nevada Interstate Water Compact, an agreement which, after 13 years of negotiation, was ratified by the legislatures of both states in 1970 and 1971, and partly ratified by Congress in 1990 as P.L. 101-618. On the California side of the Lake Tahoe Basin, total diversions for consumptive use from all sources (both surface and ground waters) are limited to 23,000 afa.

The State Water Resources Control Board, which is responsible for administering California's water rights program, issued a Report on Water Use and Water Rights in the Lake Tahoe Basin in January 1980. The report determined that after water rights held by the USFS, State Parks requirements, and certain exports and depletions are taken into account, 19,000 afa is available for use on private lands on the California side of the Basin. The report also estimated the amount of water used at different levels of projected development.

The State Board has adopted a policy of limiting new water rights permits in accordance with the Compact allocation. The State Board does not have permit authority over all diversions, however. The largest group of diversions not subject to permit is ground water diversions, which made up 54% of the total diversions for use on the California side of the Lake Tahoe Basin in 1980. Local government has authority to regulate ground water pumping, and special ground water districts can be created, but current State law does not require local government

to act, even when ground water pumping exceeds available supply.

The water rights study recommended that the State Board issue new water rights permits subject to conditions which ensure that issuance of the permits will not result in use in excess of the amount available under the Interstate Water Compact. It further recommended that water available for use on private lands be allocated among three zones corresponding to the boundaries of the North Tahoe, Tahoe City, and South Tahoe Public Utility Districts. Water rights permits would be issued to the utilities, allowing them to divert amounts equal to the amount allocated to the zone minus the total of all other diversions, including ground water diversions, for use on private lands within the zone.

Current levels of consumptive water use in the Lake Tahoe Basin are unknown. (Most water use is not metered.) State law (AB 2572) enacted in 2004 requires all water suppliers to install water meters on all customer connections by January 1, 2025.New residential construction has occurred since 1982, but conservation efforts (e.g., landscape watering restrictions and requirements for ultra-low flow toilets) have increased due to drought conditions. As of 2010 there are fewer than 5000 private, undeveloped, potentially buildable parcels throughout all jurisdictions in the Lake Tahoe Basin. At the highest rate of residential building allowed by TRPA, 294 building allocations per year, these parcels could be built in 16 years.

The State Board's water rights report recommends that local and regional agencies involved in land use planning consider the limitations set by the Interstate Water Compact, and that the State's water quality program take the availability of water into account. The California Water Code directs the State and Regional Boards to take water supply into account during water quality planning, and in issuing waste discharge requirements. The public utility districts provide sewerage service, for which they are subject to waste discharge requirements issued by the Lahontan Regional Board. Any additional development in the Lake Tahoe Basin which will increase water use will not be possible without a connection to the sewerage system. The number of units which may connect to the sewerage systems is limited by sewage collection, treatment, and disposal capacity. Accordingly, this Basin Plan requires that waste discharge requirements issued for these sewerage systems include conditions designed to prevent water use in the Lake Tahoe Basin beyond the Compact limitations. The conditions could take several different forms, ranging from connection limitations to water conservation programs. The

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precise form the conditions shall take will be determined when waste discharge requirements are renewed or modified.

TRPA requires all projects proposing a new structure, or reconstruction or expansion of an existing structure designed or intended for human occupancy to have adequate water rights or water supply systems. TRPA cannot approve additional development requiring water unless it has, or provides, an adequate water supply within a water right recognized under state law.

TRPA recognizes that many water supply systems are in need of upgrading to insure delivery of adequate quantities of water for domestic and fire suppression purposes. Needed improvements include water lines, storage facilities, and additional hydrants. TRPA requires all additional development requiring water to have systems to deliver an adequate quantity and quality of water for domestic consumption and fire protection. Applicable local, state, federal, or utility district standards determine adequate fire flows, but where no such standards exist, the TRPA Code of Ordinances provides minimum fire flow requirements. TRPA may waive the fire flow requirements for its plan areas which are “zoned” for conservation and recreation uses, and for single family development if fire departments serving the development meet the requirements of the TRPA Code. Individual water suppliers will have to maintain their existing water supply systems, and upgrade them as appropriate to meet fire flow requirements, peak demand, and the need for backup supplies. Water suppliers will also have to provide treatment for drinking water from surface diversions in accordance with state and federal standards and regulations.

This Basin Plan provides exemptions from discharge prohibitions for public health and safety projects, including projects associated with domestic water supply systems. As noted above, new treatment requirements are leading to an increase in ground water diversions. New wells in SEZs may affect SEZ functions both through direct disturbance for construction of wells and distribution lines, and through the impacts of ground water drawdown on SEZ soils and vegetation. When considering exemptions from discharge prohibitions for new or expanded ground water diversions in SEZs, the Regional Board should evaluate the water quality impacts and “reasonableness” of these projects in relation to those of the alternative of continued use of a surface source, even if treatment costs are higher.

The remedial erosion control projects proposed in this Chapter require use of irrigation water for

revegetation. However, native plants will be used except for some temporary stabilization, and once established will not require irrigation. To ensure that the irrigation needed for revegetation can be carried out within the limits of water supply, the State Board's water rights decisions should reserve water for revegetation. Once it is determined that reserving water for revegetation is no longer necessary, the water can be made available for municipal and domestic use.

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APPENDIX - C. DEFINITIONS FOR PURPOSES OF THIS LAMP: “303(d) List” means the same as “Impaired Water Bodies.” “State OWTS Policy”" or Policy means the OWTS Policy (Water Quality Control Policy for Siting, Design, Operation, and Maintenance of Onsite Wastewater Treatment Systems) adopted by the State Water Resources Control Board requiring the preparation of a Local Agency Management Plan (LAMP). “Alternate Dispersal Systems” include shallow trench pressure distribution, mound, At-Grade System, drip dispersal, and other alternative Dispersal Systems approved by the Director. Some Alternate Dispersal Systems can be used without the need for a Supplemental Treatment system. “At-Grade System” means an OWTS dispersal system with a discharge point located at the preconstruction grade (ground surface elevation) with qualifying fill material used to cover the Dispersal System. The discharge point of an At-Grade System is, therefore, always subsurface. “Average Annual Rainfall” means the average annual amount of precipitation for a location over a year as measured by the nearest National Weather Service station for the preceding three decades. For example, the data set used to make a determination in 2015 would use the data from 1984 to 2013. “Basin Plan” means the same as “water quality control plan” as defined in Division 7 (commencing with Section 13000) of the Water Code. Basin Plans are adopted by each Regional Water Board, approved by the State Water Board and the Office of Administrative Law, and identify surface water and groundwater bodies within each Region’s boundaries and establish, for each, its respective beneficial uses and water quality objectives. The Tahoe Basin Plan can be found in California Health & Safety Code sections 13950 to 13952.5. “Biomat” is a bacterial slime layer which forms in soil at the bottom of leach lines and other Dispersal Systems. It is responsible for much of the treatment and reduction of biological solids and bacteria present in onsite wastewater treatment system Effluent (from either a septic tank or Supplemental Treatment system) discharged to the soil. “CEDEN” means California Environmental Data Exchange Network and information about it is available at the State Water Boards website or http://www.ccden.org/index.shtml. “Cesspool” means an excavation in the ground receiving domestic wastewater, designed to retain the organic matter and solids, while allowing the liquids to seep into the soil. Cesspools differ from seepage pits because cesspool systems do not have septic tanks and are not authorized under this LAMP. The term cesspool does not include pit-privies and out-houses which are not regulated under this LAMP. “Chroma” is a measure of color purity in the Munsell color system. “Clay” means a soil particle; the term also refers to a type of soil texture. As a soil particle, clay consists of individual rock or mineral particles in soils having diameters <0.002 mm. As a soil texture, clay is the soil material that is comprised of 40 percent or more clay particles, not more than 45 percent sand and not more than 40 percent silt particles using the USDA soil classification system.

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“Cobbles” means rock fragments 76 mm or larger using the USDA soil classification system. “Curtain drain or French drain” is a gravel trench that is excavated down to a relatively impermeable soil layer and installed to intercept, collect, and remove shallow subsurface groundwater as it flows above the impermeable layer. “Cut” means any altered area of land surface having a distinctly greater slope than the adjacent ground surface, over 24 inches in vertical height or the OWTS Dispersal System backfill cover depth, whichever is greater, and any part of which is lower in elevation than the ground surface at the nearest point of the OWTS. Cuts supplied by retaining walls or other similar structures shall be included in this definition, as shall be steep natural ground surfaces where a sharp break in the ground slope is discernable. “Director” means the Division Director of Environmental Management or his/her designee in the El Dorado County Environmental Management Division of the Community Development Agency. “Dispersal system” means a leachfield, seepage pit, mound, at-grade, subsurface drip field, evapotranspiration and infiltration bed, or other type of system for final wastewater treatment and subsurface discharge. “Domestic Wastewater” means wastewater with a measured strength less than high-strength wastewater and is the type of wastewater normally discharged from, or similar to that discharged from, plumbing fixtures, appliances, and other household devices including, but not limited to toilets, bathtubs, showers, laundry facilities, dishwashing facilities, and garbage disposals. Domestic wastewater may include wastewater from commercial buildings, such as office buildings, retail stores, and some restaurants, or from industrial facilities where the Domestic Wastewater is segregated from the industrial wastewater. Domestic Wastewater does not include industrial wastewater or wastewater consisting of a significant portion of RV holding tank wastewater such as at RV Dump Stations. “Domestic Well” means a groundwater well that provides water for human consumption and is not regulated by the California Department of Public Health. “Dump Station” means a facility intended to receive the discharge of wastewater from a holding tank installed on a recreational vehicle. A Dump Station does not include a full hook-up sewer connection similar to those used at a recreational vehicle park. “Earthen material” means a substance composed of the earth’s crust (i.e. soil and rock). “EDF” or “Electronic Deliverable Format” means the data standard adopted by the State Water Board for submittal of groundwater quality monitoring data to the State Water Board’s internet accessible database system GEOTRACKER (http://geotracker.waterboards.ca.gov). “Effluent” means sewage, water, or other liquid, partially or completely treated or in its natural state, flowing out of a septic tank, aerobic treatment unit, Dispersal System, or other OWTS component. “Engineered fill” means a designed placement of specified imported soil over existing native soils on an existing parcel with inadequate soil depth to meet the minimum two (2) to three (3) feet of soil depth required beneath a Dispersal System and a minimum of two (2) to three (3) feet of separation between the bottom of a Dispersal System and a water table.

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“Ephemeral Stream” means a stream, or other drainage such as a roadside ditch, that flows for less than five (5) days after the passage of a storm. An ephemeral stream only carries water in direct response to a precipitation event and it contains no water from a spring, snow, or other long-continuing surface source and does not discharge to a perennial aquifer. Setback measurements are made from the edge of the channel. “Existing OWTS” means an OWTS in which a valid construction permit has been issued or that was constructed and operated prior to the effective date of this LAMP. “Existing Parcel” means any vacant or developed parcel that was in existence prior to effective date of this LAMP. “Failure” means the ineffective dispersal of waste resulting in the surfacing of sewage or inadequately treated sewage Effluent and/or the degradation of surface or groundwater quality. “GeoTracker” is the SWRCB data management system for managing sites that impact groundwater, especially those that require groundwater cleanup. “Gleyed soils” are soils developed under conditions of poor drainage and can generally be found as surface water and ground water gleys. “Groundwater” means water that is below the land surface that is at or above atmospheric pressure. "High-strength wastewater" means wastewater having a 30-day average concentration of biochemical oxygen demand (BOD) greater than 300 milligrams-per-liter (mg/L) or of total suspended solids (TSS) greater than 330 mg/L or a fats, oil, and grease (FOG) concentration greater than 100 mg/L prior to the septic tank or other OWTS treatment component. “Holding Tank” means a watertight receptacle used to collect and store wastewater prior to it being removed from a property by means of vacuum pumping and hauling or another approved method.

“IAPMO” means the International Association of Plumbing and Mechanical Officials. “Impaired water bodies” means those surface water bodies or segments thereof that are identified on a list approved first by the State Water Board and then approved by the U.S. EPA pursuant to Section 303(d) of the federal Clean Water Act. “Intermittent sand filter” means a packed-bed filter of medium-grained sand used to treat septic tank Effluent to an advanced level. Wastewater is dosed to the surface of the sand through a pressure-distribution network and allowed to percolate through the sand where BOD is reduced and suspended solids are removed; treatment is accomplished by physical filtration as well as microbial growth on the surface of the sand grains. After a single pass, the Effluent is collected in an underdrain system for further processing or dispersal.

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“Irrigation ditch or canal” means a man-made lined or unlined ditch intended to supply dry land with water and must meet the setbacks specified for ephemeral, intermittent, or seasonal Drainage Ways except as allowed otherwise. “Local Agency Management Plan” or “LAMP” means this document to be used for siting, evaluation, design, operation, and management of onsite wastewater systems within El Dorado County, in conjunction with El Dorado County Ordinance Chapter 110.32 and the OWTS Manual. “Major repair” means either (1) for a dispersal system, repairs required for an OWTS dispersal system due to surfacing wastewater Effluent from the dispersal field and/or wastewater backed up into plumbing fixtures because the dispersal system is not able to percolate the design flow of wastewater associated with the structure served; or (2) for a septic tank, repairs required to the tank for a compartment baffle failure or tank structural integrity failure such that either wastewater is exiting or groundwater is infiltrating. “Minor repair” means a failure of a component other than a septic tank, treatment system, or dispersal system such as a distribution box or broken piping connection. "Mottles" means a soil condition that results from oxidizing or reducing minerals due to soil moisture changes from saturated to unsaturated over time. Mottling is characterized by spots or blotches of different colors or shades of color (grays and reds) interspersed within the dominant color as described by the USDA soil classification system. The soil condition can be indicative of historic seasonal high groundwater level, but the lack of this condition may not demonstrate the absence of groundwater. “New OWTS” means an OWTS permitted after the effective date of this LAMP. “NSF” means NSF International (a.k.a. National Sanitation Foundation), a not for profit, non-governmental organization that develops health and safety standards and performs product certification. “Onsite wastewater treatment system(s)” or “OWTS” means individual treatment and dispersal systems, community treatment and dispersal systems, and alterative treatment and dispersal systems that collect and treat wastewater for subsurface dispersal. The short form of the term may be singular or plural. OWTS do not include “gray water” systems pursuant to Health and Safety Code section 17922.12. “Perennial Waterway” is a stream or other drainage which has continuous flow in all or parts of its stream bed all year during normal rainfall years but may flow only intermittently in drought years. “Percolation test” means a method of testing the water absorption ability of the soil. The test is conducted with clean water and test results are used to establish a percolation rate and facilitate the dispersal system sizing and design. “Permeable soil” means soil that has a percolation rate of 120 minutes per inch or faster or having a clay content of less than 60 percent and does not contain solid rock formations or rock formations that contain continuous channels, cracks, or fractures. “Permit” means a written document issued by CDAEMD that allows the construction, installation, use, repair, expansion, replacement, or destruction of an existing OWTS or any part thereof.

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“Pollutant” means any substance that alters the waters of the State to a degree that it may potentially affect the beneficial uses of water, as listed in, but not limited to, a Basin Plan. “Portable Toilet” means an enclosed unit intended for temporary use at a given location. Portable Toilets may also be referred to as “chemical toilets” in other county ordinances or California statutes or regulations. "Precipitation" means measureable amounts of rain, snow, hail, and other similar natural phenomenon. “Projected flow” means wastewater flows into the OWTS determined in accordance with any applicable methods for determining average daily flow as approved by the Director. “Public Water System” is a water system regulated by the California Department of Public Health or a Local Primacy Agency pursuant to Chapter 12, Part 4, California Safe Drinking Water Act, Section 116275 (h) of the California Health and Safety Code. “Public Water Well” is a ground water well serving a Public Water System. A spring which is not subject to the California Surface Water Treatment Rule (SWTR), CCR, Title22, and Sections 64650 through 64666 is to be considered a public water well. “Qualified Professional” means an individual licensed or certified by a State of California agency to design OWTS and practice as professionals for other associated reports, as allowed under their license or registration. Depending on the work to be performed and various licensing and registration requirements, this may include an individual who possesses a registered environmental health specialist certificate or is currently licensed as a professional engineer or professional geologist. For the purposes of performing site evaluations, Soil Scientists certified by the Soil Science Society of America are considered Qualified Professionals. Qualified Professionals must have the education and experience necessary to conduct onsite surveys for OWTS suitability, evaluate potential pathways of wastewater-sourced phosphate and other nutrients toward potentially threatened nearby wells or surface bodies of water, consider hydraulic mounding and linear loading at the site, complete all necessary soils tests, prepare system designs and drawings, meet with owners and installers, and conduct necessary inspections. No other person, license, or registration/certification will be approved as a Qualified Professional. “Replacement Area” or “Repair Area” means an area that is one hundred (100) percent in size of the area approved for the initial sewage system disposal field for a residence and three hundred (300) percent in size of the area approved for the initial sewage system disposal field for others. “Replacement OWTS” means an OWTS that has its treatment capacity expanded, or its dispersal system replaced or otherwise added onto, after the effective date of this LAMP. An OWTS may be replaced for a variety of reasons including failure, home additions increasing the number of occupants/water use, relocation to accommodate home additions, home sales, and other reasons. “Sand” means a soil particle; this term also refers to a soil texture. As a soil particle, sand consists of individual rock or mineral particles in soil having diameters ranging from 0.05 mm to 2.0 mm. As a soil texture, sand is soil that is comprised of 85 percent or more sand particles, with the percentage of silt plus 1.5 times the percentage of clay particles comprising less than 15 percent.

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“Seepage pit” means a vertical excavation constructed to receive Effluent from a septic tank. As the adopted State OWTS Policy requires a minimum of ten (10) feet of adequate soil and separation between the bottom of the pit and highest anticipated groundwater level and increased horizontal separation distances, it is not anticipated that permits will be issued for their construction and use in El Dorado County. “Septic tank” means a water tight, covered receptacle designed for primary treatment of wastewater and constructed to:

1. Receive wastewater discharged from a building or other use; 2. Separate settleable and floating solids from the liquid; 3. Digest organic matter by anaerobic bacterial action; 4. Store undigested solids; and 5. Clarify wastewater for further treatment/subsurface discharge.

“Service Provider” means a person capable of operating, monitoring, and maintaining an OWTS in accordance with this LAMP. “Site” means the location of the OWTS and, where applicable, a reserve dispersal area capable of disposing of 100 percent of the design flow from all sources the OWTS is intended to serve. “Site Evaluation” means an assessment of the characteristics of the site and onsite soils sufficient to determine suitability for an OWTS to meet the requirements of this Policy. “Site Plan” means a site plot plan showing all details required under this LAMP, including all existing topographic features, the locations of all required soil tests, and all proposed site grading, structures and other existing/planned improvements. “Slope” means the rise or fall of vertical elevation in feet, per one hundred (100) feet of horizontal distance. Slope is expressed as a percent of grade. For example, a rise of 30 feet in a 100 foot run is a 30 percent slope. A rise of 40 feet in a 100 foot run is a slope of 40 percent. “Soil” means the naturally occurring body of porous mineral and organic materials on and at the land surface, which is composed of unconsolidated materials, including sand-sized, silt-sized, and clay-sized particles mixed with varying amounts of larger fragments and organic material. The various combinations of particles differentiate specific soil textures identified in the soil textural triangle developed by the United States Department of Agriculture (USDA) as found in Soil Survey Staff, USDA; Soil Survey Manual, Handbook 18, U. S. Government Printing Office, Washington, DC, 1993, p. 138. For purposes of this LAMP, soil shall contain earthen material of particles smaller than 0.08 inches (2mm) in size. For the purposes of this LAMP, soil is the ultimate receiver of wastewater and the most important part of an OWTS. Therefore, in addition to the depth to groundwater, the proper evaluation of soil structure, permeability, and overall useable soil depth is critical in the proper choice and design of an OWTS for any particular site. “Soil Profile” is a natural sequence of layers, or horizons, in the soil as described in a suitable manner acceptable to CDAEMD.

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“Soil Structure” means the arrangement of primary soil particles into compound particles, peds, or clusters that are separated by natural planes of weakness from adjoining aggregates. “Soil Texture” means the soil class that describes the relative amount of sand, silt, and clay and combinations thereof as defined by the classes of the soil textural triangle developed by the USDA. “Special Design OWTS” is an OWTS that does not meet the criteria for a Tier 1 Standard OWTS. “Standard Onsite Wastewater Treatment System” means an OWTS constructed in soil meeting Tier 1 specifications. A Standard OWTS consists of a septic tank and a series of subsurface dispersal trenches for subsurface dispersal of Effluent into the soil. A Standard OWTS may utilize gravity flow or a pump system to convey Effluent from the septic tank to the drain field. “Substandard System” means any Existing OWTS that does not conform to the system sizing, setbacks, soil depth, or groundwater separation requirements of this LAMP. “Supplemental Treatment” means any OWTS or component of an OWTS, except for a septic tank or dosing tank, that performs additional wastewater treatment using intermittent and recirculating sand filters, proprietary treatment units, and other alternative treatment systems approved by the Director, so that the Effluent meets a predetermined performance requirement prior to discharge of the Effluent into the dispersal field. Some Supplemental Treatment units are passive and can be placed directly onto a leach bed for direct dispersal into the soil. “SWAMP” means Surface Water Ambient Monitoring Program and more information is available at http://www.waterboards.ca.gov/water issues/programs/swamp/. “TMDL” is the acronym for “total maximum daily load.” Section 303(d)(l) of the Clean Water Act requires each state to establish a TMDL for each impaired water body to address the pollutant(s) causing the impairment. In California, TMDL’s are usually adopted as Basin Plan amendments and contain implementation plans detailing how water quality standards will be attained. “USDA” means the U.S. Department of Agriculture. “Waste Discharge Requirement” or “WDR” means an operation and discharge permit issued for the discharge of waste (including OWTS Effluent) pursuant to Section 13260 of the California Water Code.

http://www.waterboards.ca.gov/water

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STANDARDS FOR THE SITE EVALUATION, DESIGN AND CONSTRUCTION OF ONSITE WASTEWATER TREATMENT SYSTEMS (OWTS MANUAL) Effective May 13, 2018

CONTENTS INTRODUCTION ........................................................................................................................... 1

SECTION 1 – GENERAL PROVISIONS ...................................................................................... 1

SECTION 1A. SITE EVALUATION ....................................................................................... 1

SECTION 1B. OWTS SITE EVALUATION REPORT AND SITE PLANS .......................... 7

SECTION 1C. PARCEL CREATION ....................................................................................... 9

SECTION 1D. MINIMUM PARCEL SIZE ............................................................................ 10

SECTION 1E. REVISIONS .................................................................................................... 10

SECTION 1F. APPLICATION PROCESS ............................................................................. 10

SECTION 1G. INSPECTIONS ............................................................................................... 11

SECTION 1H. PROHIBITIONS ............................................................................................. 12

SECTION 1I. ENFORCEMENT ............................................................................................. 12

SECTION 2 – DESIGN PROCEDURES ...................................................................................... 14

SECTION 2A. GENERAL REQUIREMENTS ...................................................................... 14

SECTION 2B. SETBACKS ..................................................................................................... 18

SECTION 2C. SPECIAL DESIGN OWTS ............................................................................. 20

SECTION 2D. SUPPLEMENTAL TREATMENT OWTS .................................................... 28

SECTION 2E. OPERATING PERMITS ................................................................................. 29

SECTION 3 – MATERIALS, CONTRUCTION, AND INSTALLATION ................................. 31

SECTION 3A. SEPTIC TANK ............................................................................................... 31

SECTION 3B. SERIAL DISTRIBUTION MATERIALS AND CONSTRUCTION ............. 32

SECTION 3C. EFFLUENT PUMP, CONTROL, AND ALARM MATERIALS ................... 33

SECTION 3D. PIPING MATERIALS AND CONTRUCTION ............................................. 33

SECTION 3E. OWTS WITH A CURTAIN DRAIN .............................................................. 34

SECTION 3F. DISPOSAL FIELD INSTALLATION AND MONITORING ........................ 36

SECTION 3G. COMMERCIAL OR INDUSTRIAL SPECIAL LIQUID WASTE DISPOSAL ....................................................................................................................................... 37

SECTION 3H. CESSPOOLS AND HOLDING TANKS ........................................................ 37

SECTION 3I. PORTABLE AND VAULT TOILETS ............................................................ 38

SECTION 4 - REPAIR OR ADDITIONS TO EXISTING OWTS .............................................. 38

SECTION 4A. COMPLAINT INVESTIGATION PROCEDURES – NOTIFICATION OF FAILURE ...................................................................................................................... 38

SECTION 4B. REPAIR CRITERIA ....................................................................................... 40

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SECTION 4C. DESIGN FOR SINGLE FAMILY DWELLINGS .......................................... 40

SECTION 4D. SMALL PARCELS AND LIMITED AREA FOR REPAIR .......................... 40

SECTION 4E. REPAIRS FOR COMMERCIAL PROPERTIES ............................................ 40

SECTION 4F. REPAIRS USING PUMP SYSTEMS ............................................................. 41

SECTION 4G. ABANDONED SEWERS AND WASTEWATER DISPOSAL FACILITIES 41

SECTION 4H. REPORTING TO OWNERS OF PUBLIC WATER SYSTEMS AND DIVISION OF DRINKING WATER AT THE SWRCB ............................................. 41

SECTION 5 – DEFINITIONS ...................................................................................................... 42

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INTRODUCTION The County of El Dorado, Community Development Agency, Environmental Management Division (CDAEMD) is responsible for protecting public health and the environment from the potential adverse health and environmental impacts associated with Onsite Wastewater Treatment Systems (OWTS). This responsibility is carried out through the review of OWTS design proposals, review of design criteria, and inspection of construction of new, and repair of existing, OWTS to determine conformance with applicable codes. The Standards for the Site Evaluation, Design and Construction of OWTS (OWTS Manual) has been prepared in conjunction with El Dorado County’s Local Agency Management Plan (LAMP) to meet the California State Water Resources Control Board OWTS Policy (State OWTS Policy) dated June 19, 2012.

SECTION 1 – GENERAL PROVISIONS SECTION 1A. SITE EVALUATION Purpose of Site Evaluation The purpose of the site evaluation is to determine whether or not a parcel can accommodate an OWTS. The site evaluation is used to determine soil depths and Groundwater levels when siting and designing OWTS on existing parcels to accomplish the following:

• Protect Groundwater quality by ensuring proper treatment of the sewage Effluent prior to its entering into Groundwater;

• Protect the public health from Failing OWTS caused by high Groundwater; and • Provide a methodology for the evaluation of potential building sites using OWTS

with regard to maintaining minimum Groundwater separation requirements of the adopted State OWTS Policy and ensuring utilization of the most porous or absorptive portions of the soil formation consistent with this Manual.

A site evaluation, CDAEMD site approval, and an OWTS Permit are needed to install, repair, or change an OWTS. The site evaluation is the procedure in which the Qualified Professional and the CDAEMD staff meet at the property and evaluate the site’s ability to dispose of sewage during the initial evaluation using Soil Observation Pits. Once the site evaluation is completed, the Qualified Professional will prepare and submit to CDAEMD a site evaluation report. The site approval is separate from the OWTS construction Permit. The OWTS construction Permit application is the process for obtaining the Permit to work and generally is issued in conjunction with a building permit. Site Evaluation Process The site evaluation for OWTS includes soil test data (soil profile, percolation tests, Groundwater monitoring results, and/or soil boring logs) to determine the soil’s ability to treat and dispose of Wastewater. A site evaluation is required for all parcels that will be utilizing OWTS. Only a Qualified Professional may conduct the site evaluation. The Qualified Professional assists the property Owner in locating the appropriate OWTS on the

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parcel. The Qualified Professional must evaluate the data collected and prepare the site evaluation report.

The soil test data is required to determine the type of system proposed and may be modified depending on the site characteristics. Collection of soil test data is typically required when:

• There is no data available; • An existing parcel, created prior to test requirements for land divisions, is proposed

for development; • Grading or other soil disturbance has occurred in the previously tested/approved area; • The system is being shifted out of the previously tested/approved area; • An OWTS other than the type of system previously approved is being considered; or • An existing OWTS fails or is proposed for expansion and no previous soil test data is

available for the specific parcel.

Move On Notification Request for Site Evaluation The following information shall be on the Soil Observation Pit Move On Notification request:

• Date of the Soil Observation Pit; • Time Soil Observation Pit ready for inspection; • Assessor’s parcel number and map; • Parcel size; • Location map and driving directions; • Name of Owner/builder/buyer of property; • Name of Qualified Professional and contact phone number; • Name of excavator; and • Project description; i.e., single family residence, parcel split, subdivision, boundary

line adjustment, or commercial project.

The Qualified Professional shall notify CDAEMD of the time and date of the scheduled Soil Observation Pits using the Appointment Scheduler on the CDAEMD website. Site evaluations shall be scheduled between 9 a.m. and 4 p.m., Monday through Friday, and shall not be scheduled on recognized El Dorado County holidays.

CDAEMD may require that a parcel be tested for the presence of Groundwater during wet weather, before an OWTS site is approved, based on the presence of soil mottling or gleyed colors in the Soil Observation Pit and/or the presence of hydrophilic vegetation. This requirement may also be set based on historical soils information available for an area.

Soil Profile - Soil Observation Pits: A soil profile is logged using a Soil Observation Pit. The Soil Observation Pit(s) must be located in the proximate area of the proposed Wastewater Disposal Area and must be excavated on each lot. If needed, additional Soil Observation Pit(s) may be required to locate a suitable area for the OWTS, specifically in an area of potential Groundwater, shallow soils, or fractured Bedrock.

The soil profile shall be logged by a Qualified Professional. CDAEMD staff must be present to inspect Soil Observation Pit excavation, unless other arrangements have been made with CDAEMD.

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All Soil Observation Pit(s) and deep borings shall have soils described as follows:

• For each pit or deep boring identify the property Owner, pit/deep boring number, the Slope percent of the area of the pit/boring, the date logged, and the Qualified Professional logging the pit/boring;

• All pit or deep boring logs, including failing pits/borings, are to be submitted to CDAEMD for review; and

• Within each pit/boring, from the surface to bottom of the excavation, the following is to be provided for each horizon:

o Depth within the pit/boring; o Color(s); o Amount (by percent) and size of gravels; o Soil texture; o The number, size, and prominence of soil mottles, where present; o Soil structure; o Consistency; and o Boundary thickness between horizons.

Percolation Test Hole Procedures: The location of the percolation test holes should be evenly distributed horizontally in the proposed leaching area. A minimum of four (4) percolation tests representative of the dispersal area shall be conducted on each proposed dispersal area. Deep trench designs shall be tested at varying depths for proper evaluation of soil.

Depth of Percolation Test Holes: Percolation test-hole depth shall be representative of the proposed Dispersal System or one (1) foot for systems such as an at-grade or drip Dispersal System. For each lot of proposed land divisions, two to three tests are to be conducted at a depth of three (3) feet and the remainder at a depth of one (1) foot.

Conditions which may require percolation testing deeper than dispersal depth include: • Consolidated rock or suspected impervious soil layers beneath the site; • Slopes exceeding 30%; or • Other factors as might be determined by sound site evaluation practices.

Location of Percolation Test Holes: Percolation test holes shall be excavated in the area representing the proposed location of the Dispersal System or within an expected proposed Disposal Area of a proposed parcel to be created by a land division. Percolation tests shall be conducted in soils suitable for dispersal of Effluent that otherwise meet soil depth and Groundwater depth for the type of system proposed for construction. Test holes shall be representative of the dispersal area demonstrating site conditions throughout the entire OWTS or proposed sewage dispersal area (land divisions) with equal consideration of primary and reserve Dispersal Systems.

Identification of Percolation Test Holes: When specifically requested, locations are to be staked and flagged so the test-hole locations can be located. They are to be identified as to location on the site plan with:

• A test hole number or letter; • Depth of the test hole; and

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• Proposed lot/parcel number or letter if associated with a subdivision or other land use project requiring soil testing.

Percolation Test Holes shall be constructed as follows:

• Diameter of percolation test holes shall be a minimum of six (6) inches. If a shallow backhoe excavation is used, a percolation test hole at twelve (12) to fourteen (14) inches in depth shall be excavated into the bottom of the backhoe bucket trench (the bottom of the percolation hole within this trench is to be at the percolation test-hole depth required for the project);

• Scarify the sides and bottom of the holes, as needed, to remove the soil surface areas that became smeared by the auger or other tool used to excavate the hole;

• Remove as much loose material as possible from the hole; and • Add two (2) inches of clean pea gravel to protect the bottom from scouring.

Presoaking the percolation test holes shall be conducted as follows:

• Fill the test hole with a minimum of twelve (12) to fourteen (14) inches of clear water over the gravel or to the ground surface in shallower test holes;

• Refill the test hole as needed or otherwise maintain clear water in the hole for a minimum of four (4) hours. After four (4) hours, allow the water column to drop overnight. Testing must begin twenty-four (24) hours after water was first added to the hole; and

• To prevent sloughing of the sidewall in unstable soils, hardware cloth, perforated pipe or other rigid liner may be used.

Additional tests may be required on a site specific basis for reasons that include the following:

• Unacceptable or failed tests; • Areas of the dispersal field requiring defined limits for exclusion; • The dispersal field is located out of a concentrated area; • Soil conditions are variable or inconsistent; or • To verify suitable soil permeability beneath the chosen leach field depth.

Percolation Rate Determination Depending on the soil type and permeability, and the results of the presoak, variations in the procedures used for determining percolation rates can be allowed. The time interval for readings shall reflect the actual times and shall be maintained as near as possible to the intervals outlined for the test (i.e. ten (10) or thirty (30) minutes). Testing shall proceed based on the conditions outlined in the following cases:1

Case 1. Water remains overnight in the test hole following initiation of the twenty-four (24) hour presoak.

• Adjust the depth of water over the gravel to six (6) inches. • Measure the drop in the water level over a single thirty (30) minute period and

calculate the percolation rate.

Case 2. No water remains twenty-four (24) hours after the presoak period was initiated.

1 In all three of these cases, readings shall be taken from a fixed reference point and shall be accurate to one-sixteenth (1/16) of an inch.

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• Begin the test twenty-four (24) hours after presoak was initiated. • Fill the hole with six (6) inches of water over the gravel. If, after the first two fillings,

the water column seeps away in less than thirty (30) minutes go to Case 3. • If water remains after thirty (30) minutes complete the test by adjusting the water

depth to six (6) inches over the gravel and record the drop at the end of every thirty (30) minute period.

• Including the first two (2) readings above, continue the readings and refilling every thirty (30) minute interval for four (4) hours.

• The last water level drop is used to calculate the percolation rate.

Case 3. No water remains in the hole after the first two (2) thirty (30) minute periods. • Refill the test hole to six (6) inches above the gravel. • Record the water level drop at ten (10) minute intervals for a period of one (1) hour,

refilling to the six (6) inch depth after each reading. • The last water level drop is used to calculate the percolation rate.

Measurements to the nearest one-sixteenth (1/16) inch should be adjusted to the slowest rate. For example, a reading observed between three-eighth (3/8) inch and five-sixteenth (5/16) inch which yields a range of 80 minutes per inch (MPI) to 96 MPI would be reported 96 MPI.

Percolation Rates - Calculation Examples:

For a thirty (30) minute time interval with 0.75 inch drop:

30 𝑚𝑚𝑚/0.75 𝑚𝑚𝑖ℎ = 40 𝑚𝑚𝑚/𝑚𝑚𝑖ℎ(𝑀𝑀𝑀)

For a ten (10) minute interval with a two (2) inch drop:

10 𝑚𝑚𝑚/2 𝑚𝑚𝑖ℎ = 5 𝑚𝑚𝑚/𝑚𝑚𝑖ℎ(𝑀𝑀𝑀)

Special Considerations for Percolation Rates: • Percometer devices are encouraged and are required when conducting tests greater

than sixty (60) inches below the ground surface. • Reports shall be signed with an original signature from the Qualified Professional

who either performed or supervised the testing. • Qualified Professionals who employ technicians are responsible for the work

performed by the technician. It is incumbent upon the Qualified Professional to properly train, equip, and supervise anyone performing work under his or her direction and license.

• The percolation test is only one of several critical factors in siting an OWTS. Site considerations may require special evaluation by a Qualified Professional to technically address issues such as high Groundwater, steep Slope, nitrate impacts, and cumulative impacts such as mounding and loading.

Groundwater Monitoring – Determination Required The end result of Soil Observation Pit(s) or soil borings is to have knowledge of the useable soil depth and depth to Groundwater at the site. However, it is not always possible to determine the depth to seasonal Groundwater by observing soil pits or borings alone. When the highest anticipated depth to Groundwater cannot be determined with the use of Soil Observation Pit(s) or soil borings, CDAEMD may require Groundwater monitoring wells to

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be installed to determine the highest anticipated depth to Groundwater. Groundwater monitoring wells may be indicated if the following conditions exist:

• Vegetation tolerant of, or indicative of, a high Water Table present or in the vicinity of the parcel;

• High Groundwater has previously been found in the vicinity; • Other conditions or historical data preclude accurate determination of the

Groundwater levels; • The Soil Observation Pit indicates less than five (5) feet of the dispersal material over

an impervious stratum, or eight (8) feet for lots less than one acre or for community leach fields; or

• Free water from seepage is observed in the Soil Observation Pit. The height of the seasonal high Groundwater shall be determined by actual measurements of observation wells during periods of maximum soil moisture content, after sufficient precipitation has occurred to meet or exceed field capacity of the soil, and produce a response in observation wells acceptable to CDAEMD.

Groundwater Monitoring - Direct Observation:2

• All of the testing shall be done by, or under the supervision of, a Qualified Professional.

• Standard OWTS are not permitted where Groundwater levels are less than five (5) feet below ground surface.

• The Groundwater measurements shall be taken at the time and intervals specified by the CDAEMD in response to local conditions.

• Except as otherwise directed, measurements shall be taken at monthly intervals from January 1 to April 30.

• At least one (1) observation well shall be included within each proposed dispersal area suspected of having Groundwater less than five (5) feet below the ground surface, except where a nearby monitoring well shows Groundwater contours representative of the proposed dispersal area. Observation well construction guidance is provided in next section.

• If Groundwater levels are less than five (5) feet during any observation, weekly observations shall be recorded throughout the remainder of the wet weather season to ensure that the standards are not exceeded for longer than any two-week period.

• The depth to Groundwater shall never be less than two (2) feet on any observation. • If seasonal rainfall up to the April 30 cutoff date has not exceeded 80% of the normal

rainfall, as determined by the nearest rainfall reporting station approved by the CDAEMD, during the period from December 1 to April 30, testing shall be continued the next year. However, CDAEMD may accept monitoring in years with less than the required amount of rainfall as long as the results appear to represent the highest Groundwater depth for the site.

• Results of all percolation tests and Groundwater monitoring shall be reported and the logs of all excavations shall be submitted to CDAEMD. They shall be accompanied by a plot plan to scale showing the test, well, and pit locations. The map shall include five (5) foot contour intervals. Logs or tests that do not appear to represent soil condition at the parcel may be rejected by CDAEMD.

2 Lots less than one (1) acre in size or community dispersal fields shall be evaluated using either direct observation or using Soil Analysis.

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Observation Well Construction Guidelines Observation wells, for OWTS purposes, are typically completed as follows:

• Soil Observation Pit(s) are converted to observation wells by placing a perforated pipe into the pit prior to backfilling with native soil; or

• A hole is drilled or bored to a desired depth, a perforated pipe is placed into the hole, clean pea gravel is placed around the perforated pipe, and a surface concrete seal is placed.

Observation well construction materials specifications:

• Pipe perforations will be engineered slots, rather than drilled holes; • Filter fabric will be used to cover the perforations in Soil Observation Pit(s); • Use of solid pipe for the upper two (2) feet of the well is required; • A minimum of twelve (12) inches of concrete will be placed on the upper annular

space of drilled/bored wells; • A minimum two (2) mil plastic sheet may be draped over entire excavated area of a

soil pit used as a monitoring well to exclude direct access of surface water into the backfilled pit; and

• At no time is a pit or bored/drilled hole to extend through a restrictive layer. Soil Analysis Alternative to Direct Observation As an alternative to direct observation, an application may be submitted to CDAEMD for individual evaluations utilizing conditions associated with saturation. Conditions associated with saturation include:

• Reddish brown or brown soil horizons with gray (chromas of three or less) and/or red or yellowish red mottles;

• Gray soil horizons, or gray soil horizons with red, yellowish red, or brown mottles; • Dark-colored highly organic soil horizons; or • Soil profiles with concentrations of soluble salts at or near the ground surface.

If conditions associated with saturation do not occur in soil with rapid or very rapid permeability, saprolite, or fractured Bedrock, prediction of the highest level of the Water Table shall be based on direct observations.

• Soil with rapid or very rapid permeability is defined as follows: o Soil which contains 35% or more of course fragments two (2) millimeters in

diameter or larger by volume with interstitial soil of sandy loam texture or coarser;

o Coarse textured soil (loamy sand or sand as classified in a Soil Textural Classification Chart); or

o Stone, cobbles, gravel, and rock fragments with too little soil material to fill interstices larger than one (1) millimeter in diameter.

• Saprolite means weathered material underlying the soil that grades from soft thoroughly decomposed rock to rock that has been weathered sufficiently so that it can be broken in the hands or cut with a knife. It does not include hard Bedrock or hard fractured rock. It has rock structure instead of soil structure.

SECTION 1B. OWTS SITE EVALUATION REPORT AND SITE PLANS The OWTS Site Evaluation Report shall include a site plan, percolation report, design calculations, and four (4) legible copies of the OWTS design. A copy of grading plan shall also be included when required by CDAEMD. The design shall be on a scale not exceeding one (1) inch to fifty (50) feet and shall be not smaller than standard letter sized paper (8 ½

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inches by 11 inches). (NOTE: Design will not be accepted drawn on the grading plan or topographic contour map). A Site Evaluation Report that details test procedures and results shall include the following:

• Current Assessor’s parcel number of property; • The Person who performed the test, his/her address, zip code, phone number, title,

registration number, and signature; • Weather conditions, time, and temperature at time of test; • Water source; • The number of Bedrooms in the existing or proposed structure(s), or number of

fixture units if other than Single Family Dwelling; • The location of test holes on a plot map. Include the contours or direction of Slope of

the land; location of lakes or streams, outcrops, existing or proposed structures, or wells; location and approximate height of road Cuts, if any, and location and type of surface vegetation;

• Depth and soil profiles of each hole; • All percolation rate measurements taken and stabilized percolation rate. Report the

percolation measurements and rates as minutes per inch (the minutes required for the water to drop one (1) inch in a six (6) inch hole);

• Description of soil profile in the leach field area, including roots, clay lenses, rock type and amount, texture, moisture, depth to Groundwater, and other unusual aspects;

• Soil description as per the USDA soil survey of El Dorado County; • Site plan; and • Any special considerations required in the installation of the proposed OWTS.

The site plan shall have following information: • The outline and dimensions of the parcel; • A north arrow and scale; • Proposed project details including exact length, width, and depth of leach lines

(include cross section of trench). (NOTE: designs cannot be deeper than 6 inches of the deepest percolation test hole, but can be shallower);

• Location of 100% / 300% Replacement Area; • Percent of Slope of the ground in the OWTS Disposal Area and the 100% / 300%

Replacement Area. (All development of a parcel shall reserve areas that are less than 30% Slope for Wastewater disposal, unless a Slope stability report is provided by a Qualified Professional);

• Location of land features that may affect the proposed OWTS Dispersal Area(s) (i.e. drainage courses, wet areas, Cut banks, waterways, water bodies, seasonal or dry creek beds, and Slopes greater than 30%);

• Local geology including significant rock outcrops, cuts, and fills; • All roads and driveways shown and labeled, including length, width, turn radius, and

estimated grade; • Frontage road and all easements pertaining to the property, which may affect the

siting of OWTS; • Dimensions, square footage, footprint, and use of all structures, including mobile

homes or houses, attached garage(s) or any other structures on the parcel including proposed structures, retaining walls, and pools;

• All OWTS and well locations, both existing and proposed. Also show the distance to all neighboring OWTS and well(s); and

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• Locations of all percolation tests, soil profile pits, borings, and Groundwater monitoring well, if applicable.

Additional information may be requested for a proposed OWTS based on specific site features or conditions.

The Site Evaluation Report is transferable and runs with the land. The report is based upon property conditions at the time of the site evaluation. Changes made to the property after the site evaluation may render the proposed designated OWTS area unacceptable. Examples of types of changes include: grading, cuts and fills, new buildings, wells, ponds, etc. The property Owner must take care not to encumber or alter the designated area in a manner that affects the future OWTS. Changes in statutes governing OWTS may also necessitate modifications to the site evaluation reporting requirements.

SECTION 1C. PARCEL CREATION For new parcel creation a Site Evaluation Report for each proposed parcel shall be completed for submittal to CDAEMD. Site evaluations shall be scheduled to include CDAEMD in the process. Suitable OWTS Disposal Areas shall be shown on a tentative parcel or subdivision map. Suitable OWTS Disposal Areas shall meet all the requirements for a Standard OWTS or Special Design OWTS, with or without Supplemental Treatment, and shall be located such that there is no conflict with any other applicable County requirements, including those contained in the El Dorado County General Plan. The size of available OWTS Disposal Area shown on each proposed parcel shall correspond to Table 1:

Each parcel shall contain one (1) or more Disposal Areas, each consisting of minimum area as shown in Table 1 with useable soil in locations which could reasonably be utilized by a structure built at a desirable location and feasible site. OWTS receiving a projected flow over 10,000 gallons per day must be referred to California Regional Water Quality Control Board, Central Valley Region (RWQCB) for waste discharge requirements.

Table 1. Minimum Disposal Area Based on Percolation Rate PERCOLATION RATE

(minutes/inch) MINIMUM DISPOSAL AREA

(square feet) Less than 10 6,000 11-20 8,000 21-40 10,000 41-60 12,000 61-80 14,000 81-100 16,000 101-120 18,000 Over 120 Not suitable for development

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SECTION 1D. MINIMUM PARCEL SIZE The average density for any subdivision of property, made by approval of a tentative map pursuant to the Subdivision Map Act, and occurring after the effective date of this OWTS Manual, shall not exceed the allowable density values in Table 2 for a single family Dwelling unit, or its equivalent, for those units that rely on OWTS.

Table 2: Allowable Average Densities per Subdivision AVERAGE ANNUAL

RAINFALL (i / )

ALLOWABLE DENSITY (acres/Single Family Dwelling unit)

0 - 15 2.5 >15 - 20 2 >20 - 25 1.5 >25 - 35 1 >35 - 40 0.75

>40 0.5 SECTION 1E. REVISIONS The Qualified Professional shall approve all revisions to approved site plans. Major revisions require a new site plan reviewed and approved by CDAEMD. Some of the major revisions include: relocating the Disposal Area a significant distance from the approved OWTS area; changes in trench depth and width or type of OWTS; and changes in media used in the trenches.

Minor Revisions that do not require a new site plan include change in tank or distribution box locations or adjustments to the leach lines for contour or obstructions when those changes are within the approved OWTS area. Any changes must meet all other requirements, including setbacks.

SECTION 1F. APPLICATION PROCESS After the site evaluation has been conducted and the Site Evaluation Report has been reviewed by CDAEMD, an application for an OWTS construction Permit must be submitted to CDAEMD for approval. All OWTS construction Permit applications for new installation, repair, replacement, addition, or expansion of OWTS within El Dorado County will be submitted to CDAEMD with the appropriate fees. The application form shall identify the location of the property, Owner, Owner’s authorized representative, Contractor, proposed use, parcel size, specific assessor parcel number, and proposed water supply for the proposed project. The application shall identify any previous land use projects that may have required that soil testing be conducted. The application shall also identify the OWTS project as a new installation, repair, replacement, addition, or expansion. A complete OWTS Permit

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application shall include the Site Evaluation Report. A Permit will only be issued to an Owner or the Owner's authorized representative. SECTION 1G. INSPECTIONS

Installation Inspections Inspections for the installation, replacement, repair, or expansion of OWTS shall only be performed under a valid Permit. The Permit number shall be provided when an inspection is requested. The OWTS shall be accessible and ready for the type of inspection requested. If extra inspections are needed, additional inspection fees may be charged. Open Trench Inspections After obtaining an approved OWTS construction Permit to install, repair, replace or expand an OWTS, an open trench inspection shall be performed by the Qualified Professional on all OWTS. The Qualified Professional shall sign the CDAEMD stamp on the site plan indicating that he/she has conducted the open trench inspection and that it complies with his/her design specifications. (NOTE: this does not preclude the Qualified Professional from performing additional inspections, as he/she deems necessary). At the time of the open trench inspection, all the following shall be completed:

All excavations necessary for the OWTS at designed depth, width, and length; • All smeared or compacted surfaces shall be scarified; • Bottom of the trenches shall be level; and • Minimum setbacks shall be in accordance with the approved site plan. •

Final Inspections Final inspections shall be performed by CDAEMD on all OWTS within two (2) weeks of the open trench inspection. The as-built design site plan and necessary paperwork shall be available on site at the time of the scheduled inspection. A final inspection will only be conducted after the Qualified Professional and the Contractor have signed the approved site plan. The site plan shall show all revisions. At the time of final inspection, all the following shall be completed:

Trenches filled with rock or Medium specified in the design to the specified level •with the filter material in place or gravel-less chambers shall be installed;

Approved distribution boxes, with covers, installed level on undisturbed soil and at •the proper elevation. Sealing around pipe is also to be completed;

All pipe, other than in leach lines, installed on undisturbed soil (1/8 in/ft. minimum •drop), and grouted at tank and distribution boxes;

The Septic Tank set level in place on undisturbed soil. A layer of approved bedding •material may be used;

All trenches shall be left uncovered to the filter material and visible for inspection - •do not backfill unless the filter material cannot be installed in multiple trench designs. When necessary, portions of the trenches may be backfilled with the soil cover to access other trenches. A minimum of ten (10) feet at the ends of the trenches must be left uncovered. The Contractor may have to uncover portions of the trench at the direction of the CDAEMD; and

Observation risers shall be installed in every leach line. •

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SECTION 1H. PROHIBITIONS Pursuant to the State OWTS Policy, the following will not be authorized:

• Cesspools of any kind or size; • Wooden Septic Tanks; • OWTS receiving a projected flow over 10,000 gallons per day; • OWTS that utilize any form of Effluent dispersal that discharges on or above the post

installation ground surface such as sprinklers, exposed drip lines, a free-surface wetlands, a pond, or any other similar surface discharge;

• Slopes greater than 30% without a Slope stability report approved by a Qualified Professional;

• Decreased leaching area for International Association of Plumbing and Mechanical Officials (IAPMO) certified Dispersal System using a multiplier less than 0.70;

• OWTS utilizing Supplemental Treatment without an Operating Permit specifying requirements for periodic monitoring or inspections;

• OWTS dedicated to receiving significant amounts of wastes dumped from recreational vehicle holding tanks; and

• Separation of the bottom of Dispersal System to Groundwater less than two (2) feet, except for seepage pits, which shall not be less than ten (10) feet.

Installation of new or replacement OWTS where public sewer is available will not be permitted in El Dorado County; however, the public sewer may be considered unavailable when such public sewer or any building or exterior drainage facility is located more than two hundred (200) feet from any proposed building or exterior drainage facility on any lot or premises that abuts and is served by such public sewer. In addition, this provision will not apply to replacement OWTS where the connection fees and construction costs are greater than two (2) times the total cost of the replacement OWTS and the CDAEMD determines that the discharge from the OWTS will not affect Groundwater or surface water to a degree that makes it unfit for drinking or other uses. SECTION 1I. ENFORCEMENT Enforcement Actions: As provided for in Ordinance Chapter 110.32, when a violation occurs, CDAEMD may exercise enforcement action in any or all of the following manner(s):

1. Issue a written notice of inspection, correction notice, stop work order, or permit suspension; decline to renew a permit; revoke a permit; deny a permit; and/or record a notice of non-compliance with the County of El Dorado Recorder Clerk’s Office.

2. Impose administrative citations and fines or seek summary abatement pursuant to Chapter 9.02. The Director may serve as the “Enforcement Officer” for purposes of administrative enforcement under Chapter 9.02.

3. Seek reimbursement for the necessary and actual costs incurred to mitigate the threat of contamination and to protect the health and safety of the public pursuant to California Health and Safety Code section 5412.5.

4. Refer the violation to the office of the district attorney for enforcement of any criminal penalty or penalties in accordance with Chapter 1.24.

Enforcement Action Procedures:

• Notice of Inspection: CDAEMD may direct the cessation or correction of a violation or a public health hazard. The notice will direct immediate measures required to eliminate a potential or actual public health hazard or a public nuisance. Failure to

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comply with the requirements of a Notice of Inspection is a violation of the terms of the OWTS Manual, and is subject to any or all of the enforcement actions prescribed in County Ordinance Code.

• Correction Notice: CDAEMD may issue a Correction Notice upon a Person responsible for working on an OWTS or operating an OWTS where that work or operation is in violation of the terms of the OWTS Manual or County Ordinance Code and/or conditions of a Permit. The Correction Notice will state the violation(s). Failure to correct the stated violation(s) is a violation of the terms of the OWTS Manual and is subject to any or all of the enforcement actions prescribed in County Ordinance Code.

• Stop Work Order: CDAEMD may issue a Stop Work Order for work that is in violation of the terms of the OWTS Manual, County Ordinance Code, an OWTS Permit, or is occurring in an unsafe and dangerous manner. The Stop Work Order will be issued to the Person responsible for the work and will specify the reason for the Stop Work Order. It may also direct corrective measures necessary to abate the violation. Work may only recommence upon written release by CDAEMD. Failure to comply with the requirements of a Stop Work Order is a violation of the terms of the OWTS Manual and is subject to any or all of the enforcement actions prescribed in County Ordinance Code.

• Permit Suspension: o Construction Permit: A construction Permit issued by CDAEMD is valid for a

two (2) year period. CDAEMD may suspend a construction Permit when the construction of an OWTS is in violation of the terms of the OWTS Manual, County Ordinance Code, or conditions of a Permit or where a Person has misrepresented any material fact in the application for a Permit. CDAEMD will provide the Owner a written notice of intent to suspend a Permit. The Owner will be given the opportunity to request a hearing with CDAEMD. Within ten (10) working days of the written notice of suspension, CDAEMD must receive a written request for a hearing. Failure to request the hearing within the ten (10) working days is deemed a waiver of the right to a hearing. CDAEMD will schedule a hearing within ten (10) working days from the receipt of a written request for a hearing. The Director of CDAEMD or designee shall conduct the hearing. The decision resulting from the hearing may be appealed in accordance with El Dorado County Code Chapter 110.12. No work may continue on an OWTS where the Permit has been suspended. Work on an OWTS with a suspended Permit may recommence upon reinstatement of the Permit in writing by CDAEMD. Before the Permit will be reinstated, any hourly fees pending shall be paid in full.

• Operating Permit: o An Operating Permit is valid for one (1) year. Failure to pay the required fee or

submit the specified monitoring and inspection information, or failure to undertake any required corrective work specified by CDAEMD, may be cause for issuance of a citation, penalty fees, non-renewal and/or revocation of the operating permit by CDAEMD and referral to the RWQCB.

o The RWQCB may require the owner of the OWTS to submit a report of waste discharge for evaluation on a case-by-case basis. RWQCB response to such reports of waste discharge may include, but is not limited to, enrollment in general waste discharge requirements, issuance of individual waste discharge requirements, or issuance of waiver of waste discharge requirements.

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SECTION 2 – DESIGN PROCEDURES SECTION 2A. GENERAL REQUIREMENTS The following are general requirements for all OWTS. Additional design requirements for Special Design OWTS are provided in Section 2C and for Supplemental Treatment in Section 2D. Wastewater from bathrooms, kitchens, laundry fixtures, and other household, commercial, or industrial plumbing shall pass through a septic or other approved sedimentation tank prior to its discharge into a disposal field. Location No private OWTS, or part thereof, shall be located on any lot other than the lot which is the site of the building or structure served by such private OWTS; nor shall any private OWTS or part thereof be located at any point having less than the minimum setback distances indicated in the OWTS Manual.

Nothing contained in this Manual shall be construed to prohibit the use of all or part of an abutting lot to provide additional space for a private OWTS or part thereof, when a valid transfer of ownership or change of boundary has been first established to the satisfaction of the Director or under circumstances where a recorded easement may be used. The instrument recording such action shall constitute an agreement with the CDAEMD which shall clearly state and show that the areas so joined or used shall be maintained as a unit during the time they are so used. Such agreement shall be notarized and recorded in the office of the El Dorado County Recorder Clerk as part of the conditions of ownership of said properties. A copy of the recorded document shall be filed with the CDAEMD.

Replacement Area All single family residential OWTS , the OWTS shall be designed such that they include the equivalent replacement area of at least 100 percent (100%) of the required original system. No division of the lot or erection of structures on the lot shall be made if such division or structure impairs the usefulness of the 100% replacement area.

Commercial, agricultural, industrial, multifamily, recreational, and mobile home park projects shall require a minimum of 300 percent (300%) replacement area. No division of the lot or erection of structures on the lot shall be made if such division or structure impairs the usefulness of the 300% replacement area.

Septic Tank Capacity Septic Tanks shall be sized following the specifications in Table 3 or based on the most recent version of the California Plumbing Code (CPC).

TABLE 3. SEPTIC TANK CAPACITY1

SINGLE FAMILY DWELLING-

NUMBER OF BEDROOMS

MULTIPLE DWELLING UNITS OR APARTMENTS-

ONE BEDROOM EACH2,3

OTHER USES-MAXIMUM FIXTURE

UNITS SERVED4 (PER TABLE 702.1 OF THE

2016 CALIFORNIA

MINIMUM SEPTIC TANK CAPACITY IN

GALLONS

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PLUMBING CODE) 1-2 -- 15 10005 3 -- 20 1000 4 2 units 25 1200

5 or 6 3 33 1500 -- 4 45 2000 -- 5 55 2250 -- 6 60 2500 -- 7 70 2750 -- 8 80 3000 -- 9 90 3250 -- 10 100 3500

1Septic Tank sizes in the table include sludge capacity and the connection of domestic food waste disposal units without further volume increase. 2Extra Bedroom, one hundred-fifty (150) gallons each. 3Extra Dwelling units of greater than ten (10): two hundred-fifty (250) gallons each. 4Extra fixture units over 100: twenty-five (25) gallons each. 5CPC requires a minimum of 750 gallon septic tank; El Dorado County requires a minimum 1,000 gallon septic tank. Septic Tank Design Minimum Requirements

The liquid capacity of all Septic Tanks shall conform to Table 3 or by the number of •plumbing fixture units as determined from the California Plumbing Code, whichever is greater;

Plans for all Septic Tanks shall be submitted to CDAEMD for approval. Such plans •shall show all dimensions, reinforcing structural calculations, and such other pertinent data as may be required;

Septic Tanks shall be designed to produce a clarified Effluent consistent with •accepted standards and shall provide adequate space for sludge and scum accumulations;

Septic Tanks shall be structurally designed to withstand all anticipated earth or other •loads;

Septic Tank covers shall have watertight risers, the tops of which shall be set at a •minimum of six (6) inches below finished grade and capable of supporting a load of not less than three hundred (300) pounds per square foot or access openings at grade or above shall be locked or secured to prevent unauthorized access.

Fiberglass and polyethylene Septic Tanks must be certified by a Qualified •Professional;

Septic Tanks shall be constructed of solid durable materials, not subject to excessive •corrosion or decay and shall be watertight;

Septic Tanks shall have a minimum of two (2) compartments. The inlet compartment •of any Septic Tank shall be not less than two-thirds (2/3) of the total capacity of the tank and shall be at least three (3) feet in width and five (5) feet in length. Liquid depth shall not be less than two (2) feet, six (6) inches, or more than six (6) feet. The secondary compartment of any Septic Tank shall have a maximum capacity of one-third (1/3) of the total capacity of such tank. In Septic Tanks having over fifteen hundred (1,500) gallons capacity, the secondary compartment may be not less than (5) feet in length;

Access to each Septic Tank shall be provided by at least two (2) manholes twenty •(20) inches in minimum dimension or by an equivalent removable slab cover. One

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access manhole shall be located over the inlet and one access manhole shall be located over the outlet. Wherever a first compartment exceeds twelve (12) feet in length, an additional manhole shall be provided over the baffle wall;

The sidewalls shall extend at least nine (9) inches above the liquid depth. The cover •of the Septic Tank shall be at least two (2) inches above the back vent openings;

Partitions or baffles between compartments shall be of solid durable material and •shall extend at least four (4) inches above the liquid level. An inverted fitting equivalent in size to the tank inlet, but in no case less than four (4) inches in size, shall be installed in the inlet compartment side of the baffle with the bottom of the fitting placed midway in the depth of the liquid. Wooden baffles are prohibited; and

Alternate construction materials shall be approved by the CDAEMD. •

Disposal Field Area Pursuant to the State OWTS Policy, the minimum depth to the anticipated highest level of Groundwater below the bottom of the leaching trench, and the native soil depth immediately below the leaching trench, shall not be less than the following:

Table 4. Minimum Soil Depth Based on Percolation Rate

PERCOLATION RATE MINIMUM DEPTH Percolation Rate 1 to 5 MPI Twenty (20) feet

Percolation Rate >5 to 30 MPI Eight (8) feet Percolation Rate>30 to 120 MPI Five (5) feet

• Effective Soil Depth shall be five (5) feet below the bottom of the design depth; and • Depth to Groundwater shall be a minimum of five (5) feet below the bottom of the

design depth.

Commercial Facilities: • Projected daily flows for Commercial Facilities shall be estimated using the CPC.

CDAEMD may approve, on a case-by-case basis, metered water use data or other reliable supporting data in lieu of the estimated Wastewater flows in the CPC;

• Commercial facilities that prepare foods, (e.g., kitchens, restaurants) shall install a grease trap or interceptor pursuant to the most recent County adopted edition of the CPC and amendments thereto unless an acceptable alternative is recommended by a Qualified Professional and approved by CDAEMD;

• OWTS with Wastewater flows exceeding 10,000 gallons per day will be referred to the RWQCB for approval; and

• Other reliable projected daily flows may be approved by the CDAEMD upon submission of supporting data and calculations.

Disposal Field - Design Requirements A standard disposal field is considered to be three (3) feet wide and three (3) feet deep with a length as required. A non-standard leach line is wider, narrower, and/or deeper than three (3) feet with a length as required. Disposal Field Sizing

• Standard and deep trench systems shall be sized using the following: Table 5. Allowable rate of sewage application to a soil absorption system

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PERCOLATION RATE (time in minutes for water to drop one-inch)

MAXIMUM RATE OF SEWAGE APPLICATION (gallons per square foot per day)1 for adsorption trenches,2 seepage beds,

and seepage pits3 1 or less 5.0

2 3.5 3 2.9 4 2.5 5 2.2 10 1.6 15 1.3 30 0.9 45 0.8 604 0.6

1Not including Effluent from Septic Tanks that receive wastes from garbage grinders. 2Absorption Area is figured as trench bottom area and includes a statistical allowance from vertical sidewall area. 3Absorption Area for seepage pits is effective sidewall area. 4Percolation rates other than those listed up to 120 MPI use: 5 divided by the square root of the percolation rate. Example 1 – Absorption trenches:

Amount of Wastewater for disposal = 2,000 gallons per day; Percolation rate is 1-inch in five (5) minutes; and From Table 5 the maximum rate of sewage application is 2.2 gallons per square foot per day.

2,000 𝑔𝑔𝑔/𝑑𝑔𝑑 ÷ 2.2 𝑔𝑔𝑔/𝑓𝑓2 = 𝟗𝟗𝟗𝒇𝒇𝟐 of Absorption Area required

Example 2 – Seepage Pits – using 2,000 gallons per day of Wastewater flow: 𝜋𝜋(𝑑) = 909 𝑓𝑓2

Where the diameter of the pit (D) is 10 feet and (d) is the effective depth in feet. Solving for d:

𝑑 = 909𝑓𝑓2/(3.14)(10𝑓𝑓) 𝒅 = 𝟐𝟗 𝒇𝒇

Therefore more than one (1) pit will be needed. To design for two (2) pits, 10 feet in diameter:

𝑑 = 29 𝑓𝑓/2 = 𝟏𝟏.𝟓 𝒇𝒇 depth for each pit • Disposal Field Design based on Soil Data (reference 2016 California Plumbing Code,

Table H201.1(3)):

Table 6. Design Criteria Using Soil Data SOIL TYPE REQUIRED SQUARE FEET

OF LEACHING AREA PER 100 GALLONS OF WASTEWATER

MAXIMUM ABSORPTION CAPACITY IN GALLONS PER SQUARE FEET OF

LEACHING AREA FOR A 24 HOUR PERIOD

Coarse sand or gravel 20 5.0

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Fine sand 25 4.0 Sandy loam or sandy clay 40 2.5 Clay with considerable sand or gravel 90 1.1 Clay with small amount of sand or gravel 120 0.5

• For gravel-less OWTS: Size the disposal field according to the manufacture’s specifications. High capacity gravel-less chambers equal five (5) square feet per lineal foot and in accordance with CDAEMD for the Medium to be used in the OWTS.

EZ Flow or equivalent designs are calculated the same as a graveled trench side wall plus the bottom area of the trench.

SECTION 2B. SETBACKS 1. General setback requirements are provided in Table 7.

Table 7. General Setback Requirements

FEATURE REQUIRING SETBACK DISPOSAL FIELD AND REPLACEMENT AREA (ft)

SEPTIC TANK (ft)

Domestic well or spring 100 100

Seasonal wet area 50 50

Ephemeral stream or drainage course1 50 25

Lake or pond used for drinking water2 200 100

Flowing stream, lake, pond, marsh or wetland2 100 50 Domestic water service lines, lot lines, road

easements, driveways, buildings3 5 5

Cuts or fills (down gradient)

Four (4) times maximum depth below grade, 25 feet

maximum 10

Swimming pools 10 5

1 As measured from the edge 2 As measured from the ten (10) year high water mark 3 Buildings include porches and steps, whether covered or uncovered, breezeways, roofed porte-cocheres, roofed patios, carports, walks, covered driveways, and similar structures or appurtenances

In addition to those setbacks cited on Table 7, Dispersal Areas shall not be permitted in the following areas:

• Land subject to flooding. In case of disputes concerning flooding potential, the flooded area shall be determined by calculating the expected ten-year frequency flood;

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• Land closer than two hundred (200) feet to a lake or reservoir, measured from the high water line or one hundred (100) feet if down Slope from the lake or reservoir;

• Land closer than two hundred (200) feet to any spring, or 100 feet if downhill from the spring;

• Land within one hundred (100) feet of any existing or proposed private well site for the parcel or any adjoining parcel;

• Land one hundred-fifty (150) feet from a public water well where the depth of the Effluent Dispersal System does not exceed 10 feet in depth;

• Land two hundred (200) feet from a public water well where the depth of the Effluent Dispersal System exceeds ten (10) feet in depth. Land within and two hundred (200) feet from public wells;

• Where the Effluent dispersal system is within six hundred (600) feet of a public water well and exceeds twenty (20) feet in depth and the separation from the bottom of the OWTS and Groundwater is less than five (5) feet the horizontal setback required to achieve a two-year travel time for microbiological contaminants shall be evaluated. A Qualified Professional shall conduct this evaluation. However in no case shall the setback be less than two hundred (200) feet;

• Land closer than one hundred (100) feet to an intermittent, seasonal, or Perennial Waterway measured from the top of the bank or other physically evident high water line. An intermittent stream is one which may continue to flow for five days or more after the passage of a storm;

• Land closer than fifty (50) feet to an Ephemeral Stream, measured from the edge of a channel;

• Land closer than fifty (50) downhill from an irrigation ditch or canal; • Land closer than fifty (50) uphill from an existing or proposed Cut; • Land with a grade steeper than 30 percent (30%) unless there is a Slope stability

report completed by a Qualified Professional; • Filled land, unless the fill is engineered for sewage dispersal and approved by

CDAEMD; • Gravel bars of very porous materials adjoining a stream or body of water; • Land used for utility or road easements. Overhead utility easements may be included

if the utility, entity, or agency holding the easement gives a permanent and irrevocable release, easement, or license for sewage dispersal within the easement;

• Where the Effluent Dispersal System is within twelve hundred (1,200) feet from a public water system surface water intake point, and within the catchment of the drainage, and located such that it may impact water quality at the intake point such as upstream of the intake point for flowing water bodies, the Dispersal System shall be no less than four hundred (400) feet from the high water mark of the reservoir, lake, or flowing water body; and

• Where the Effluent Dispersal System is located more than twelve hundred (1,200) feet but less than twenty five hundred (2,500) feet from a public water system surface water intake point and within the catchment area of the drainage, and located such that it may impact water quality at the intake point such as upstream of the intake point for flowing water bodies, the Dispersal System shall be no less than two hundred (200) feet from the high water mark of the reservoir, lake, or flowing water body.

For replacement OWTS that do not meet the above horizontal separation requirements, the replacement OWTS shall meet the horizontal separation to the greatest extent practicable. In such cases, the replacement OWTS shall utilize Supplemental Treatment and other mitigation

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measures, unless the CDAEMD finds that there is no indication that the existing OWTS is adversely affecting a public water source and there is limited potential that the replacement OWTS could impact a water source based on topography, soil depth, soil texture, and Groundwater separation.

New OWTS installed on parcels of record existing at the time of the effective date of this OWTS Manual that cannot meet the above horizontal separation requirements, shall meet the horizontal separation to the greatest extent practicable and shall utilize Supplemental Treatment for pathogens.

Supplemental Treatment components designed to perform disinfection shall provide sufficient pretreatment of the Wastewater so that Effluent from the Supplemental Treatment components does not exceed a thirty (30) day average Total Suspended Solids (TSS) of thirty (30) mg/L and shall further achieve an Effluent fecal coliform bacteria concentration less than or equal to two hundred (200) Most Probable Number (MPN) per 100 milliliters. SECTION 2C. SPECIAL DESIGN OWTS A Special Design OWTS is any CDAEMD approved OWTS that is not a Standard OWTS.

All Special Design OWTS shall require written certification by the Qualified Professional that the Special Design OWTS has been installed and completed under his or her supervision and according to the approved site plan. The written certification shall be a wet signature on the CDAEMD stamp located on the site plan. (Example below)

The following are Special Design OWTS requiring CDAEMD approval:

• OWTS infill • Capping fill OWTS • Pressurized distribution OWTS* • Pump systems • Steep slopes greater than 30% • Mound OWTS* • Large OWTS* • Supplemental Treatment OWTS* (see Section 2D)

SPECIAL DESIGN ONSITE WASTEWATER TREATMENT SYSTEM I hereby certify that this Special Design OWTS has been installed and completed under my supervision according to the approved site plan, construction permit, and according to the El Dorado County OWTS Manual and Ordinance Chapter 110.32. Date: _____________ Signature: __________________________ Registration Number: ___________________________________ Contractor: _________________________________________

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*Shall require annual Operating Permits specifying monitoring and reporting requirements. Unless otherwise indicated in Special Design OWTS sections or by CDAEMD, site evaluation criteria, design (including sizing), installation, and construction shall be in accordance with this OWTS Manual. All Special Design OWTS shall be installed by a Contractor. OWTS Infill An OWTS infill is a Special Design OWTS where the disposal trench is in compacted fill.

Compaction shall be completed in six (6) inch lifts and supervised by a Professional •Civil Engineer or Professional Geologist.

Compaction test data shall be provided to ensure proper compaction to nearly the •same degree as native soil.

Area to receive fill shall have the vegetation removed and shall be plowed, ripped, •scarified, or disked on contour.

The imported material shall have consistent characteristics as the native soil with a •percolation rate equal to or slower than the percolation rate of the native soil, but not greater than one hundred twenty (120) MPI.

Area to receive fill shall be less than 20% Slope unless the Qualified Professional •makes a site specific justification and approval by CDAEMD.

Capping Fill OWTS A capping fill OWTS is a Special Design OWTS where the disposal trench effective sidewall is installed a minimum of twelve (12) inches into native soil below a soil cap of specified depth and texture (Diagram 1). The shallow construction of the capping fill OWTS allows for installation where depth to a limiting layer or Groundwater is closer to ground surface. This section describes the requirements for gravity-fed capping fill OWTS. Pressure-dosed capping fill OWTS shall meet the requirements of this section as well as the next section: Pressurized Distribution OWTS.

In order to be approved for a capping fill OWTS, each site must meet all of the following conditions:

• The Slope shall not exceed 20% in the Disposal Area and Replacement Area; and • Unless otherwise approved by CDAEMD, the Effective Soil Depth shall be a

minimum of five (5) feet below the bottom of the disposal trench and depth to Groundwater shall be five (5) feet minimum.

Unless otherwise specified, the capping fill OWTS shall conform to the provisions of this OWTS Manual and the following:

• Disposal trench depth of twelve (12) inches minimum; • Disposal trench width of eighteen (18) inches minimum / Thirty-six (36) inches

maximum; • Cap depth of twelve (12) inches minimum (after settling); • The cap soil texture shall be of the same textural class as the native topsoil or one

textural class finer; • The Disposal Area shall have the vegetation removed and shall be scarified, parallel

to contours, and no deeper than six (6) inches; • Soil cap shall extend a minimum of five (5) feet beyond the exterior trench sidewall

and have a three (3) foot horizontal to one (1) foot vertical ratio;

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• The site shall be protected from erosion in accordance with County and Resource Conservation District erosion control requirements; and

• Capping fill finish grade elevation shall be determined using an established benchmark to ascertain there is twelve (12) inches minimum fill.

Required inspections by the Qualified Professional: • The Disposal Area and fill material shall be inspected for scarification, soil texture,

and moisture content prior to backfill of the installed disposal field; and • The final placement of the soil cap.

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Diagram 1 - Capping Fill System

Pressurized Distribution OWTS Pressurized Distribution OWTS is a Special Design OWTS where the Effluent is evenly distributed over the entire soil Absorption Area through a network of small diameter pipes under low pressure. Pressurized Distribution OWTS will require an annual Operating Permit. Design, materials, and construction requirements:

• The proposed Disposal Area and Replacement Area shall demonstrate a minimum of five (5) feet of Effective Soil Depth beneath the disposal trench bottom;

• All materials used in pressurized systems shall be structurally sound, durable, and capable of withstanding normal stresses incidental to installation and operation;

• Nothing in these rules shall be construed to set aside applicable building, electrical, or other codes. An electrical permit and inspection from the Community Development Agency, Development Services Division (CDADSD) shall be obtained if required for pump wiring installation;

• For Pressurized Distribution OWTS where trench depth is less than twenty-four (24) inches, percolation tests shall be performed in the layer of most restrictive permeability that occurs within five (5) feet of the trench bottom. The deeper percolation test data shall be considered in the site evaluation design of the OWTS; and

• Piping, valves, and fittings for pressurized systems shall meet the following minimum requirements:

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o All pressure transport, manifold, distribution lateral piping, and fittings shall meet or exceed the requirements for Schedule 40 PVC pressure pipe as identified in ASTM Specification D1785 or other material approved by the CDAEMD;

o All pressure distribution laterals and fittings shall be adequately sized for the design flow; a minimum of two (2) feet per second velocity at the end of the OWTS and a minimum three (3) feet residual head;

o All pressure transport and manifold piping shall be adequately sized for the design flow and minimum two (2) feet per second velocity;

o Pressure transport piping shall be uniformly supported along the trench bottom, and at the discretion of CDAEMD, it shall be bedded in sand or other material approved by CDAEMD;

o The ends of lateral piping shall have blow-off risers that accommodate threaded plugs or caps (Diagram 2);

o All joints in the pressure distribution manifold, lateral piping, and fittings shall be solvent welded, using the appropriate solvent for the pipe material. Pressure transport piping may be solvent welded, threaded, or rubber ring jointed;

o A ball valve shall be placed on the pressure transport pipe, near the dosing tank, when required; and

o A check valve shall be placed between the pump and the ball valve, when required. A check valve is not required if the pump has an internal check valve. All check valves and ball valves must be in an accessible and protected location for maintenance and repair.

Diagram 2 - Disposal Trench Risers

• The pump shall meet the minimum design, materials, and construction standards for

use in Wastewater applications. • Dosing tank design, materials, and construction requirements:

o Materials and construction for dosing tanks shall have a minimum capacity of five hundred (500) gallons;

o The float level elevations shall be clearly identified on the plan; o A minimum 1,500-gallon Septic Tank must be used; o In no event shall the liquid portion be drawn down to within twelve (12) inches

of the tee fitting or baffle slot in the common compartment wall; and o The pump must be located within a screened vault.

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• The dose volume shall be calculated using the following minimum and maximum dosing range formulas:

𝑉𝑚𝑚𝑚 = 𝑉𝑠 + 5𝑉1

𝑉𝑚𝑚𝑚 = 𝑉𝑠 + 10𝑉1

Where: Vmin is the minimum volume of dose Vmax is the maximum volume of dose Vs is the volume of supply line V1 is the total volume of lateral lines

Disposal trench design, materials, and construction requirements:

• Disposal trenches shall be constructed using the specifications for the standard disposal trench, except for the following: o Pressure lateral piping shall have a minimum six (6) inches of filter material

below and not less than one (1) inch of filter material above the piping; o Depth shall be a minimum of one (1) foot; o Bottom width shall be a maximum of three (3) feet; and o Length of lateral shall be limited to that length which will result in no more than

a 10% head loss over the length of the lateral. • The top of the filter material shall be covered with filter fabric or other material

approved by the CDAEMD; • A minimum of twelve (12) inches of backfill is required over the soil barrier material

within the disposal trench; • Inspection and blow-off risers constructed in accordance with Diagram 2 shall be

placed at the end of the pressure distribution lateral within the disposal trench; and • All orifices of pressure distribution laterals shall face upward and shall be covered

with orifice shields to prevent soil washout. Hydraulic design criteria:

• There shall be a minimum six (6) feet head (squirt) at the most remote orifice and no more than 10% head variation between the most near and remote orifices within a disposal field;

• Lateral piping shall have discharge orifices drilled upward, a minimum diameter larger than screen filter holes of one-eighth (1/8) inch, and evenly spaced at a distance not greater than two (2) feet in coarse textured soils or greater than six (6) feet in finer textured soils;

• Unless otherwise indicated on the Permit or elsewhere in this section, the installation standards specified in this manual shall apply: o The pressure distribution lateral laid within the center of the trench above the

gravel shall be level to within two (2) inches in one hundred (100) feet; o Each dosing tank shall be installed on a stable level base; o Each dosing tank shall be provided with a watertight riser extending to the

ground surface or above, with a minimum inside horizontal measurement equal to or greater than the tank access manhole. The watertight riser shall meet the materials and construction provisions in the section for Septic Tanks; and

o Dosing tanks located in high Groundwater areas shall be weighted or secured to prevent flotation.

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Sloping site requirements: • Ball valves or flow restrictors shall be installed on each pressure distribution lateral

to facilitate regulation of flow within each lateral; • Where the disposal field is located down Slope from the pump, an anti-siphon device

placed at the highest point on the supply line to the trenches shall be installed in the dosing tank; and

• Additional required inspections include the following: o Inspection of the dosing system components, e.g., the location of the pump,

screen, switches, alarms, and valves; and o Inspection of the pressure distribution system and verification of hydraulic head

over the pressure distribution laterals.

Pump Systems Pump systems are typically utilized to enable the installation of a disposal field up Slope of the structure to be served. Wastewater flows by gravity to a Septic Tank followed by a pump tank, where the Effluent is distributed to the disposal field by pumping to a higher elevation. Pressure-dosed pump OWTS shall meet the requirements of this section as well as the previous section: Pressurized Distribution OWTS.

Criteria for approval:

• Drainage from Septic Tanks located below the level of the disposal field shall discharge into a separate, approved, watertight pump tank. The pump tank shall receive Septic Tank Effluent only;

• All pump systems shall have a surge box or distribution box; • Community Service Districts maintained by a Public Entity shall follow their

approved OWTS design guidelines; • Nothing in these rules shall be construed to set aside applicable building, electrical,

or other codes. An electrical permit and inspection from the CDADSD shall be obtained if required for pump wiring installation; and

• Unless otherwise indicated on the Permit, installation requirements shall conform to the provisions of this OWTS Manual.

Pump tank requirements:

• The pump tank shall be located to receive the Wastewater by gravity drainage; • Pump tanks shall be watertight and constructed of approved materials and in

accordance with specifications for Septic Tanks; • The pump tank shall have capacity sufficient to deliver the design dose and have a

minimum capacity of five hundred (500) gallons; • Each pump tank shall be provided with a riser extending to the ground surface or

above, with a minimum inside horizontal measurement equal to or greater than the tank access manhole. The lids to the tank shall be water tight. Provision shall be made for securely fastening the manhole cover to prevent entrance by unauthorized persons; and

• Pump tanks in high Groundwater areas shall be weighted or secured to prevent flotation.

Piping Requirements:

• The drainage piping connecting the Septic Tank and the pump tank shall be at least three (3) inches in diameter;

• The pump discharge piping shall be sized to adequately handle all expected flows;

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• The discharge piping shall be provided with an accessible check valve and ball valve; • Class 200 PVC water pipe or equivalent shall be used; and • Velocities shall be maintained between two (2) to ten (10) feet per second.

Mechanical Device Requirements:

• Check valves, ball valves, pumps, motors, switches, and other mechanical devices required by this section shall be located where they will be readily and easily accessible for inspection and repair at all times and shall be enclosed in a watertight pit fitted with an adequately sized removable cover, unless continuously exposed;

• Check valves, ball valves, pumps, motors, switches, and other mechanical devices shall be designed and manufactured to operate in Septic Tank Effluent or Wastewater;

• The pumps shall be made specifically for Wastewater; • All devices and equipment associated with pump tanks shall be protected by a

weatherproof structure; and • All pump tanks shall be equipped with a high water level alarm system.

Inspection Requirements:

• Qualified Professionals shall inspect the open trenches and the pump during operation for proper velocities;

• Pump Systems and alarms shall be operational at the time of final inspection; and • Final sign off shall not occur until the electrical OWTS Permit has been approved by

the CDADSD. Steep Slope OWTS Steep Slope OWTS is a Special Design OWTS installed on sites with Slopes greater than 30%. Slopes greater than 30% must have a Slope stability report approved by a Qualified Professional. For proposed developments on Slopes exceeding 30%, the septic Effluent disposal field shall be placed on the portions of the property having the lowest Slope gradient unless physical conditions on the site, as documented by the Qualified Professional, render such placement infeasible or in conflict with other requirements as determined by the CDAEMD. A steep Slope OWTS shall meet the following requirements:

• The Qualified Professional shall address distance from trench sidewall to soil surface (sidewall break out distance) and it shall be a minimum of twenty-four (24) inches to flow line as measured on the downhill side;

• Steep Slope OWTS will not be approved on unstable landforms; and • For steep Slope OWTS the site shall be protected from erosion in accordance with

County and Resource Conservation District erosion control requirements. Mound OWTS A mound OWTS is an aboveground absorption field useful in mitigating some of the limitations associated with inadequate Effective Soil Depth. The mound OWTS consists of a distribution network that, under pressure (see section regarding Pressurized Distribution OWTS), evenly delivers Effluent from a Septic Tank to a “mounded” bed of filter material over sand media or other media approved by CDAEMD. Mound OWTS are Special Design OWTS that require an annual Operating Permit.

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Mound OWTS shall meet the following requirements: • An absorption rate of 1.2 gallons per day per square foot (based on 150 gallons per

Bedroom per day) shall be used for calculating the mound sand bed area; • Sand media as defined in Table 8 shall be used for the sand bed; and • Unless otherwise approved, the mound OWTS shall only be considered for use for a

single-family Dwelling and shall not be installed on Slopes greater than 5%.

Table 8. Sand Specifications for Sand Filter Mounds

SIEVE SIZE PERCENT PASSING THROUGH

3/8 100

4 95-100

8 75-85

16 45-55

30 20-30

50 5-15

100 0-2

200 0

Large OWTS Large OWTS have projected daily Wastewater flows greater than two thousand five-hundred (2,500) gallons, and have waste characteristics other than typical residential, from either a residential or Commercial Facility. Large OWTS are Special Design OWTS and shall require an annual Operating Permit. Projected daily Wastewater flows greater than ten thousand (10,000) gallons must be reviewed and approved by the RWQCB.

The County may allow community OWTS and other alternative solutions as an acceptable option to traditional Wastewater treatment for mobile home parks, commercial and industrial centers, and multifamily residential. The Applicant must prove, and the County must find, that the proposed OWTS will be adequately and safely operated and can accommodate the highest possible demand of the project. Community OWTS in remote areas may be considered where the geology may not be conducive to constructing individual OWTS. Unless otherwise authorized by CDAEMD, designs for large OWTS shall meet, at a minimum, all of the following:

• The Disposal and Replacement Areas shall be divided into a minimum of two (2) disposal fields;

• Effluent distribution shall alternate between the disposal fields; • If the OWTS is pumped, it shall have at least two (2) alternating pumps; and • Unless otherwise specified, Septic Tank design, materials, and construction shall

conform to the provisions of this OWTS Manual. SECTION 2D. SUPPLEMENTAL TREATMENT OWTS

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Supplemental Treatment OWTS are Special Design OWTS that may be used to serve individual single-family residences, multi-family residential structures, commercial establishments, and institutional or industrial facilities. Supplement Treatment OWTS are required for OWTS that cannot meet setbacks and where Groundwater is less than five (5) feet but not more than two (2) feet below the depth of the Disposal Area. Supplemental Treatment OWTS shall require an annual Operating Permit. All Supplemental Treatment OWTS shall be installed by an approved Contractor that is familiar with the Supplemental Treatment OWTS being installed. All Supplemental Treatment OWTS must be American National Standards Institute (ANSI) or National Sanitation Foundation (NSF) approved unless otherwise exempted by CDAEMD. Notwithstanding any other provisions, final approval of Supplemental Treatment OWTS proposals shall be at the discretion of the Director.

Design standards Engineering plans and site data for Supplemental Treatment OWTS shall be submitted in accordance with Standard OWTS application procedures. Site evaluations, including soil profile evaluation and percolation testing, shall be conducted in accordance with standard procedures provided in Section 1A: Site Evaluation of this OWTS Manual. However, soil separation between the bottom of the dispersal field and high seasonal Groundwater, impervious layer of soil or Bedrock, or fractured/weathered Bedrock may be reduced to two (2) feet.

OWTS with Supplemental Treatment components shall be equipped with a visual or audible alarm as well as a telemetric alarm that alerts the Owner and Service Provider in the event of OWTS malfunction. OWTS using Supplemental Treatment shall, at a minimum, provide for twenty-four (24) hour Wastewater storage based on design flow as a means to minimize Pollution from overflow discharge after an OWTS malfunction or power outage.

Inspections Designs for Supplemental Treatment OWTS shall be signed by a Qualified Professional. The Qualified Professional shall also be responsible for inspection of OWTS installation to assure conformance with approved plans and shall provide an as-built drawing of the installation to the CDAEMD and property Owner. The construction inspection by the Qualified Professional shall be in addition to the CDAEMD inspection. The Qualified Professional shall provide a construction inspection schedule which identifies critical inspections to be conducted by the Qualified Professional. Operation, maintenance and monitoring instructions The Qualified Professional shall provide operation, maintenance and monitoring instructions in the design which are brief and simple guidelines regarding the operation of the OWTS, Owner’s responsibilities, and OWTS monitoring requirements.

SECTION 2E. OPERATING PERMITS In addition to a construction Permit, an Operating Permit is required for steep slope, large OWTS, mound OWTS, pressurized distribution OWTS, and Supplemental Treatment OWTS. The provisions outlined in this section may also apply to any Special Design OWTS if determined necessary by the CDAEMD.

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Operating Permits shall be issued at the time of final approval of the OWTS and they are required to be renewed every year. Operating Permits shall also be renewed at the time of sale of the parcel or, in the case of commercial properties, upon change of occupants where the sewage flows increase or change significantly and may affect the OWTS operation.

The Operating Permit shall include a contract with a Service Provider to inspect the OWTS every six months and to file a report with CDAEMD within thirty (30) days after the inspection. Further, if the OWTS has a grease trap or interceptor, it shall be inspected and cleaned every 3 months, or more frequently if needed.

Operating Permits when required are intended to serve as the basis for verifying the adequacy of OWTS performance, maintenance and continued proper operation for the protection of public health and safety and the environment. The property owner must record the Operating Permit for the parcel with the El Dorado County Recorder Clerk’s Office. Operating Permit conditions shall include monitoring and inspection requirements, Permit duration, and other provisions that may be specified by the Qualified Professional. The Owner for the OWTS shall grant access to CDAEMD for periodic inspection of OWTS operation. Renewal of an annual Operating Permit requires payment of applicable fees and the results of required OWTS biannual monitoring and inspection, if not previously provided. Failure to submit a required fee, or specified monitoring and inspection data, or failure to undertake any required corrective work specified by CDAEMD may be cause for non-renewal or revocation of the Operating Permit. The unpaid balance on the Operating Permit shall be sent to El Dorado County Revenue Recovery and further enforcement action may be pursued against the property Owner pursuant to the Enforcement provisions of this OWTS Manual and County Ordinance Code 110.32. At the time a property is transferred or sold, an Operating Permit application, the most recent biannual inspection report, and applicable fees shall be remitted to CDAEMD within thirty (30) days of close of escrow or property sale. Performance Monitoring and Reporting

• Monitoring of OWTS subject to annual Operating Permits shall be conducted by a Service Provider. CDAEMD may conduct spot-check inspections of Supplemental Treatment OWTS and may also be present to observe the performance of monitoring activities conducted by the Service Provider.

• Monitoring requirements will vary depending upon the specific type of OWTS but, in general, they will include the following: o Recording of Wastewater flow based on water meter readings, pump event

counters, elapsed time meters, or other approved methods; o Inspection and recording of water levels in any monitoring points in the disposal

field; o Inspection and observation of pump operation or other mechanical equipment; o General inspection of treatment and Disposal Area for evidence of seepage,

Effluent surfacing, erosion, or other indicators of OWTS malfunction; o The frequency of monitoring shall be in accordance with the manufacturer’s

specification for OWTS performance requirements (where an Operating Permit is required), but monitoring shall be conducted at least twice per year;

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o Monitoring frequency may be increased if OWTS problems are experienced; • A monitoring report shall be submitted to CDAEMD biannually within thirty (30)

days after the inspection. The monitoring report shall be signed by the Service Provider responsible for the monitoring. CDAEMD shall be notified immediately of any OWTS problems observed during routine inspection and monitoring, or at any other time.

SECTION 3 – MATERIALS, CONTRUCTION, AND INSTALLATION3 SECTION 3A. SEPTIC TANK

Installation – General Provisions

• The Septic Tank shall be set level in place on undisturbed soil. A layer of approved bedding material may be used;

• Septic Tanks installed in areas subject to vehicular traffic shall be designed to support an H-20 AASHTO traffic loading;

Septic Tanks shall not be installed in areas of high Water Table unless specifically •designed to account for this situation;

Septic Tanks installed under concrete or black top paving shall have the required •manholes accessible by extending the manhole openings to grade meeting H-20 AASHTO traffic loading;

Effluent filters designed to prevent solids in excess of one-eighth (1/8) inch in •diameter from passing to the disposal field are required in the sanitary tee on the outlet side of the Septic Tank; and

• Fiberglass and Polyethylene Tank Requirements: o Shall be bedded on at least six (6) inches of sand or soil not containing large or

sharp rocks; o Shall be bedded to the horizontal midpoint of a sewer pipe (spring line) with

select material, hand tamped in not over twelve (12) inch lifts, or pond and jetted; and

o Shall be covered from the spring line up with material that will not puncture the tank. Care shall be taken during placement to minimize settling.

Fittings

The inlet and outlet pipe openings and fittings shall not be less in size than the •connecting sewer pipe. A baffle type fitting shall have the equivalent cross-sectional area of the connecting pipe and not less than four (4) inch horizontal dimension when measured at the inlet and outlet pipe inverts;

The inlet and outlet pipe or baffle (sanitary tee) shall extend four (4) inches above •and at least twelve (12) inches below the water surface. The base of the inlet pipe shall be at a level not less than two (2) inches above the base of the outlet pipe; and

Inlet and outlet pipe fittings or baffles, and compartment partitions shall have a free •vent area equal to the required cross-sectional area of the house sewer or private sewer discharging therein to provide free ventilation above the water surface from the

3 All Special Design OWTS shall be installed by a licensed Contractor, holding an A, C12, or C42 license.

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disposal field or seepage pit through the Septic Tank, house sewer, and stack to the outer air.

SECTION 3B. SERIAL DISTRIBUTION MATERIALS AND CONSTRUCTION (See Diagram 3) Serial distribution shall be used for gravity fed OWTS where multiple trenches are utilized unless otherwise approved by CDAEMD.

Diagram 3 - Serial Distribution

Distribution Box Construction At a minimum distribution boxes shall be constructed as follows:

• Distribution boxes shall be constructed of concrete, high density polyethylene, or other materials acceptable to CDAEMD;

• Distribution boxes shall be watertight and designed to accommodate the necessary distribution laterals and expected flows. The top, walls, and bottom of concrete distribution boxes shall be at least one and one-half (1.5) inches thick;

• Distribution boxes, when used, shall be installed level on undisturbed soil or on concrete, with leach field piping to allow serial distribution to multiple leach lines; and

• Distribution boxes shall be installed on native soil with a five (5) foot separation from leach lines by an undisturbed soil platform.

Serial distribution • Serial distribution is to be utilized on sloping ground as determined by the Qualified

Professional; • Each horizontal leaching trench shall be utilized to the maximum capacity before the

Effluent shall pass to the next lower leach line; • The lines between each horizontal leaching section shall be made with watertight

joints;

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• Connections between a Septic Tank and a distribution box, or between a distribution box and a leach line, shall be laid in native ground; and

• Effluent sewer pipe, header pipe, and fittings (all Tight Line). Tight Line shall extend a minimum of five (5) feet out of the distribution box toward Disposal Area.

Pipe Fitting

• Pipe fittings shall meet the minimum standards established in Section 3A; • Pipe fittings shall be located within the disposal trench, firmly bedded in the filter

material; • All joints shall be glued so as to be watertight; and • Diversion valves shall be constructed of durable material and be corrosion-resistant,

watertight, and designed to accommodate the inlet and outlet pipes. CDAEMD shall approve all diversion valves.

SECTION 3C. EFFLUENT PUMP, CONTROL, AND ALARM MATERIALS Unless otherwise specified, Effluent pumps, control boxes, and alarm materials, and their construction, shall be in conformance with this section.

Electrical Components Electrical components used in OWTS shall comply with the California Uniform Electrical Code and the following provisions:

• Pumps shall be automatically controlled by sealed mercury float switches with a minimum mercury tube rating of twelve (12) amps at one hundred fifteen (115) volts AC or by a CDAEMD approved equivalent;

• Pumps shall have automatically resetting audible and visual high water level alarm with manual silence switch that is located in or near the building served by the pump. The audible alarm shall be installed and constructed so that it can only be canceled by the user;

• Wiring must be of proper construction and gauge and permanently fixed to a supporting structure under permit from the CDADSD;

• The pump and alarm must be connected to separate circuits; • Pump control panel shall have a cycle counter and an elapsed time meter; and • There shall be a manual override switch in the electrical box to facilitate dosing

control during inspections.

SECTION 3D. PIPING MATERIALS AND CONTRUCTION

Effluent Sewer Pipe and Pressurized Pipe Unless otherwise specified, piping shall consist of materials and be constructed in conformance with the standards of this section:

All piping shall be free of defects or damage; • All connection of pipes of different diameters shall be glued with the proper fittings; • Effluent sewer, header pipe (Tight-Lines), and fittings shall be a minimum four (4) •

inch diameter, watertight, and shall be one of the following: o Schedule 40 PVC that meets the most current American Society for Testing

Materials (ASTM) D-2672 for minimum four (4) inch pipe;

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o Schedule 40 Acrylonitrile-Butadiene-Styrene (ABS) that meets the most current ASTM Specification D-2468;

o ASTM SDR 35 with solvent-welded or rubber-gasket joints; or o Other material approved by CDAEMD.

• Pressure transport pipe, pressure distribution manifolds, and pressure distribution laterals (piping and fittings) shall meet the most current requirements for schedule 40 PVC pressure pipe as identified in ASTM Specifications D-1785 or other material approved by CDAEMD;

• Pressure transport pipe, pressure distribution manifolds, and pressure distribution laterals shall be adequately sized for the design flow;

• Tight-Line under driveways shall be Schedule 40, SDR 35, or other approved pipe with at least twelve (12) inches of natural soil cover; and

• Suspended tight line crossing streams or drainage courses shall be piped and installed within a protective sleeve of approved material that extends ten (10) feet on each side of the seasonal or high water mark for the seasonal drainage course or twenty five (25) feet for a year-round stream. Crossings above streams or drainage courses shall be designed to support the weight of the sleeve, the tight line flowing full, and other loading conditions as set forth in the Uniform Building Code. Crossings above the stream or drainage course shall be installed a minimum of one (1) foot above the 100 year recurrence interval high water level.

Perforated Pipe

Perforated distribution piping for gravity flow OWTS shall be a minimum of four (4) •inches diameter, constructed of 3000 HDPE (or equivalent) that meets the most current ASTM Specifications F-810 or other material approved by CDAEMD.

Perforated distribution piping for gravity flow OWTS shall have two (2) rows of •holes spaced one hundred-twenty (120) degrees apart and sixty (60) degrees on either side of a centerline facing down.

SECTION 3E. OWTS WITH A CURTAIN DRAIN General Requirements Unless otherwise approved, a curtain drain (Diagram 4) shall meet the minimum requirements as follows:

• All curtain drains shall be designed and inspected by a Qualified Professional; • Curtain drains shall be ten (10) to fifteen (15) feet uphill from the Disposal Area and

the outflow shall be placed so as to not to affect the OWTS; • All other requirements for OWTS approval, except depth to Groundwater, shall be

met at the time of installation. After the drain is installed, the depth to Groundwater shall conform to the requirements for vertical separation to Groundwater for the proposed OWTS; and

• CDAEMD has the discretion of requiring demonstration that a proposed curtain drain is effective prior to issuing a construction Permit.

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Diagram 4 - Curtain Drain

Design, Construction, and Materials

• The trench shall be situated so that captured water drains by gravity flow out of outlet pipes.

• Trench bottoms shall maintain a minimum of 1% Slope throughout the drainage trench. In areas where the outlet pipe will be subject to damage, the pipe shall be adequately protected.

• The trench shall be a minimum of twelve (12) inches wide. It shall extend from ground surface at least six (6) inches into a limiting layer. For a vertical drain, the trench shall penetrate through the limiting layer into a permeable soil.

• The bottom and the downhill side of the trench may be lined with a waterproof barrier. Material shall be equivalent to two (2) layers of six-mil. plastic. The waterproof barrier shall be placed along the downhill side of the trench wall and at the bottom of the trench.

• A four (4) inch minimum diameter perforated pipe approved for use in OWTS shall be laid the entire length of the trench with two (2) inches of gravel underneath the pipe.

• The drain trench shall be filled with Drain Rock. Prior to backfilling the trench, the Drain Rock shall be covered with filter fabric. A minimum of six (6) inches of soil cover shall be placed over the trench.

• In the event that the discharge outflow from a curtain drain will impact a neighboring property, the trench outlet from the drain shall only discharge into a

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drainage channel or other conveyance designed for the transport of water, unless otherwise approved by CDAEMD.

SECTION 3F. DISPOSAL FIELD INSTALLATION AND MONITORING Construction Disposal fields shall be protected from vehicle traffic, and confined animal and livestock areas and shall remain unencumbered by structures, above ground swimming pools, and any other use that may damage or compact the soil above the disposal field. Variances when proposed by a Qualified Professional will be reviewed and approved on a case by case basis. Disposal fields shall be constructed as follows:

Depth of natural earth over the entire disposal field as measured from the lowest •point of natural grade is twelve (12) inches;

Maximum "drop" in leach line drain pipe and/or the bottom of trench is three (3) •inches maximum in a one hundred (100) feet line;

Minimum spacing of leach lines is ten (10) feet center-to-center; • Minimum trench width is eighteen (18) inches; • Tight Line shall have minimum Slope of one-eighth (1/8) inch per foot; • Drain line pipe ends must be capped; • Observation risers shall be installed in every leach line; • Chambers or other media OWTS shall be installed in accordance to manufacturer’s •

specifications and approval by CDAEMD; All smeared sidewall surfaces shall be scarified; • Drain Rock shall be clean, sound, gravel or crushed rock ranging in size from 3/4 to 1 •

½-inch diameter, with less than 5% outside this range. Rock and gravel shall contain no more than 1% fines, dust, sand, or clay by weight (less than 1% by weight passing the #200 sieve);

The drain lines shall be covered with a minimum two (2) inch of Drain Rock, and •then covered with an approved soil barrier cover of filter fabric, untreated paper, or straw to prevent closure of voids with earth backfill;

No earth backfill shall be placed over the soil barrier cover until after inspection and •approval by CDAEMD;

Multiple disposal field laterals, wherever practical, shall be of uniform length; and • Where two (2) or more drain lines are installed, distribution boxes or pipe fitting •

Distribution shall be provided in accordance with Diagram 5.

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Diagram 5 - Pre Cast Distribution Box

SECTION 3G. COMMERCIAL OR INDUSTRIAL SPECIAL LIQUID WASTE DISPOSAL

Effluent containing commercial or industrial waste which could affect the satisfactory functioning of an OWTS shall have pretreatment devices such as an interceptor tank. Food facilities that generate grease connected to an OWTS shall be required to install a grease interceptor that is at least five hundred (500) gallons unless an acceptable alternative is recommended by a Qualified Professional and approved by CDAEMD. All interceptors shall be sized, installed, and operated based on the manufacturer’s instructions and shall meet the most recently adopted CPC requirements.

Liquid waste containing hazardous substances may not be discharged into an OWTS. SECTION 3H. CESSPOOLS AND HOLDING TANKS The installation of Cesspools and similar excavations are prohibited in the County. Any existing cesspool discovered by CDAEMD through the repair or complaint process, or through an application to increase the capacity of any existing OWTS, shall be properly

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destroyed and replaced with an OWTS acceptable under the LAMP and OWTS Manual and approved under the same process noted in Section 4, Repair or Additions to OWTS. Permits will not be issued for the construction of any cesspool. The installation of Holding Tanks is not an approved method of sewage disposal in the County. Exemption to this prohibition may be granted by CDAEMD if it is necessary to use a Holding Tank to abate a nuisance or health hazard caused by an OWTS failure while that OWTS is properly repaired. Such exemption shall only be granted for a limited time as determined by CDAEMD. This prohibition does not apply to pre-existing, approved holding tanks whose continued use may be allowed unless the Director determines that the holding tank poses a threat of pollution or risk to public safety. Any change to that approval shall be at the discretion of the Director.

SECTION 3I. PORTABLE AND VAULT TOILETS Portable Toilets are intended to serve non-residential, limited use activities, such as field labor operations, special events, and temporary construction sites where connection to a sanitary sewer system or installation of an OWTS is not practicable. Portable Toilets must be removed within seven (7) days of conclusion of operations, events, or construction. Any other use of Portable Toilet(s) will require approval by the Director.

The use of vault toilets or semi-permanent Portable Toilets at a publicly owned, non-residential facility (i.e., seasonal cabins on federal land or state, county or city parks) may be allowed by CDAEMD where the vault toilet or semi-permanent Portable Toilet is necessary for the public health, safety, or welfare, and where installation of an OWTS is not feasible, and a vault toilet or semi-permanent Portable Toilet is determined by CDAEMD to provide the safest and most acceptable method of sewage disposal.

Vault toilets may be allowed by CDAEMD when an individual OWTS cannot be constructed. Vault toilets shall meet the following requirements:

Vaults shall be watertight; • Vaults shall be maintained to prevent health hazards and Pollution; • Vaults shall be pumped by a licensed Septic Tank pumper at the end of each season, •

at a minimum, and pumper’s receipt shall be submitted to CDAEMD within thirty (30) days of pumping;

Plans and specifications for composting or other alternative toilets shall be submitted •along with certification from NSF or other organization for review by CDAEMD; and

Gray water shall be disposed of in a watertight holding tank which shall be pumped •out by a licensed Septic Tank pumper or other sub-surface method approved by CDAEMD. Gray water shall not be directly discharged onto the ground surface.

SECTION 4 - REPAIR OR ADDITIONS TO EXISTING OWTS SECTION 4A. COMPLAINT INVESTIGATION PROCEDURES – NOTIFICATION OF FAILURE

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Upon receipt of a complaint report from a member of the public or a notification by a property Owner, Qualified Professional, or Service Provider, a violation file will be generated with an assigned tracking number. Upon investigation and confirmation of a Failing OWTS, CDAEMD will issue a Notice of Violation directing the property Owner to eliminate the immediate health hazard through pumping of the septic tank by a licensed septic tank pumper or by the elimination of Wastewater flows from the structure. These actions shall continue until the OWTS has been repaired/replaced and final approval granted by CDAEMD. If known, the Notice of Violation shall note why the OWTS is failing and with the specific corrective actions needed. CDAEMD will also require proper destruction of any cesspool found in use by issuing a Notice of Violation directing abatement. A new OWTS will be required for use. The Notice of Violation shall require repairs to the OWTS, as needed, within a reasonable time frame. An Inspection Report or Warning Notice may also be issued to the property Owner at the time of the site inspection. Subsequently, a Notice of Violation detailing required corrective actions and time frames may be issued if the identified failure cannot be corrected immediately. The proposed repair/replacement by a property Owner and/or Contractor in an OWTS Permit application shall be evaluated by CDAEMD to ensure it meets the minimum design requirements of the OWTS Manual or that the proposed repair is otherwise in substantial conformance to the greatest extent practicable. Any OWTS component failure such as a broken distribution box or broken piping connection (a minor failure), shall have that specific component repaired in a timely manner, and inspection from CDAEMD, so as to return the OWTS to proper functioning condition without the requirement to bring the entire OWTS into compliance with the OWTS Manual.

In the event of failure of a Septic Tank (a major failure), such as a baffle, "tee," or loss of structural integrity, Groundwater intrusion, or sewage/Effluent discharge, CDAEMD will require that the Septic Tank be repaired or replaced to bring the tank into compliance with the Septic Tank specifications in the OWTS Manual within a timely manner. An OWTS Permit application will be required and a Permit must be issued by CDAEMD noting the corrections required. The OWTS may not be backfilled or placed into use without an inspection and final approval from CDAEMD. In the event of the failure of a Supplemental Treatment OWTS or a Dispersal System (a major failure), the Failing OWTS and/or components shall be brought into compliance with the OWTS Manual within a timely manner. Replacement of the Failing OWTS with a Standard OWTS, Special Design OWTS, or OWTS with Supplemental Treatment will be specified in an OWTS Permit issued by CDAEMD. The OWTS may not be backfilled or placed into use without an inspection and final approval from CDAEMD. Supplemental Treatment may be required in situations where ground or surface waters have been impacted by the Failing OWTS.

Soil tests by a Qualified Professional may be required at the discretion of CDAEMD to properly characterize the site with a Failing OWTS. Groundwater separation requirements from the bottom of the Dispersal System and the highest anticipated Groundwater level for repairs are the same as those for newly constructed systems: minimum of five (5) feet (based

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on soil percolation rates) for standard systems and no less than two (2) feet for systems with Supplemental Treatment and/or an alternate Dispersal System. Required correction(s) shall be completed under Permit and inspection from CDAEMD within specified time frames. No component of an OWTS shall be backfilled and placed into use until authorized in writing by CDAEMD staff after an inspection confirms substantial compliance with valid CDAEMD Permit conditions and the standards in this OWTS Manual.

SECTION 4B. REPAIR CRITERIA A repair of an existing septic OWTS occurs when an OWTS is failing and can include either the Septic Tank or the leach field, or both. A repair Permit is required in order for any Person to install, replace, abandon, or change an OWTS. A separate construction Permit shall be required for expansion purposes or relocation of an OWTS to enable construction of additional structures. A repair does not increase the size capacity of the original OWTS. SECTION 4C. DESIGN FOR SINGLE FAMILY DWELLINGS The Qualified Professional can use any existing records for the parcel that are maintained at CDAEMD (percolation rate, design calculations, and/or original design) to calculate the size and design of the repair. If data are not available a site evaluation and percolation tests will be required. SECTION 4D. SMALL PARCELS AND LIMITED AREA FOR REPAIR Owners of existing developed parcels that do not have adequate area available for a complete OWTS repair may be required to remove minor structures (sheds or other out-buildings) along with trees and other landscaping in order to provide an adequate area for a complete repair. Owners may be advised to consider obtaining an easement from an adjacent property in order to provide adequate area for a complete repair.

If all possibilities for a complete disposal field replacement have been exhausted, an OWTS repair can be approved with the expansion of the disposal field as long as the expansion conforms with this OWTS Manual and the LAMP to greatest extent practicable.

When possible, a diversion valve shall be installed to allow for future use of the existing failing leach line after a drying out period.

Deep trenches shall only be considered after a site inspection by Qualified Professional is performed and it is verified that there is not adequate area available for a typical leach field.

SECTION 4E. REPAIRS FOR COMMERCIAL PROPERTIES Repairs for commercial properties shall require a site evaluation by a Qualified Professional that is knowledgeable and experienced in the field of OWTS design and installation.

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SECTION 4F. REPAIRS USING PUMP SYSTEMS The repaired pump system operation shall be inspected during the final inspection of the OWTS. If the pump system is not operational at the time of the final inspection, an additional inspection and fee shall be required. The pump system inspection is a joint inspection conducted by CDAEMD and the Qualified Professional or the Contractor.

Electrical components and connections of a repair shall be permitted and inspected by the CDADSD. Repair Permit will not receive final approval by CDAEMD until final approval of the electrical permit by the CDADSD.

SECTION 4G. ABANDONED SEWERS AND WASTEWATER DISPOSAL FACILITIES

Every cesspool, Septic Tank, or seepage pit which has been abandoned shall have the lids removed and contents pumped out by a licensed Septic Tank pumper. The empty Septic Tank shall be completely filled with earth, sand, gravel, concrete, or other approved material. The top cover or arch over the cesspool, Septic Tank, or seepage pit shall be removed before filling for inspection by CDAEMD. After the inspection has been completed by CDAEMD, the cesspool, Septic Tank, or seepage pit shall be filled to the level of the top of the ground. Where OWTS are abandoned consequent to connecting any premises with the public sewer, the OWTS shall be properly abandoned as required by CDAEMD within thirty days (30) from the time of connecting to the public sewer.

SECTION 4H. REPORTING TO OWNERS OF PUBLIC WATER SYSTEMS AND DIVISION OF DRINKING WATER AT THE SWRCB CDAEMD shall notify the Owner of a public well or water intake and the Division of Drinking Water at the SWRCB as soon as is practicable, but not later than seventy-two (72) hours, upon verification of a major failure of an OWTS component within:

• 150 feet of a public water well; and • Within 2,500 feet from a public water system surface water intake.

Additionally, CDAEMD will notify the public water system prior to the issuance of a new installation or repair Permit for an OWTS if a surface water intake is within twelve hundred (1,200) feet of a proposed OWTS, is within the drainage catchment of the intake point, and is located such that it may impact water quality at the intake point or if the proposed OWTS is within the horizontal sanitary setback from a public well. Notification is to be made by CDAEMD upon receipt of an application for a new or repair Permit and prior to issuance of the Permit. Notifications will be made via email or United States mail, or other means that may be available in the future. For OWTS Permit applications for Dispersal Areas within the horizontal sanitary setback of a public well or a surface water intake point, CDAEMD shall first work with the Owner of the proposed OWTS to see if relocation of the Dispersal Area is possible. Per the State OWTS Policy, an OWTS with Supplemental Treatment for nitrogen reduction and Supplemental

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Treatment for pathogen reduction may be required if the Dispersal System cannot be relocated to meet the required setback.

SECTION 5 – DEFINITIONS

In addition to the definitions provided in the LAMP, the following definitions apply for purposes of this Manual:

American Society for Testing Materials (ASTM): A technical organization which publishes national standards for the testing and quality assurance of construction materials.

Absorption Area: The sidewall area of a trench below the distribution pipe, except for gravel-less chambers which include both the sidewall area and the trench bottom.

Applicant: An Owner or Owner's authorized representative.

Bedrock: The rock, usually solid, that underlies soil or other unconsolidated surface material.

Bedroom: Any room designated as such by the CDADSD.

Commercial Facility: Any structure or building, (excluding single-family and multi-family residential Dwellings), or any portion thereof, intended for commercial or industrial use.

Contractor: A Person who possesses an active Class A, B-1 or C-42 contractor's license in accordance with the provisions of the California Business and Professions Code.

County: County of El Dorado

Cut: Any altered area of land surface having a distinctly greater slope than the adjacent ground surface, over 24 inches in vertical height or the OWTS Dispersal System backfill cover depth, whichever is greater, and any part of which is lower in elevation than the ground surface at the nearest point of the OWTS. Cuts supplied by retaining walls or other similar structures shall be included in this definition, as shall be steep natural ground surfaces where a sharp break in the ground slope is discernable.

Director: The Director of the El Dorado County, Community Development Agency, Environmental Management Division, or designee.

Dispersal System: A leachfield, seepage pit, mound, at-grade, subsurface drip field, evapotranspiration and infiltration bed, or other type of system for final wastewater treatment and subsurface discharge.

Disposal Area: The entire area used for underground dispersion of the liquid portion of Wastewater.

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Drain Rock: Clean, sound gravel or crushed rock ranging in size from 3/4 to 1-1/2inch diameter with <5% outside this range. Rock and gravel shall contain no more than 1% fines, dust, sand, or clay by weight (less than 1% by weight passing the #200 sieve).

Dwelling: Any structure or building or any portion thereof, which is used, intended, or designed to be occupied for human living purposes including, but not limited to, houses, manufactured homes, houseboats, boathouses, mobile homes, travel trailers, hotels, motels, and apartments.

Effective Soil Depth: The depth of soil material from ground surface that effectively provides filtration of effluent. Effective soil excludes soil layers that meet the criteria for soil with rapid permeability (<5 MPI.), Groundwater conditions associated with saturation and limiting layers" (<15% porosity).

Effluent: The partially treated, liquid portion of Wastewater.

Ephemeral Stream: A stream, or other drainage such as a roadside ditch, that flows for less than five (5) days after the passage of a storm. An ephemeral stream only carries water in direct response to a precipitation event and it contains no water from a spring, snow, or other long-continuing surface source and does not discharge to a perennial aquifer.

Failing OWTS: The ineffective dispersal of waste resulting in the surfacing of sewage or inadequately treated sewage Effluent and/or the degradation of surface or groundwater quality.

Gray Water: Untreated Wastewater that has not come into contact with toilet wastes. It includes used water from bathtubs, showers, bathroom washbasins, and from clothes washing machines and laundry tubs. It does not include Wastewater from kitchen sinks, dishwashers or laundry water from soiled diapers.

Groundwater: A layer or lens of soil or fractured Bedrock in which all open spaces are filled with water. The thickness and extent of Groundwater may vary seasonally or periodically in response to changes in the rate or amount of Groundwater recharge or discharge.

Medium: Drain Rock, chambers, EZflow or other approved material used to fill the void of a dispersal trench.

Owner: Any Person who alone, or jointly, or severally with others:

a. Has legal title to any single lot, Dwelling, Dwelling unit, or Commercial Facility. b. Has care, charge, or control of any real property as agent, executor, executive

administrator, administrative trustee, commercial lessee, or guardian of the estate of the holder of legal title; or the Owner's authorized representative.

Perennial Waterway: A stream or other drainage which has continuous flow in all or parts of its stream bed all year during normal rainfall years but may flow only intermittently in drought years.

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Permit: A written document issued by CDAEMD that allows the construction, installation, use, repair, expansion, replacement, or destruction of an existing OWTS or any part thereof.

Person: Includes individuals, corporations, associations, firms, partnerships, joint stock companies, public and municipal corporations, political subdivisions, cities, counties, the State and any agencies thereof, and the Federal government and any agencies thereof.

Pipe Fitting Distribution (Crossover Unit): A series of pipefittings connected to the distribution pipe providing serial distribution of Effluent in the disposal field.

Pollution: The undesirable change in the physical, chemical, or biological characteristics of air, land, and water that may or will harmfully affect human life or that of other desirable species, industrial processes, living conditions, and cultural assets; or that may or will waste or deteriorate raw material resources.

Public Entity: A local agency that is empowered to plan, design, finance, construct, operate, maintain, and to abandon, if necessary, any OWTS or the expansion of any Wastewater treatment facilities serving a land development as defined in the State of California Government Code Section 53090.

Qualified Professional: An individual licensed or certified by a State of California agency to design OWTS and practice as a professional for other associated reports, as allowed under his/her license or registration. Depending on the work to be performed and various licensing and registration requirements, this may include an individual who possesses a Registered Environmental Health Specialist certificate or is currently licensed as a professional engineer or professional geologist. For the purposes of performing site evaluations, soil scientists certified by the Soil Science Society of America are considered Qualified Professionals. Qualified Professionals would be expected to conduct onsite surveys for OWTS suitability, evaluate potential pathways of Wastewater-sourced phosphate and other nutrients toward potentially threatened nearby wells or surface bodies of water, consider hydraulic mounding and linear loading at the site, complete all necessary soils tests, prepare system designs and drawings, meet with Owners and Contractors, and conduct necessary inspections. No other Person, license, or registration/certification will be approved as a Qualified Professional.

Replacement Area: An area that is one hundred (100) percent in size of the area approved for the initial sewage system disposal field for a residence and three hundred (300) percent in size of the area approved for the initial sewage system disposal field for others.

Septic Tank: A water tight, covered receptacle designed for primary treatment of wastewater and constructed to:

1. Receive wastewater discharged from a building or other use; 2. Separate settleable and floating solids from the liquid; 3. Digest organic matter by anaerobic bacterial action; 4. Store undigested solids; and 5. Clarify wastewater for further treatment/subsurface discharge.

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Service Provider: A Person approved by CDAEMD who is capable of operating, monitoring, inspecting and maintaining an OWTS in accordance with this OWTS Manual.

Single Family Dwelling: A Dwelling designed for and commonly occupied exclusively by one family and served by one OWTS.

Slope: The rise or fall of vertical elevation in feet, per one hundred (100) feet of horizontal distance. Slope is expressed as a percent of grade. For example, a rise of 30 feet in a 100 foot run is a 30 percent slope. A rise of 40 feet in a 100 foot run is a slope of 40 percent.

Soil: The naturally occurring body of porous mineral and organic materials on the land surface, which is composed of unconsolidated materials, including sand-sized, silt-sized, and clay-sized particles mixed with varying amounts of larger fragments and organic material. The various combinations of particles differentiate specific soil textures identified in the soil textural triangle developed by the United States Department of Agriculture (USDA) as found in Soil Survey Staff, USDA; Soil Survey Manual, Handbook 18, U.S. Government Printing Office, Washington, DC, 1993, p. 138. For the purposes of this OWTS Manual, soil shall contain earthen material of particles smaller than 0.08 inches (2 mm) in size.

Soil Observation Pit: An excavation of sufficient size and depth to allow thorough examination of the soil to evaluate its suitability for Wastewater disposal.

Special Design OWTS: OWTS that does not meet the criteria for a State OWTS Policy Tier 1 Standard OWTS.

Standard OWTS: An OWTS constructed in soil meeting State OWTS Policy Tier 1 specifications. A Standard OWTS consists of a Septic Tank and a series of subsurface dispersal trenches for subsurface dispersal of Effluent into the soil. A Standard OWTS may utilize gravity flow or a pump OWTS to convey Effluent from the Septic Tank to the drain field.

Supplemental Treatment: Any OWTS or component of an OWTS, except for a septic tank or dosing tank, that performs additional Wastewater treatment using intermittent and recirculating sand filters, proprietary treatment units, and other alternative treatment systems approved by the Director, so that the Effluent meets a predetermined performance requirement prior to discharge of the Effluent into the dispersal field. Some Supplemental Treatment units are passive and can be placed directly onto a leach bed for direct dispersal into the soil.

Tight Line: The solid distribution pipe that conveys the Effluent from the Septic Tank to the disposal field including the distribution laterals.

Wastewater: Blackwater, Gray Water, and/or any liquid contaminated with materials thereof.

Water Table: That level of Groundwater where the hydraulic pressure is zero.

Documents

EL DORADO COUNTY · which in El Dorado County is the Community Development Agency, Environmental Management Division (CDAEMD). The SWRCB adopted the State OWTS Policy on June 19,