PROJECT BRIEFING Benedict Central Sewer System

PROJECT BRIEFING

Benedict Central Sewer System

September 11, 2012

BENEDICT CENTRAL SEWER SYSTEM PROJECT OVERVIEW

• Project Purpose: To design and construct a centralized

wastewater collection, treatment, and disposal system to

replace all individual on-site septic systems with a public

sewer system.

• There are 209 developable lots, of which, 123 or 58.8% are

developed.

• In the mid-80’s a public water system was installed due to the

contamination of wells by nitrates from septic systems.

(Source: Charles County Health Dept.).

• Feasibility Study completed in 2004 by Wallace Montgomery

& Associates (WMA) to identify and evaluate alternatives for

sanitary sewerage collection, treatment, and disposal.

• Project Design began in February of 2009.

2

2 mi.

BENEDICT CENTRAL SEWER SYSTEM CONCEPTUAL LAYOUT

3

4

BENEDICT CENTRAL SEWER SYSTEM CONCEPTUAL LAYOUT

• DISPOSAL SITE AREA

BENEDICT CENTRAL SEWER SYSTEM DISCHARGE OPTIONS

1. Surface Water Discharge

(Denied by MDE - Shellfish Harvesting Designation for the

Patuxent River).

2. Effluent re-use by Chalk Point Power Plant (Insufficient

Flow to meet needs).

3. Land Application (further investigation):

• Rapid Infiltration

• Large On-Site Disposal System

• Slow Rate Infiltration (Spray/Drip Irrigation)

5

Criteria:

• Land Area:

• 0.29 ac. to 5.84 ac.

• Soils:

• 10 feet of separation from groundwater

• Well to excessively drained soils; sandy loam to

sand (2 to 20 inches/hour permeability)

Based on a Web Soil Survey Analysis it was determined that

finding a site with favorable conditions would be very difficult in

Charles County within 6 miles.


LAND APPLICATION – RAPID INFILTRATION

6


LAND APPLICATION – LARGE ON-SITE DISPOSAL

Criteria:

• Land Area:

• 25 to 37 acres (based on the highest permitted

loading rate of 1.2 gallons/square foot

• Soils


• Well Drained Soils

• Uniform Soil Material is ideal

MDE suggested that locating 25 to 35 acres that will allow a

uniform loading rate 1.2 gals/sq. ft. will likely be very difficult.

Therefore, this option was excluded from further consideration.

7


LAND APPLICATION – SLOW RATE INFILTRATION

Criteria:

• Land Area:

• Spray: 17 – 294 ac.

• Drip: 24 – 468 ac.

• Soils:


• Moderately well to excessively well drained soils

(0.2 to 6 inches/hour permeability)

This option was used as the basis for site selection.

8

BENEDICT CENTRAL SEWER SYSTEM DISCHARGE SITE SELECTION

Query Results (40+ acres within 3 miles of Benedict)

9


Query Results/Usable Acreage Analysis

• Most Favorable

• Favorable

• Least Favorable

• Sites Eliminated from Search

• 1, 2, & 4 – Steep Slopes

• 6 – Under Development

• 7 – Marsh Land

• 9, 12, & 13 – DNR Property

• 14 – Small Usable Area

• 15 – Ag. Preservation

10

• Preliminary site testing performed on Amberleigh Farms.

• As a backup plan, expand search to include sites of 10 - 40 acres

(multiple disposal sites).

• 15 additional sites were selected.

• Letters of Interest mailed to 19 property owners.

• Received 10 responses; (9) positive, (1) negative, and (1) returned

undeliverable.

• Of 9 properties that provided positive responses, 4 properties

were selected for preliminary soils testing by Health Dept. (all

found favorable). Backup plan in place.


11

• Hydrogeological Study initiated for Amberleigh Farms property in

April 2010.

• Study completed October 2010.

• Study Results:

• Site is most sufficient for spray irrigation

• Site insufficient for drip irrigation, trench, sand mound, and

rapid infiltration systems

• Minimum required area = 21.2 acres

• Site Disposal capacity = 62,160 gpd (design flow is 58,863 gpd)


12

BENEDICT CENTRAL SEWER SYSTEM DISCHARGE PERMIT APPLICATION

• Groundwater Discharge Permit Application submitted to MDE

in June 2011.

• Public Notice of permit advertised by MDE on March 7th and

again on March 14th of 2012.

• Public Hearing requested.

• Public Hearing held on May 23, 2012.

• 2nd Public Hearing held on June 26, 2012.

• Permit issuance pending environmental site assessment.

13

• Collection System (Gravity): $2,283,722

• Treatment System: $3,393,605

• Disposal System & Force Main: $3,265,544

TOTAL = $8,942,871

Cost/Developed Property (123) = $72,706

Cost/Property (209) = $42,788

Original Cost Estimate : $3,243,412

Cost/Existing Resident (123) = $26,369

Cost/Property (233) = $13,920

BENEDICT CENTRAL SEWER SYSTEM CONSTRUCTION COST ANALYSIS

14

BENEDICT CENTRAL SEWER SYSTEM FISCAL NOTE

• Current Construction Budget = $3,234,000

• Future Funding:

• FY14: $1,210,000

• FY15: $2,956,000

• Total Construction Funding: $7,400,000

• Additional funding needed = $1.5M

• Est. property acquisition costs = $430,000

• Current ROW Budget: $100,635

• Additional ROW funding needed = $330,000

• Total additional project funding needed = $1.83M

15

16

Presented by:

Charles County Government

Planning & Growth Management Peter Aluotto, Director

200 Baltimore Street, La Plata, MD 20646

301-645-0641

E-mail: [email protected]

www.CharlesCountyMD.gov

Mission Statement

The mission of Charles County Government is to

provide our citizens the highest quality service

possible in a timely, efficient, and courteous

manner. To achieve this goal, our government must

be operated in an open and accessible atmosphere,

be based on comprehensive long- and short-term

planning, and have an appropriate managerial

organization tempered by fiscal responsibility.

We support and encourage efforts to grow a

diverse workplace.

Vision Statement

Charles County is a place where all people thrive

and businesses grow and prosper; where the

preservation of our heritage and environment is

paramount, where government services to its

citizens are provided at the highest level of

excellence; and where the quality of life is

the best in the nation.

Documents

PROJECT BRIEFING Benedict Central Sewer System