Lansing Wet Weather Control Plan

7/30/2019 Lansing Wet Weather Control Plan

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The City of Lansing

2012 Wet Weather Control

FINAL DRAFT

June 2011


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THE CITY OF LANSINGWET WEATHER CONTROL PLAN

JUNE 2011PROJECT NO. G080700XI

FINALDRAFT


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TABLE OF CONTENTS

1.0 EXECUTIVE SUMMARY .........................................................................................2.0 INTRODUCTION .....................................................................................................3.0 CURRENT WET WEATHER CONTROL PROGRAM AND FACILITIES ..................

3.1 Combined Sewer Overflow (CSO) Control Program .......................................3.1.1 1991 Project Plan ........................................................................................3.1.2 Project Plan Amendment No. 3 ...................................................................3.1.4 National Pollutant Discharge Elimination System (NPDES) Permit ...........

3.2 Sanitary Sewer Overflow Control Program......................................................3.2.1 2003 Sanitary Sewer System Master Plan ................................................3.2.2 Administrative Consent Order (ACO) .........................................................3.2.3 2008 CSO Program Evaluation Report ......................................................

3.3 SSO and Emergency Bypasses .......................................................................3.4 Basement Backup Protection ..........................................................................3.5 Storm Water Program ......................................................................................

3.5.1 Municipal Separate Storm Sewer Systems (MS4s) - General Permit .......3.6 WWTP .............................................................................................................

3.6.2 Permit Requirements ..................................................................................3.6.3 Historical Wet Weather Flows .....................................................................

4.0 TRIPLE BOTTOM LINE...........................................................................................5.0 WET WEATHER MANAGEMENT - CAPACITY NEEDS ASSESSMENT ..............

5.1 Hydraulic Model Development .........................................................................5.1.1 Conveyance System Capacity ....................................................................

6.0 WET WEATHER CONTROL ALTERNATIVES - ANALYSIS ..................................6.1 Balanced System Approach ............................................................................6.2

Wet Weather Control Measures ......................................................................6.2.1 Combined Sewer Areas ..............................................................................6.2.1.1 Preliminary Analysis of Combined Sewer Areas ..............................6.2.1.2 Combined Sewer Separation ............................................................6.2.1.3 RTBs ..................................................................................................6.2.1.4 CSO Control Cost Estimates ............................................................

6.2.2 SSO Control ...............................................................................................6.2.2.1 Balanced System Approach .............................................................6.2.2.2 Peak Flow Equalization .....................................................................6.2.2.3 Source Removal - Footing Drain Disconnection (FDD) ...................

6.2.3 Emergency Bypasses .................................................................................6.2.4 Basement Backup Prevention .....................................................................6.2.5 WWTP .........................................................................................................6.2.6 Storm Water Management .........................................................................

7.0 RECOMMENDED WET WEATHER CONTROL PLAN ............................................7 1 Priority Projects


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TABLE OF CONTENTS

7.3.2 Financing Options ......................................................................................7.3.2.1 Project Plan Amendment ...................................................................

8.0 REGULATORY COMPLIANCE ...............................................................................8.1 Integrated Regulatory Compliance Strategy ...................................................

9.0 IMPLEMENTATION .................................................................................................9.1 Prioritization ......................................................................................................9.2 Schedule ...........................................................................................................9.3 WWCP Updates and Administration ................................................................

LIST OF FIGURES

Figure 1.0 Recommended Wet Weather Control PlanFigure 3.1 Remaining CSO RegulatorsFigure 3.3.1 Historical Bypass PumpingFigure 3.4.1 Sewer Complaints 2007 - 2009 ReportFigure 3.5.1 City of Lansing Storm Water OutfallsFigure 3.6.3.1 WWTP Peak Hourly Flows and Average Daily FlowFigure 3.6.3.2 Peak Hourly Flows and Effluent NH3-N

Figure 5.1.1 System SurchargeFigure 6.1 Collection System CapacityFigure 6.2.1 Remaining Combined Sewershed LocationsFigure 6.2.2.1 Hybrid AlternativeFigure 6.2.2.2 Regional Equalization AlternativeFigure 6.2.2.3(a) Building Construction EraFigure 6.2.2.3(b) FDD Target AreasFigure 6.2.3 Emergency Bypass LocationsFigure 6.2.5.1 WWTP Hydrograph

Figure 6.2.5.2 Process DiagramFigure 6.2.5.3 Process Diagram with HRTFigure 6.2.5.4 Process Diagram with 23 MG Equalization BasinFigure 6.2.5.5 WWTP Sewers and BasinFigure 9.1 Project Prioritization Flow Chart

LIST OF TABLES

Table 1.0 WWCP Project CostsTable 3.1.1 Lansing Combined Sewer Separation CompletedTable 3.6 Lansing WWTP Summary of Unit ProcessesTable 3.6.3.2 Lansing WWTP Treated Effluent Characteristics for the Past 24 MonthTable 4.1.1 Triple Bottom Line Evaluation - CSO Business AreaTable 4.1.2 Triple Bottom Line Evaluation - CSO Residential AreaTable 4.1.3 Triple Bottom Line Evaluation - Separated Sanitary AreaTable5 1 1 Unrestricted25 Year Peak Flow vs Capacity


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TABLE OF CONTENTS

LIST OF APPENDICES

Appendix 1 Basement Flooding PreventionAppendix 2 City of Lansing Storm Water ProgramAppendix 3 Model DevelopmentAppendix 4 Cost Data

a. CSOb. Hybrid Alternativec. Equalization Basin Alternatived. Pump Stationse. Wastewater Treatment Plant

Appendix 5 Emergency Bypasses

Appendix 6 Footing Drain Disconnection PlanAppendix 7 Financial Analysis

LIST OF ABBREVIATIONS/ACRONYMS

ACO Administrative Consent OrderBMP Best Management PracticeBOD Biochemical Oxygen DemandCity City of Lansing

COC Certificate of CoverageCSO Combined Sewer OverflowDO Dissolved OxygenELAC Engineering, Legal, Administration, and ContingenciesFDD Footing Drain DisconnectionGLRC Greater Lansing Regional CommitteeGPM Gallons Per MinuteHRT High Rate TreatmentIDEP Illicit Discharge Elimination Plan

I/I Inflow/InfiltrationLAPS Lansing Avenue Pump StationLBWL Lansing Board of Water and LightLID Low Impact DevelopmentMDEQ Michigan Department of Environmental QualityMDNRE Michigan Department of Natural Resources and EnvironmentMDOT Michigan Department of TransportationMG Million GallonsMGD Million Gallons per DayMS4 Municipal Separate Storm Sewer SystemNPDES National Pollutant Discharge Elimination SystemNPS Nonpoint SourceNREPA Natural Resources and Environmental Protection ActO&M Operation and MaintenancePPC Project Performance CertificationsPPP Public Participation ProcessRTB Retention TreatmentBasin


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TABLE OF CONTENTS

USEPA U.S. Environmental Protection AgencyWAS Waste Activated SludgeWMP Watershed Management PlanWWCP Wet Weather Control PlanWWTP Wastewater Treatment Plant


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1.0 EXECUTIVE SUMMARY

The City of Lansing (City) has been working to create a cleaner, greener Lansing for moreWorking to separate sewers through the Combined Sewer Overflow (CSO) program

substantial impact on the environment and the overall support of the Citys commitment to t

Since 1991, the CSO program has made sewer improvements in 72 percent of the a

combined sewers. These improvements have resulted in the reduction of 952 million gall

overflows to the rivers each year.

The Citys entire sewer system is affected by rainfall and snowmelt by increasing flow

systems. This in turn increases the potential for basement flooding and sewage overflow

and Red Cedar Rivers. Current rules for wet weather flows in the sewer system require s

and prevention of overflows from separate sewer systems, also known as Sanitary Se

(SSO). In recent years there have been more

requirements of the City as part of our storm waterPhase II permit. These three required federal programs

do not come with any grant monies and or matching

funds. Each of these wet weather programs has

regulatory program requirements, separate permits,

schedules, and compliance procedures. These separate

programs are administered by the Michigan Department

of Environmental Quality (MDEQ) and create inefficiency

and costs that are not affordable for the City sewer

customers.

The City has developed a new Wet Weather Control Plan (WWCP). This new program wi

its kind in the State of Michigan, if not the nation, to join all three unfunded mandates of the

Water Act (CSO, SSO, and storm water programs) into a coordinated approach. This WWC

ALL costs for all the programs to be spent in a responsible way that prioritizes public healt

protect the rivers and lakes using the same federal requirements, and allow the triple bott

to guide the program priorities as well. By joining the three wet weather programs into one

and encourages a plan that will work for each other. The impact of joining these three plan


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The measure of the WWCP programs success is rooted in the three bottom line factors of

Economic Environmental

Social

This triple bottom line evaluation resulted in the best and most cost-effective solutions t

problems in the sewer system. A phased approach is proposed in order to package proje

cycles. Results from each five-year cycle will be used to prioritize projects for the next

focus will be on protecting public health by preventing basement flooding. Also, improv

made to the sewer system so that it can be as efficient as possible.

The projects for the first five-year cycle (2012 to 2017) are explained in detail in Sectio

described below:

1. Basement Backup Protection Program - A program to help homeowners avoid se

and reduce footing drain overflows.

2. Siphon 11 and 12 Improvements - Increase capacity in these important siphons.

3. Tecumseh River and Frances Park Pump Stations - Provide pumping an

improvements to increase pumping capacity.

4. Emergency Bypass Facilities - Install new sewers that will allow the sewer system

wet weather flow during very heavy rainfall in order to prevent basement backups.

5. Storm Water- Continue to improve storm water quality and reduce storm water flow b

public and private green infrastructure projects. In addition, revision of the storm wate

encourage and reward the use of green infrastructure improvements in private develop

6. Combined Sewer Separation - Eliminate Regulator 033

The total cost for these proposed projects is more than $15 million for the initial five-year pl


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Long-term Wet Weather Control Plan

The recommended long-term WWCP contains a blend of projects that will:

Continue to make improvements to the existing sewer system, pump stations, an

treatment plant (WWTP) in order for it to run efficiently.

Provide temporary storage of peak flows.

Remove sources of wet weather flow through combined sewer separation anddisconnection.

Continue installation of new sewers that will allow the sewer system to bypass high we

during very heavy rainfall in order to prevent basement backups.

Recognize the importance and effectiveness of storm water projects and watershed

planning as part of the schedule and project priorities.

The estimated overall cost for the State Revolving Fund (SRF) Loan-eligible City

recommended WWCP remains a staggering $420 million. However, this is $230 million les

for the previous separate approaches to wet weather flow control.

Table 1.0 - WWCP Projec t Costs

(Capital Cost including 35% engineering, legal, administration, contingencies. ENR =8641)CSO Areas

Separation $198,547,000

Retention/Treatment Basins 52,549,000

SSO Areas

Sewer System Capacity Improvements 56,955,950

Siphon Improvements 9,315,000

Pump Station Improvements 20,043,600

Equalization Basin Improvements 30,632,600

Footing Drain Disconnection/Basement Disconnection 2,000,000

Wastewater Treatment Plant 35,630,000

Emergency Bypass Facilities 5,000,000

Storm Water 10,000,000


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The current federal requirements of the CSO, SSO, and storm water programs are costly,

include separate permits, schedules, and compliance procedures. The 2012 WWCP unif

requirements for the City by including the plans for the wastewater permit, the SSO long

well as the Citys storm water permit. During the WWCP study, a financial analysis of the im

ratepayers was completed. The costs of the long-term plan are above the near-term finan

the City. Therefore, a phased approach to implementation is required. This comprehensive

program will need to be implemented over at least a 40-year period to avoid placing

financial burden on the region and the City sewer customers.

Overall, it is critical to provide City residents a cleaner, greener community where improve

the importance of public health, while remaining cost-effective and efficient.


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Figure 1.0 - Recommended Wet Weather Control Plan


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2.0 INTRODUCTION

This report presents the basis for a holistic approach to managing wet weather flow in the (City) wastewater service area. The need for this comprehensive approach has resu

realization that the Wet Weather Control Plan (WWCP) must be affordable and support

growth of the region and not be a severe burden on the rate payers. Other factors supporti

more comprehensive approach to managing wet weather flows include the greater aw

critical importance of protecting public health by preventing basement flooding, and the fac

has clearly documented the cost effectiveness of storm water quality initiatives for the pr

rivers and streams in terms of pollutant removal costs.

The 2008 Combined Sewer Overflow (CSO) Program Evaluation Report recommends int

CSO, Sanitary Sewer Overflow (SSO), and storm water programs. Prior to this evaluation

management programs were handled independently which reduced efficiency and effe

holistic and integrated WWCP maximizes the resources devoted for controlling CSOs, SS

water discharges in a cost-effective manner. An integrated approach to meeting t

environmental, economic, and social needs of the City can be affordable while protectin

and improving water quality. The WWCP can unify the existing legal requirements

Administrative Consent Order (ACO), the National Pollutant Discharge Elimination Sy

permit, and storm water permit. A recommended schedule and sequence for the recomm

is outlined based on these goals.

The WWCP report content and organization is as follows:

Section 3 provides history on the extensive amount of work already completed by the

sewage discharges and explains the current regulatory compliance and WWCP.

A triple bottom line assessment of the economic, environmental, and social im

alternatives for the implementation of the WWCP is presented in Section 4.

Updated modeling results and information on capacity limitations in the collection syste

in Section 5.

Section 6 explains the scope and cost for various alternatives to control wet weather flo


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The proposed process for prioritization and implementation of the WWCP pro

administration of future updates to the WWCP is provided in Section 9.

The purpose of the WWCP is to provide a planning tool for the ongoing management and i

the wastewater and storm water facilities in the City service area. Significant detail is p

projects that are scheduled within the period of the current NPDES permit and the NPDES

next five-year reissuance cycle. A planning level program is provided for the remaining wo

CSO and SSO control including cost estimates and schedules. Prioritization of inves

weather control projects will be an ongoing process, which is appropriate because the be

managing wet weather flow may change as information is collected on the effectiveness

disconnection, the prevention of basement flooding, and measured impacts of syste

projects. As the program is updated and implemented, assessment of the most criti

cost-effective approaches will be completed.


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3.0 CURRENT WET WEATHER CONTROL PROGRAM ANFACILITIES

3.1 COMBINED SEWER OVERFLOW (CSO) CONTROL PROGRAM

3.1.1 1991PROJECT PLAN

A project plan to obtain funding under the State Revolving Fund (SRF) loan program wa

April 1991 and approved by the Michigan Department of Natural Resources in 1992. At th

27 percent of the City of Lansing (City) was served by combined sewers. Forty combined

discharged into the Grand River and the Red Cedar River. The project plan evaluated

control CSO and determined that combined sewer separation was the most cost-effec

Since this plan was prepared, the City has separated 72% of the combined sewer area an

average volume of combined sewage overflow by 952 million gallons annually. In additio

eliminated 25 of the 40 CSO regulators through sewer separation. The location of the r

regulators is shown on Figure 3.1., while Table 3.1.1., below, summarizes sewer se

completed to date.

Table 3.1.1 - Lansing Combined Sewer Separation Completed

Phase Segment SRF No. 5005-Area

Separated,Acres

CSO Area Separated

I 1 01 298 028, 029, 030, 031, 035, 036, 038,039, 040

I 2 02 56 043

II 1 03,04 11 Foster Avenue Sanitary InterceptorSouth and Pere Marquette Street

II 2 05, 06 156 041, Foster Avenue SanitaryInterceptor *North

II 3 07, 08 678 Area I, J , and Tollgate Drain

II 4 09 251 022 West**

II 5 10 18 Red Cedar Area K SanitaryInterceptor (by MDOT)

III 1 11 352 Northeast Sanitary Interceptor andRed Cedar Areas G and H

III 2 12 347 Moores Park Trunk Sewer and RedCedar Area K

III 3 13 211 013 South

III 4 14 276 037


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Table 3.1.1 - Lansing Combined Sewer Separation Completed

Phase Segment SRF No. 5005-Area

Separated,

Acres

CSO Area Separated

IV 5 21 573 018 Southwest, 013 Northeast, 034A,045, Downtown-Grand Avenue /Walnut Street

V 1 22 ***382 034B, 015 North, Downtown-Allegan/Chestnut 015, 034B

TOTAL 4,868

*Construction of the Foster Avenue Interceptor provided a separate sanitary sewer outlet for 347 acseparated area north of Hopkins Avenue that had been flowing into the CSO regulator 042 service a

**Separation of 022 West provided a separate sanitary sewer outlet for 96 acres of previously separhad been flowing into the CSO regulator 022 service area.

*** The indicated Area Separated for Phase V, Segment 1 reflects the total separated acreage for segment, including the 015 North Project, which is still under construction. A large percentage of theconstruction associated with the 015 North Project is already complete, and construction of the projeschedule for completion by the date indicated (November of 2011).

3.1.2 PROJECT PLANAMENDMENT NO.3

Project Plan Amendment No. 3 was prepared on behalf of the City in 2007 to continue

loans for the next five years of CSO control projects. This document concludes that se

remains the most cost-effective alternative to control CSO in Lansing. Although separat

determined to be higher in the downtown areas, this Amendment concludes that sew

remains more cost-effective than providing combined sewer relief and CSO retention. Th

includes Phase IV, Segments 4 and 5 and Phase V, Segments 1 through 3. The estimate

eligible work in these segments was $102.6 million. The estimated cost for all of the r

Control Program was $240.8 million. (ENR 7880)

3.1.4 NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)P

NPDES Permit No. MI 0023400 for the Lansing Wastewater Treatment Plant (WWTP)

December 1, 2008, and expires on October 1, 2012. Part I.A.5, Discharges from Co

Systems, permits 23 CSO outfalls in the City. The permits deadline for elimination of the r

outfalls requires completion on or before December 31, 2019, with an interim deadline fo

Outfalls 009, 010, 014, 015, 032, and 034, by December 31, 2014. Locations of the r

regulators are shown in Figure 3.1. The City may, in accordance with Part I.A.5.d. of the

seek modificationof thepermit toaddress prevailingsituations includingaffordability


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Figure 3.1 - Remaining CSO Regulators


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3.2 SANITARY SEWER OVERFLOW CONTROL PROGRAM

3.2.1 2003SANITARY SEWER SYSTEM MASTER PLAN

A Sanitary Sewer Master Plan was completed for the City in 2003. The study evaluated

control Sanitary Sewer Overflows (SSO) and basement flooding, which was believed

primarily by footing drain connections and private property inflow sources. Approximately

the 27,940 acre wastewater service area is served by separated sanitary. A model of

sewer system was developed and calibrated to determine wet weather flows and evalu

controls. The model predicted a peak 25-year, 24-hour wet weather flow at the WWTP gallons per day (MGD). The projected flow volume in excess of the WWTP secondary treat

was 113 MGD. The study evaluated a number of strategies to control SSO including trans

storage, and source removal. WWTP improvements could include additional storage vo

rate treatment (HRT) system for wet weather flow.

The recommended SSO control program consisted primarily of disconnecting footing d

26,000 homes and adding an additional 1 million gallons (MG) of storage at the WW

capacity for footing drain flows would be provided in conjunction with future combined se

projects and some pump station and sewer capacity upgrades would be provided in the se

area. The estimated capital cost for the recommended program was $373 million (

SSO control.

3.2.2 ADMINISTRATIVE CONSENT ORDER (ACO)

The City agreed to an ACO with the Michigan Department of Environmental Quality (MDE

9, 2004, to complete a program to control SSOs and basement flooding by December 31,

required submittal of an approvable long-term SSO control work plan on or before Decem

Although the City submitted the work plan in compliance with this schedule, subseq

Department of Natural Resources and Environment (MDNRE, formerly the MDEQ) review a

the work plan is on hold pending completion of this Wet Weather Control Plan (WWC

required design criteria for prevention of SSOs is for collection, storage, and treat

generated during any rainfall event less than or equal to a 25-year event, occurring dur

season and for normal soil moisture conditions. The MDEQ subsequently provided writt

that the associated design storm event for SSO control is the 25-year 24-hour prec


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3.2.3 2008CSOPROGRAM EVALUATION REPORT

An integrated consideration of the CSO, SSO, storm water, and WWTP was completed

Prior to this evaluation, the wet weather management programs for these programs

independently with an estimated capital cost of over $676 million (ENR 8641). This cost

sewer rates that exceed affordability criteria developed by the U.S. Environmental Pro

(USEPA). An alternative approach was presented that included CSO and SSO tunnels, lim

sewer separation, and footing drain disconnection. Allowances were included for sew

rehabilitation and storm water treatment. The estimated capital cost for this alternative

$639 million (ENR 8641).

Key findings and considerations from this report include:

The wet weather management program approach and regulatory compliance strat

enhanced by using an integrated program for CSO, SSO, storm water, and the WWTP

Innovative storage and treatment technologies for wet weather control should be consid

An integrated Wet Weather Control Program may reduce cost by providing more cost

of control.

The ongoing development of Total Maximum Daily Load (TMDL) implementation p

monitored to manage the effect on the City.

Although CSO separation has been found to remain the correct solution in the past, c

other CSO control facilities is warranted.

A review of the cost-effective level of protection for SSO control and emergency overf

performed, including application of a continuous simulation model.

Ongoing evaluation of the WWTP processes is necessary to evaluate both peak wet

and expected high flow duration.

Continue with a watershed-based approach for storm water management with an em

impact development (LID) techniques. A budget of at least $10 million for storm water

the next 15 years was recommended.

An integrated wet weather approach will require that the City negotiate with the MDEQ

the NPDES Permit and ACO. Preparation of an amended project plan was recommend

SRF financing.

A continuing public relations program is important to maintain communication about th


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3.3 SSO AND EMERGENCY BYPASSES

Emergency bypasses of wastewater are necessary to protect public health in respons

caused by a collapsed pipe or blockage of the sewer or when the sewer is overloaded durin

weather events. The City has used portable pumping equipment at critical locations

duration and severity of basement flooding. Locations where bypass pumping has historic

is shown on Figure 3.3.1.

The City has prepared updated procedures for notification of untreated or partially t

discharges. The document outlines statutory and regulatory requirements for notificat

discharges in accordance with Section 3112a (i.e., MCL 324.3112a) of the Natural R

Environmental Protection Act (NREPA), Act 451 of 1994, as amended. The procedure

process; specifically, an initial notification to assure compliance with statutory a

requirements, and a final report with detailed data specific to the discharge/overflow event.


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Figure 3.3.1 - Historical Bypass Pumping


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3.4 BASEMENT BACKUP PROTECTION

Sewage backups into basements create a difficult situation and can present a health and

residents. Sewer backups can lead to illness, destruction of valuables, damage to houses,

electrocution. The City is actively implementing programs to prevent basement floodin

entitled Basement Flooding Cause & Effects was prepared in March 2010 to help

understand the cause, prevention, and cleanup methods for basement flooding. The broch

for public education in response to reports of basement flooding and is available on the

Standard operating procedures (SOP) for City employees are also being updated for use

at orientation and periodic meetings.

Sewer backups can be caused by either a problem in a private sewer line lateral or in th

system. Repair and maintenance of the sewer lateral is the responsibility of the private p

Sewer backups caused by private sewer laterals commonly include: roots, broken pip

obstructing the flow. The City may be responsible for sewer backups resulting from the

sanitary system. A collapsed sewer main, blockage, or excessive wet weather flow to sewalso cause backups into basements.

The City responds to citizen reports of backups into basements. City staff investigates

occurrence and determines if the backup is caused by the private lateral or public syst

public system is surcharged, City staff takes appropriate actions in accordance with their

includes maintaining records for each reported event. Locations where property ow

basement flooding between 2007 and 2009 are shown on Figure 3.4.1.

The City is working to prevent basement flooding through ongoing sewer maintenanc

bypass pumping, public education, and training of municipal employees. The City is al

upgrading the wastewater collection system to provide capacity for wet weather flow and

basement flooding and SSOs.


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Figure 3.4.1 - Sewer Com plain ts 2007 - 2009 Repor t


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3.5 STORM WATER PROGRAM

The current storm water program in the City was developed for compliance with NPDES re

section provides a review of the current storm water NPDES permit which is based

Management Plans (WMPs) for the Grand, Red Cedar, and Looking Glass Rivers. Discus

historic water quality data and the potential impact of TMDLs are included in Appendix 2.

3.5.1 MUNICIPAL SEPARATE STORM SEWER SYSTEMS (MS4S)-GENERAL P

On March 10, 2003, any municipality within the Lansing Urbanized Area (UA) was require

NPDES Phase II storm water permit for MS4 discharges. Because of this requirem

participated in establishing the Greater Lansing Regional Committee (GLRC) that allows th

municipalities to use a watershed approach for securing the necessary storm water NPDE

committee has prepared three WMPs covering the Upper Grand River, Lower Red Ce

Middle Looking Glass River. The primary areas covering the City are the Upper Grand R

Red Cedar River. The locations of storm water outfalls in the City of Lansing are shown on

The first Certificate of Coverage (COC) under storm water General Permit No. MIG619000

the City on November 6, 2003. The Storm Water Pollution Prevention Initiative (SWPPI) re

permit was submitted on September 30, 2006.

Key components of the storm water permit involve implementing action items as specified

and reporting progress in an annual report submitted to the MDEQ. Six categories of con

are included in the SWPPI, including:

1. Public Education

2. TMDL

3. Illicit Discharge Investigations and Elimination

4. Construction Project Erosion and Sediment Control

5. Post-Construction Controls for New Development and Redevelopment Projects6. Pollution Prevention and Good Housekeeping for Municipal Operations

Combined sewer service areas are excluded from coverage under this permit until sewe

complete. As sewer separation work is completed, coverage for the new storm sewer o

dd d h i i j i i h h i l i f d d l


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Figure 3.5.1 - City of Lansing Storm Water Outfalls


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3.6 WWTP

The Lansing WWTP is composed of the North Plant and the newer South Plant. The des

existing facilities is 35 MGD. This is based on the design capacity of the secondary treat

The WWTP has seen peak flows of over 100 MGD but recent peak flows have been around

average daily flow is approximately 16 MGD.

The North and South Plants each have facilities for grit removal, primary sedimentation, flo

activated sludge biological treatment including final clarification, and chemical phospho

Facilities for screening, tertiary filtration, effluent disinfection, and solids handling are partNorth Plant that were not duplicated in the South Plant. Together, the systems provide an

of treatment for residential, commercial, and industrial wastewater prior to discharge to the

summary of unit processes is shown in Table 3.6.

3.6.2 PERMIT REQUIREMENTS

Treated and wet weather effluent from the Lansing WWTP system is discharged under MI0023400. The permit identifies three outfalls within the Lansing WWTP. Filtered and

effluent is discharged to Outfall 001A. Permit limits for this outfall vary seasonally, with th

between May 1 and November 30. During this time, the monthly limits for cBOD5, TSS, an

20, and 0.5 mg/L, respectively. The daily limits for cBOD5 and NH3-N are 10 and 2 mg/

Load limits for these parameters are based on a flow of 35 MGD. In addition, the Lan

permitted to discharge the North and South Plant Retention/Equalization Basin overflows t

002A and 003A, respectively. The fecal coliform concentrations are not-to-exceed a da

cts/100 ml and a monthly limit of 200 cts/100 ml. Other pollutants only need to be repor

from the retention basin is authorized when flows are in excess of the rated design capac

and flows at the headworks of the treatment facilities exceed 50 MGD during storm even

permit that expires on October 1, 2012, also requires the concentrations of conventional p

reported.

Table 3.6 - Lansing WWTP Summary of Uni t Processes

Treatment Step Treatment TypeCharacteristics

North South

Mechanical Bar


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Table 3.6 - Lansing WWTP Summary of Uni t Processes

Treatment Step Treatment Type

Characteristics

North South

Equalization/Retention Offline, Aboveground V =4 MG V =9 MG

Secondary

Activated SludgeAeration Tanks

4 ea. 4-pass 124 x 209 x15 SWD; 11.7 MG

5 ea. 1-pass 48 x20 SWD; V =8.1 Space provided foadditional aeratio

Activated Sludge

Settling Tanks

2 ea. 110-ft.- x 14 SWD;SA =19,000 sf, V =2.0 MG

4 ea. 90-ft.- x 9.4 SWD;SA =25,600 sf, V =2.4 MG

4 ea. 110-ft.- x SWD; SA =38,00

4.0 MGBuild-out: +2 tank

Tertiary

ChemicalPhosphorous Removal

Ferric ChloridePumping: 120 gphStorage: 20,000 gal.

Ferric ChloridePumping: 80 gph

Rapid Sand Filters14 ea. 900 sf w/sand mono-mediaSecondary effluent firm pumping capacity =75 MTertiary filter firm capacity =101 mgd

Effluent Disinfection Ultraviolet Fischer Porter UV Disinfection system

3.6.3 HISTORICAL WET WEATHER FLOWS

Dry weather flows are approximately 16 MGD. A review of two years of historic plant flow d

through May 2007) reveals that high peak hourly flows up to 70 MGD have been reco

number of storm events due to high infiltration and inflow in the collection system. This pla

listed in Table 3.6 and shown in Figure 3.6.3.1. A flow of over 100 MGD was received

during a storm event in May 2004 (note: this flow does not include a portion of flow from

Interceptor that bypassed preliminary treatment where the flow meters are located and wa

South Plant). During the two-year period, hourly flow exceeded 50 MGD on 35 occa

J une 2004 and J une 2007, including eight events when 50 MGD was exceeded for four

The peak day flow during this period was 49.8 MGD. A summary of influent flows for the 2

is shown in Table 3.6. The magnitude of future peak wet weather flows is depend

improvements to the collection system.


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Figure 3.6.3.1 - WWTP Peak Hourl y Flows and Average Daily Flow

Preliminary treatment and primary treatment capacity is 93 MGD, including recycle flow

flows above 50 MGD exceed the treatment capacity of secondary and tertiary systems and

the retention/equalization basins. If storm flows do not subside before the basins bec

necessary to bypass secondary treatment by directing basin overflow to a chlorinated disc

under current conditions, all flows entering the WWTP receive at least primary treatment a

The flows to the various unit processes are shown in the process flow diagram (Figure 6

weather flows less than 50 MGD receive secondary and tertiary treatment and UV disinfect

In anticipation of storm flows, treatment plant operators take the following steps to impr

high-strength and odorous first-flush materials and to optimize wet weather treatment overa

Dewater equalization/retention basins

S t d it l t l ti t ti l


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Once flow subsides, equipment is set back on auto operation and flow captured in the equ

is pumped back to secondary treatment. According to plant staff, handling of excess grit tha

in the grit tanks and primary clarifiers during storm events periodically causes maintenancgrit and sludge conveyance equipment. Based on recent plant performance, treatment p

have successfully managed storm flows without violating permit requirements. For exa

ammonia is maintained safely below permit limits even on days when high rates of in

recorded (Figure 3.6.3.2). Average effluent characteristics for the two-year period,

Table 3.6.3.2, indicate that the Lansing WWTP provides a high-level of treatment overall.

Figure 3.6.3.2 - Peak Hour ly Flow s and Effluent NH3-N


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Table 3.6.3.2 - Lansing WWTP Treated Effluent Characteristi cs for the Past 24 Months

Month/Year

EffluentFlow

CBOD5 NH3-N TSS TPFecal

Coliform

(MGD) (mg/L) (#/100 mL)

J une 2005 15.86 1 0.121 0.5 0.471 2

J uly 2005 15.27 2 0.089 0.7 0.997 2

August 2005 13.27 1 0.072 0.6 0.846 1

September2005

13.09 1 0.079 1.0 0.620 3

October 2005 11.38 1 0.043 1.2 0.350 3

November2005 13.21 1 0.049 0.7 0.312 4December2005

12.94 1 0.082 0.5 0.310 13

J anuary 2006 21.20 1 0.076 0.5 0.452 10

February 2006 19.66 1 0.045 0.4 0.496 21

March 2006 21.16 1 0.061 0.4 0.511 8

April 2006 16.72 1 0.047 0.3 0.479 4

May 2006 20.90 1 0.096 0.4 0.518 5

J une 2006 14.25 1 0.056 0.4 0.723 1

J uly 2006 13.58 1 0.091 0.3 0.733 3

August 2006 14.69 1 0.065 0.3 0.824 4

September2006

14.06 1 0.051 0.2 0.746 3

October 2006 14.98 1 0.051 0.3 0.763 3

November2006

16.01 1 0.054 0.4 0.409 4

December2006

19.68 1 0.057 0.3 0.303 7

J anuary 2007 19.71 1 0.036 0.4 0.307 6

February 2007 14.72 1 0.033 0.5 0.638 2

March 2007 21.54 1 0.078 0.5 0.274 7

April 2007 20.64 1 0.034 0.4 0.255 3

May 2007 18.86 1 0.046 0.5 0.318 4

Average 16.56 1.04 0.063 0.49 0.53 5.13


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4.0 TRIPLE BOTTOM LINE

A triple bottom line evaluation considers the social, economic, and environmental imp

weather control strategy. Basement flooding presents social impacts on public health and

lead to illness, destruction of valuable possessions, and damage to houses. Sewage di

direct environmental impacts to the receiving stream. Sewage overflows and untreated st

degrade the water quality of the Grand River and the Red Cedar River. Sewer separation

economic consequences when they disrupt businesses and residential services. Excess

increases impact economic growth and the available income of rate payers. Imple

operation factors have a direct link to long-term cost. These are just some examples

environmental, and economic factors that were taken into consideration when evaluatin

control alternatives. The cost effectiveness of the alternative strategies based on capital an

is evaluated separately in this report.

A triple bottom line evaluation was applied to compare the benefits of peak flow equaliz

Footing Drain Disconnection (FDD) and transport/treat in separated sewer areas anCombined Sewer Overflow (CSO) Retention Treatment Basins (RTB) to sewer separatio

sewer areas. The evaluation also recognized the benefits may be different in residentia

areas. Implementation and operation factors were also considered in the evaluation. W

importance of each factor was applied. Either a numeric or a positive/negative value was a

factor and were summed to provide a composite score.

It is necessary to schedule and coordinate the projects required under all the current regula

into a holistic and integrated program in order to adequately meet and balance the social,

environmental issues resulting from wet weather flow. The projects should be prioritiz

maximum effectiveness with an emphasis on protecting public health. The overall

implementation plan must be responsive to the affordability of the projects to prevent puttin

financial burden on the City sewer customers. Recognition of the cost effectiveness of th

benefits that result from investments in storm water projects is important to achienvironmental benefits from the Wet Weather Control Plan (WWCP). Tables 4.1.1 throug

examples of some of the issues that were considered in this Triple Bottom Line ev

evaluation process is consistent with the content of a project plan submittal for State R

(SRF) funding where relevant environmental and social issues are identified in the proje


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reliability of FDD source control lowered the total score for this alternative in the separate

Tables 4.1.1 through 4.1.3 present the results of the Triple Bottom Line evaluation.

Table 4.1.1 - Triple Bottom Line Evaluation - CSO Busi ness Area

Alternat ive

Weight Impact Separation Environmental Evaluation (+,0,-) Rating Score

Storm Water Treatment 30 8.1 0 0.0

Green Solutions Opportunities 30 8.1 + 8.1

Water Quality 30 8.1 + 8.1 Score (Range -19.4 to 19.4) 16.2

Each category is rated "+" (positive impact), "-" (negative impact), or "0" (no impact). The score is th

the negative impact value for a "-, or zero for a "0. The alternative score is then the sum of the scorWeight Impact Separation

Social Evaluation (+,0,-) Rating Score Long-Term Impacts

Housing and Property Value 20 5.4 + 5.4

Health and Safety 20 5.4 + 5.4

Private Inflow Cost to Property Owner 10 2.7 - -2.7 Visual Aesthetics 10 2.7 + 2.7

Odor 10 2.7 0 0.0

Historical Preservation 10 2.7 0 0.0 Short-Term Impacts

Employment and Income 20 5.4 + 5.4

Traffic Impacts 30 8.1 - -8.1

Noise 10 2.7 - -2.7

Business Disruption 30 8.1 - -8.1 Score (Range -50 to 50) -2.7

Each category is rated "+" (positive impact), "-" (negative impact), or "0" (no impact). The score is ththe negative impact value for a "-, or zero for a "0. The alternative score is then the sum of the scor

Weight Impact Separation

Implementation & Operation Factors (0-10)Constructability 20 5.4 8.0

Easements & Land Acquisition 20 5.4 10.0 Reliability 20 5.4 10.0

Maintenance Requirements 20 5.4 10.0

Flexibility 10 2.7 10.0 Operational Ease 20 5.4 10.0 Score (Range 0 to 30.6) 28.6

The best alternative in each category is awarded a 10. All others are then compared to the best. Exa

constructability of Alt. 2 is 85% of Alt. 1, it would receive an 8.5. Multiple alternatives can score a 10 Composite Alternative Scores

Separation

42.2


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Table 4.1.2 - Triple Bot tom Line Evaluation - CSO Residential Area

Weight Impact Separation Environmental Evaluation (+,0,-) Rating Score

Storm Water Treatment 30 8.11 0 0.0 Green Solutions Opportunities 30 8.11 + 8.1

Water Quality 30 8.11 + 8.1 Score (Range -19.4 to 19.4) 16.2


Weight Impact Separation Social Evaluation (+,0,-) Rating Score Long-Term Impacts

Housing and Property Value 20 5.41 + 5.4

Health and Safety 20 5.41 + 5.4 Private Inflow Cost to Property Owner 10 2.70 0 0.0 Visual Aesthetics 10 2.70 + 2.7

Odor 10 2.70 0 0.0

Historical Preservation 10 2.70 0 0.0 Short-Term Impacts

Employment and Income 20 5.41 + 5.4 Traffic Impacts 30 8.11 - -8.1

Noise 10 2.70 - -2.7

Business Disruption 30 8.11 0 0.0 Score (Range -50 to 50) 8.1


Weight Impact Separation Implementation & Operation Factors (0-10)

Constructability 20 5.41 8.0

Easements & Land Acquisition 20 5.41 10.0

Reliability 20 5.41 10.0 Maintenance Requirements 20 5.41 10.0

Flexibility 10 2.70 10.0 Operational Ease 20 5.41 10.0 Score (Range 0 to 30.6) 28.6

The best alternative in each category is awarded a 10. All others are then compared to the best. Exaconstructability of Alt. 2 is 85% of Alt. 1, it would receive an 8.5. Multiple alternatives can score a 10

Composite Alternative ScoresSeparation

53.0


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Table 4.1.3 - Triple Bot tom Line Evaluation - Separated Sanitary Area

Weight Impact FDD Transport & Environmental Evaluation (+,0,-) Rating Score Rating S

Storm Water Treatment 30 8.11 0 0.0 0 Green Solutions Opportunities 30 8.11 0 0.0 0

Water Quality 30 8.11 + 8.1 +Score (Range -19.4 to 19.4) 8.1 8.1

Each category is rated "+" (positive impact), "-" (negative impact), or "0" (no impact). The score is th"+, the negative impact value for a "-, or zero for a "0. The alternative score is then the sum of the

Weight Impact FDD Transport & Social Evaluation (+,0,-) Rating Score Rating SLong-Term Impacts

Housing and Property Value 20 5.41 + 5.4 +

Health and Safety 20 5.41 + 5.4 +Private Inflow Cost to Property Owner 10 2.70 - -2.7 0 Visual Aesthetics 10 2.70 0 0.0 +

Odor 10 2.70 0 0.0 0

Historical Preservation 10 2.70 0 0.0 0 Short-Term Impacts

Employment and Income 20 5.41 + 5.4 +Traffic Impacts 30 8.11 0 0.0 - -

Noise 10 2.70 0 0.0 - -

Business Disruption 30 8.11 0 0.0 - -Score (Range -50 to 50) 13.5 0.0

Each category is rated "+" (positive impact), "-" (negative impact), or "0" (no impact). The score is th"+, the negative impact value for a "-, or zero for a "0. The alternative score is then the sum of the

Weight Impact FDD Transport & Implementat ion & Operation Factors (0-10)

Constructability 20 5.41 0.0 8.0

Easements & Land Acquisition 20 5.41 10.0 10.0

Reliability 20 5.41 5.0 10.0 Maintenance Requirements 20 5.41 7.0 10.0

Flexibility 10 2.70 8.0 10.0 Operational Ease 20 5.41 8.0 10.0 Score (Range 0 to 30.6) 18.4 28.6

The best alternative in each category is awarded a 10. All others are then compared to the best. Exaconstructability of Alt. 2 is 85% of Alt. 1, it would receive an 8.5. Multiple alternatives can score a 10

Composite Alternative ScoresFDD Transport &

40.0 36.8


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5.0 WET WEATHER MANAGEMENT - CAPACITY NEEDSASSESSMENT

The adequacy of the wastewater collection and treatment system was evaluated for the g

25-year, 24-hour event as presented in the Administrative Consent Order (ACO). The AC

collection and treatment system capacity must convey all rainfall events up to and includ

event during the growing season with normal soil moisture. Previous studies evaluated pe

flows for both the growing and dormant conditions and concluded that the collectio

deficiencies. Capacity needs for the Wet Weather Control Plan (WWCP) are evaluate

combined and separated sewer portions of the City of Lansing (City) based on provi

capacity for the 25-year event during the growing season with normal soil moisture. Im

address the capacity needs are analyzed in Section 6 and presented as recommended im

Section 7.

5.1 HYDRAULIC MODEL DEVELOPMENT

The Citys computer model has been developed and updated since the late 1980s and m

concerning the computer model history and development is included in Appendix 3.

separation projects have been completed since the system-wide monitoring program wa

2004. Therefore, the model has been updated to include recent sewer separation im

Combined Sewer Overflow (CSO) areas 013, 018, 020, 023, 025, 044, and 045. In additi

sewer separation plans for the remaining CSO areas were incorporated.

The additional pipes required revising sewersheds which generate dry and wet weather f

weather flows (both sewage and groundwater infiltration) were redistributed based on a

match the previous calibrated model (i.e. a comparison of the previous model results wit

model results are presented in Appendix 3).

Wet weather flows for revised sewersheds were determined based on Project Performan

(PPC) results and previous RTK parameters. At this time, no future development or lan

were evaluated because of the uncertainty associated with locations and schedule.

5.1.1 CONVEYANCE SYSTEM CAPACITY


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In general, the model includes sanitary sewers that are 12-inch diameter and larger. 8-in

sanitary sewers are not expected to have wet weather capacity issues based on compla

City staff observations, and a pipe length analysis. The pipe length analysis assumed 8-inpipes are at minimum slope, the peak flow is 4.0 gallons per minute (GPM) per parcel, the

frontage per parcel is 70 feet, and parcels on both sides of the road contribute flow. Th

estimated pipe length (8-inch equals 3,000 feet and 10-inch equals 4,500 feet) for determin

pipe may be under capacity. This analysis was completed for SSES Areas A, F and H.

The unrestricted 25-year peak flow versus capacity at critical locations is presented

Sanitary sewers with capacity deficiencies are identified based on surcharge results and th

the deficiency is presented based on a comparison to unrestricted peak flows. The unrestri

2005 Model was limited by the Lansing Avenue pumping capacity, which then forced mo

the Westside Interceptor. The 2010 Model did not include pumping restrictions, which is r

the increased flow at Lansing Avenue Pump Station (LAPS), Siphon 3, and Siphon 11. T

differences occur at Harton Street Pump Station and HH North because additional g

information (historic flow monitoring data) was used to update the RTK parameters.

Table 5.1.1 Unrestric ted 25-Year Peak Flow vs. Capacity

Capacity, MGD2010 Model,

MGD2005 Mod

MGD

Wastewater Treatment Plant 100 189.1 176.7

LAPS 66.5 93.4 69

Westside Interceptor 65 81.8 90.6Frances Park Pump Station 12.7 29.9 32.5

WWTP Pump Station 8.7 15.8 17.1

Tecumseh River Pump Station 4.8 8.8 9.2

Harton Street Pump Station 27.3 33.6 60.3

Siphon 3 51.1 67.8 45

Siphon 11 33.3 60.9 49.2

Siphon 12 7.6 16.8 16.6HH North 8 13.8 5.2

HH South 11.4 12.6 15


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Figure 5.1.1 - System Surcharge


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6.0 WET WEATHER CONTROL ALTERNATIVES - ANALY

An analysis of improvement alternatives to manage wet weather flow in the wastewater

treatment system was completed. The work completed in prior studies and project plan am

reviewed. The objectives for the wet weather control alternatives are to maximize the contr

Sewer Overflows (CSOs), Sanitary Sewer Overflows (SSOs) and storm water dis

cost-effective manner. Section 5 presents the feasible alternatives that were evaluated in

the estimated capital and present worth cost. Capital costs (construction cost plus 35% fo

legal, administration, and contingencies [ELAC]) for the alternatives are presented using a

6841 (December 2009). Analysis of the improvement alternatives must also consider

environmental impacts of the control strategy. The discussion of a triple bottom line

considers economic, social, and environmental issues is included in Section 6.

6.1 BALANCED SYSTEM APPROACH

The existing City of Lansing (City) wastewater collection system has numerous locations

limitations restrict the ability to utilize the full available capacity of the main interceptors

weather flow. The focus of the balanced system approach involves the identification of the

and determining the improvements needed to optimize the conveyance of upstream flows

facilities. The overall goal is to maximize conveyance of the 25-year, 24-hour growing sea

Wastewater Treatment Plant (WWTP). When capacity is not available to achieve that g

improvements have been identified. The City has two large interceptors (Central and

convey flow to the Lansing Avenue Pump Station (LAPS) and WWTP. All flows are pumpe

headworks and the pumping capacity is approximately 135 million gallons per day (MGD).

peak flows greater than 120 MGD have been observed by City staff during wet weather eve

The balanced system approach attempts to maximize the peak wet weather flow t

Alternatives for managing wet weather flows at the WWTP are discussed in Sect

investigation to eliminate bottlenecks in the wastewater collection system identified serestrictions. These restrictions result from inadequate pump station or siphon capacity wh

upstream and downstream trunk sewers have adequate capacity. Removing these b

increase the flows to the WWTP. These bottlenecks are presented in Figure 6.1 and includ


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Figure 6.1 - Collection System Capacity


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6.2.1.1 PRELIMINARY ANALYSIS OF COMBINED SEWER AREAS

Preliminary analysis found sewer separation to be the obvious cost-effective solution fo

sewersheds. This analysis built upon the 2008 CSO Evaluation Report findings. The analy

the amount of storage (treatment shafts), relief/transport sewers, road rehabilita

improvements, and sewer separation costs. The analysis completed as part of the

considered treatment shafts as the selected RTB facility.Sewersheds in which large areas are already separated are generally not conducive to app

facilities because the size of the basin required is disproportionate to the work of separating

sewer system. The regulator areas where the preliminary analysis found the obvious

solution to be separation, all have the characteristic of being partially separated.

The following identifies specifics for each of the six areas where a financial analysis of an R

was not prepared. Regarding four of these areas, the alternatives analysis conducted as p

CSO Evaluation Report indicated a significant disparity between the associated sewer se

and RTB costs, so a new financial analysis was not prepared (see below).

Regulator 015: Sewer Separation $14 million, RTB $18 million (2008 CSO Evaluation R

Regulator 019: No budget prepared. A 62-inch combined sewer, which includes storm

015 sewershed is tributary to the regulator. Due to the huge disparity of separated

combined sewer area within the sewershed, engineering judgment found that an RTB

sense.

Regulator 021: Sewer Separation $7 million, RTB $13 million (2008 CSO Evaluation Re


Regulator 033: No budget prepared. All known sanitary sewer sources within the 0

have been removed through the demolition of facilities. Thus, the sewershed is s

anticipate new sanitary sewers will be constructed as part of future redevelopment.



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operation and maintenance (O&M) of the collection system and WWTP, environmenta

public health benefits.

City collection system improvements include the construction of new water-tight sanita

rehabilitation and upgrades to the existing sewers that remain in the rebuilt system. The re

upgrades of the existing system ensure that all sanitary sewers are structurally sound a

Furthermore, the rehabilitation ensures that all storm sewers are structurally sound.

Infrastructure improvements are a part of every sewer separation project. Most notably, the

advantage of the new sewer construction to reconstruct the impacted streets. This appinfrastretching, has resulted in leveraging sewer construction funds to offset road reconst

great advantage. Road improvements have also addressed City traffic calming efforts. In a

infrastructure, the City has leveraged the separation projects to facilitate other C

non-City-owned infrastructure improvements. This additional infrastructure includes

sidewalks, and other utilities, to name a few.

The Lansing WWTP and O&M operations may benefit from sewer separation. When comp

approach, sewer separation will result in reduced flow to the WWTP and less di

Furthermore, when comparing RTBs to sewer separation, the latter has lower O&

environmental and public health benefits of combined sewer separation result in less

discharged to the river.

Fifteen CSO regulators are currently in operation within the Citys combined sewer colCombined sewer separation was evaluated as an alternative for control of CSO for th

regulator sewersheds. The analysis uses a separation approach consistent with rece

separation project practices. An opinion of present worth cost of all remaining regulator s

been calculated based upon historical City sewer separation costs.

The combined sewer separation alternative includes the complete separation of sewe

remaining combined sewershed. Standard practice is to construct new sanitary sewers a

generally larger combined sewer pipes to storm sewers. The construction of new s

provides a tight system with minimal infiltration. Capacity increases are included when req

the existing regulator and the receiving interceptor sewer. Sewer separation design is base


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Table 6.2.1.3 - RTB Sizing Data

Subcatchment10-year/1-hour

Peak FlowFooting Drain

Flow

Flow Rate (cfs) Flow Rate (cfs) RTB Size (MG)008 227.8 5.13 3.0

009/012 297.65 12.01 3.8

016/017 111.28 1.86 1.5

024/046 154.32 2.80 2.0

026 28.66 3.33 0.3

032 327.58 16.50 4.2

6.2.1.4 CSOCONTROL COST ESTIMATES

The methodology for calculation of capital and present worth costs for the CSO contro

included in Appendix 4a. Table 6.2.1.4 presents the City capital and present worth costs for

sewer separation and RTB alternatives.

Table 6.2.1.4 - CSO Cont rol Al ternative Cost Esti mates

Regulator ENR = 8641 (December 2009)Alternat ive #1 Alternat

SewerSeparation

RT

REG-008 City Capital Cost $22,030,000 $28,

City Adjusted Present Worth $16,473,000 $24,

REG-009/012 City Capital Cost $41,515,000 $40,










REG-026 City Capital Cost $7 494 000 $10


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Table 6.2.1.4 - CSO Cont rol Al ternative Cost Esti mates

Regulator ENR = 8641 (December 2009)Alternat ive #1 Alternat

SewerSeparation

RT

REG-034D City Capital Cost $11,928,000 NA

City Adjus ted Present Worth $8,910,000 NA

REG-015S City Capital Cost $18,216,000 NA


REG-019 City Capital Cost $7,502,000 NA






6.2.2 SSOCONTROL

Alternatives to prevent SSO and basement flooding include optimizing the use of the existin

to convey wet weather flow to the WWTP, providing storage for equalization of peak flow r

treatment capacity, and removal of the source of wet weather flow by disconnecting foot

following section presents the results of the analysis of these wet weather control altern

originating from the separated sewer system. The analysis is based on providing capacity

24-hour growing season event.

6.2.2.1 BALANCED SYSTEM APPROACH

The existing City collection system has numerous locations where capacity limitations restr

utilize the full available capacity of the main interceptors to convey wet weather flows

Capacity improvements at the following locations will balance upstream and downstream

reduce basement flooding, and are consistent with the overall goals of the Wet Weathe

(WWCP).

Tecumseh River Pump Station (TRPS)

Frances Park Pump Station


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Table 6.2.2.1 - Force Main and Pump Station Design Flows

PumpStation

Pump

StationRatedCapacity

(MGD)

Force

MainDiameter

(in)

ExVelocity(fps)

FutureFlow(MGD)

Pump

StationCapacityDeficiency

(MGD)

Future

ForceMainDiameter

(in)

FutureVelocity(fps)

TRPS 4.8 16/12 9.5 9.0 4.2 24 4.4

FrancesPark

12.7 24 6.3 16.0 3.3 24 7.9

WWTP 8.7 20 6.2 16.0 7.3 24 7.9

Rivers Edge 1.3 16 1.4 4.0 2.7 4.4

Willard 1.5 12 3.0 3 1.5 5.9

Ravenswood 0.7 8 3.1 2.4 1.7 12 4.7

6.2.2.2 PEAKFLOW EQUALIZATION

Peak wet weather flow equalization limits the downstream flow rate to the capacity of the

treatment facilities. The flow in excess of the downstream capacity is temporarily sto

dewatered as soon as capacity in the collection system and/or the WWTP is available. A

weather event may cause the storage facility to fill and bypass excess flow to a receiving s

facilities for peak flow equalization may consist of tunnels, treatment shafts, or storage ba

be above grade facilities where the peak wet weather flow must be pumped in and they are

gravity or a below grade basin that fills by gravity and uses dewatering pumps. The cos

peak flow equalization in this report assumes that storage will be provided by below grade s

The wet weather flow will enter the storage basin by gravity and pumps will dewater t

downstream capacity is available. The proposed storage basin sites are located where

conveyance or treatment capacity is less than the peak flow associated with 25-year, 24

season conditions. The final storage approach will be determined during design and wil

soil, groundwater, and site constraints.

Two system-wide approaches for peak wet weather flow equalization were co

Hybrid Alternative and the Regional Equalization Alternative. The proposed equalization b

capacities for the Hybrid Alternative were based on first optimizing the use of the available

existing sewer system Bottlenecks in the wastewater collection system such as restriction


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The Regional Equalization Alternative places much higher reliance on regional storage

though all of the available transport capacity of the existing sewer system and intercepto

used. Storage locations and capacities for the Regional Equalization Alternative a

Figure 6.2.2.2.

An estimated cost for the regional equalization basins was developed based on recent b

Appendix 4b includes the basis for the estimated cost of the Hybrid Alternative. The est

costs for the Hybrid Alternative are included in Table 6.2.2.2(a). Appendix 4c includes th

estimated cost of the Regional Equalization Basin Alternative. The estimated cost for the

Regional Equalization Alternative are shown in Table 6.2.2.2(b).

Table 6.2.2.2(a) - Hybrid Alt ernative - Project Cost Summary

AreaSewer System

CapacityImprovements

SiphonImprovements

Pump StationImprovements

EqualizationBasin

Improvements

Estim

A $5,451,300 $0 $1,924,900 $0 $

C 7,771,950 0 7,260,300 0

H 19,975,950 0 6,129,000 10,830,400

HH North 789,750 0 0 10,830,400

HH South 5,248,800 135,000 0 0

F 7,337,250 0 0 4,485,900

SP 7,915,050 4,387,500 0 4,485,900

SLI 239,750 4,792,500 4,729,400 0

L 1,335,150 0 0 0

CI 891,000 0 0 0

Total Cost $56,955,950 $9,315,000 $20,043,600 $30,632,600 $1

(Capital Cost including 35% engineering, legal, administration, contingencies. ENR=8641)


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Table 6.2.2.2(b) - Regional Equalization Bas in Alternative Cost Summary(Capital Cost including 35% engineering, legal, administration, contingencies. ENR=8641)

AreaSewer System

Capacity

Improvements

Pump StationImprovements

Equalization BasinImprovements

E

A $4,661,550 $0 $5,508,000

C 2,208,600 4,911,300 8,971,800

H 15,234,750 3,307,500 18,610,600

HH North 1,574,100 0 0

HH South 3,719,250 0 11,030,200

F 7,337,250 0 4,485,900

SP 1,498,500 0 15,516,100

SLI 240,300 4,729,400 6,544,300

L 1,335,150 0 0

CI 891,000 0 0

Total Cost $38,700,450 $12,948,200 $70,666,900


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Figure 6.2.2.1 - Hybrid Alternative

Fi 6 2 2 2 R i l E li ti Alt ti


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Figure 6.2.2.2 - Regional Equalization Alternative

6 2 2 3 SO C R O FOO G D D SCO C O (FDD)


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6.2.2.3 SOURCE REMOVAL -FOOTING DRAIN DISCONNECTION (FDD)

The goal of the FDD Program is to cost-effectively remove Inflow/Infiltration (I/I) from the

collection system. The FDD Program will be considered as part of the overall WW

sewershed areas within the City where data supports the application of FDD as a cost-effec

A review of the historic building construction data within the City shows a correlation bet

when homes were constructed and footing drain flow to the sanitary sewer. Figure 6.2.2

building construction era information. Homes constructed between 1940 and 1959 have

have the highest contribution of footing drain flow to the sanitary sewer system.

Figure 6 2 2 3(a) Building Construction Era


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Figure 6.2.2.3(a) - Building Construction Era

Phase 1 of the program is to develop and evaluate the overall approach while using select


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Phase 1 of the program is to develop and evaluate the overall approach while using select

[Figure 6.2.2.3(b)] where enough homeowners volunteer to participate by accomplishing

property. As part of the Phase 1 program, the costs, performance, benefits, risks, and othe

documented and used to guide the City in its development of subsequent FDD phases.

Figure 6.2.2.3(b) - FDD Target Areas

The FDD program will have the following components:

Determine candidate neighborhood areas

Pre-disconnection flow monitoring and performance documentation

Identify volunteer participation properties and select final target Phase 1 sewersheds

Disconnection design and implementation

Post-disconnection flow monitoring and performance documentation

Observations and data collected during Phase 1 of the FDD work will be used to assess th

6 2 3 EMERGENCY BYPASSES


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6.2.3 EMERGENCY BYPASSES

The construction of permanent facilities to allow emergency bypasses is necessary be

pumping equipment is often not a feasible strategy to prevent flooding of basements. Thfact that the sewer system often surcharges during intense rainfall events before the pump

can be mobilized and placed into operation. Simply reducing the duration of sewer surcha

not significantly reduce the cost and public health impacts associated with basement floodin

It is inevitable that a wet weather event will occur that will exceed the capacity of a wastew

system or treatment plant. Emergency bypasses of wastewater are necessary to protect pu

safety when collapsed pipes, blockage of the public sewer system, or excessive wet w

sewer mains may cause basement flooding. They are a critical strategy to protect public h

WWCP is implemented. They also allow a cost-effective basis of design for improveme

weather program facilities by allowing the basis of design for new facilities to meet or minim

compliance requirements. Additional protection for public health is realized by bypassi

before sewer surcharges cause basement flooding.

The emergency bypass facility should meet two key design criteria: first, the time and volu

will need to be measured. Second, the overflow will require a mechanical device (i.e. pump

gate etc.) be installed to separate the storm and sanitary system and control whether b

This would help prevent accidental overflows or backflow into the sanitary sewer system.

of an acceptable outlet would be a key component of the design. Typically, flow will on

diverted during a large storm when the existing storm sewer system may already be near it

hydraulic grade line of the storm sewer or receiving stream will need to be analyzed to d

overflow can discharge by gravity. If the hydraulic grade line of the system does not a

discharge, a pump station would be required. Also, the design will need to ensure that storm

backflow into the sanitary sewer system.

The basis of design for an emergency bypass would depend upon the potential upstrea

flow and the available downstream capacity. The facility could be modified or eliminated i

other improvements are completed that would affect the collection system hydraulic

Figure 6.2.3 shows possible future locations where the installation of emergency bypass

help supplement other wet weather control improvements, such as equalization/storage

Figure 6.2.3 - Emergency Bypass Locations


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g g y yp

6.2.4 BASEMENT BACKUP PREVENTION


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A flooded basement creates one of the most difficult situations a home owner deals with a

public health and safety issue for residents. Sewer backups can lead to illness, destrvaluables, damage to your house, and the risk of electrocution. The MDEQ has indic

protection of public health is their highest priority. The City is actively implementing progra

basement flooding. A brochure entitled Basement Flooding Cause & Effects was prepared

to help homeowners understand the cause, prevention, and cleanup methods for basemen

brochure is available for public education in response to reports of basement flooding and

the City website. Standard operating procedures (SOP) for City employees are also beinuse in training staff at orientation and periodic meetings.

A program for disconnecting basements with recurring flooding problems from a direct gra

to the sanitary sewer is recommended. This would provide an immediate and long-term

property owner. The specific approach to disconnecting the basement will be determined o

basis and could include elimination of basement service, installation of a check valve, or i

grinder pump. This would allow the public sewer to surcharge without backing up into b

were disconnected. It can avoid the need for implementing expensive sewer improvem

benefit a few homes. The basement disconnect will also include installation of a sump pu

the footing drain connection and reduce wet weather flow to the sanitary sewer.

These basement flooding prevention alternatives could be implemented by the City for

history of flooding problems. The basement disconnection program would include a pu

component, financial and technical support for homeowners, and a certification process

work was completed. The cost to disconnect basements could range from approximatel

check valve and sump pump to $12,000 to install a grinder pump.

6.2.5 WWTP

The objective for WWTP alternative development is to provide a cost-effective combinatio

and storage of future wet weather flows and loads to meet the current and anticipated

National Pollutant Discharge Elimination System (NPDES) permit limits. This evaluation

following activities:

Analysis of Design Storm Ev ent


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Lansing WWTP treatment needs were evaluated to support treatment of increased sewa

WWTP following wet weather control improvements in the wastewater collection system

estimate flow to the WWTP following the elimination of existing hydraulic bottlenecks was

various storm events. Figure 6.2.5.1 presents the hydrograph for the 25-year, 24-hour

assess necessary improvements at the WWTP.

It should be noted that the hydrograph does not include the 13 MG of existing storage c

plant. The peak instantaneous flow of 150 MGD is predicted to exceed the primary treatm

93 MGD rate for 10.5 hours duration during the storm event. Experience has shown the

primary treatment facilities can process flows of 100 MGD for up to 48 hours. Analysi

hydrograph was completed to estimate the treatment and/or storage capacity necessary

storm event. This analysis indicates a total storage capacity of 33.6 MG is required for th

hour storm event, or 20.6 MG in addition to the 13 MG of existing storage capacity.

Figure 6.2.5.1 - WWTP Hydrograph


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Al ternat ives Development

Improvements at the WWTP are necessary to provide adequate treatment capacity for th

event. It is impractical for the WWTP secondary treatment to be expanded beyond 50

when the current dry weather average daily flow averages 16 MGD. Secondary biological s

capable of maintaining a viable microorganism population capable of treating wide variation

As a result, options for expanding the current plant secondary treatment capacity beyond

not considered. However, physical process capacity for processes such as scree

sedimentation, and filtration can be increased to address wet weather flows and were i

evaluation

The alternatives identified and evaluated include:


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1. Provide HRT facilities at the WWTP for treatment of flows in excess of 50 MGD.

2. Provide added flow equalization and increase WWTP secondary capacity to 50 MGD.

The general approach to treatment for the design event was to maximize primary a

treatment at the WWTP and provide either HRT or equalization to manage the peak storm

equalization alternative, the stored flow would receive secondary treatment following th

when WWTP influent flow decreases, while for the HRT alternative, the wet weather f

receive chemically enhanced primary treatment.

A flow schematic of the existing WWTP is shown in Figure 6.2.5.2 The figure includ

capacities for each existing unit process that were used as a basis for alternative dev

capacity improvements.

Figure 6.2.5.2 - Process Diagram


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In addition, other WWTP improvements will be needed to reliably treat increased flow

li i i f CSO i h ll i S l i h i i


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elimination of CSOs in the collection system. Several unit processes that require improv

primary sedimentation, sludge thickening, sludge dewatering, and secondary sediment

improvements to the tertiary filters will provide added capacity for treatment of secondary e

filtered effluent is consistently low in Biochemical Oxygen Demand (BOD) and Total Sus

(TSS).

The following specific WWTP improvements will be needed to provide increased, rel

capacity to support either HRT or an equalization basin to capture and treat the 160 M

during the 25-year, 24-hour storm event:

Rehabilitate primary settling tanks 17-24

Provide chemical feed for enhanced primaries

Eliminate co-settling in primary clarifiers

Rehabilitate former digester as a waste activated sludge (WAS) storage tank

Install new WAS piping to digester

Install new belt filter press

Construct one new 110-foot diameter secondary clarifier (North plant)

Additional improvements at the WWTP must be constructed to store and treat excess

25-year, 24-hour storm that exceed the expanded plant capacity. Those added impro

include the construction of a 67 MGD HRT system including a lift station, screening, an

Alternately, a new 20.6 MG equalization basin can be constructed to capture WWTP flow50 MGD secondary treatment capacity.

Due to the high flow rates during the design storm event, the plant headworks capacity o

be exceeded. Therefore, when evaluating both HRT and equalization alternatives, flow from

interceptor will be received by a new pump station at the WWTP where the excess flow wi

the HRT or to a new equalization basin. The location of the new west side interceptor pum

20.6 MG equalization basin are shown on Figure 6.2.5.5.

The construction cost to provide HRT, equalization, and WWTP treatment improvements

Appendix 4e and are as follows:

will allow effluent blending. Pilot testing of HRT is recommended if this option is to be co

future The equali ation basin alternati e pro ides the highest le el of treatment necessa


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future. The equalization basin alternative provides the highest level of treatment necessa

existing NPDES permit limits and has the lowest capital cost.

Figure 6.2.5.3 - Process Diagram with HRT

Figure 6.2.5.4 - Process Diagram with 23 MG Equalization Basin


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Figure 6.2.5.5 - WWTP Sewers and Basin


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6.2.6 STORM WATER MANAGEMENT


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The City has developed a Storm Water Pollution Prevention Initiative (SWPPI) cons

Watershed Management Plans (WMP) prepared by the Greater Lansing Regional Commcompliance with the Municipal Separate Storm Sewer System (MS4), General Permit. As a

is accomplishing management practices to control the source of pollutants. This inclu

implement pollution prevention and good housekeeping activities for City facilities and

operations. Additional practices deal with public education and involvement, illicit discharge

removal, construction erosion and sediment control, and site development requirements to

construction management practices.

In addition, the City has successfully obtained grant monies to install rain gardens as

construction projects in the downtown area (Michigan Avenue and Washington Square). Th

capture storm water runoff from the street pavement area and provide filtration using veg

media placed over an underdrain system.

The City will be required to evaluate the effectiveness of the control activities described athe annual reporting and permit renewal requirements of the NPDES General Permit.

SWPPI will need to be updated and revised based on this information. Therefore, the prim

treating storm water runoff should be to achieve compliance with the permit requirement

discharge of pollutants to the maximum extent practical and consistent with the Grand Riv

River, and Looking Glass River WMPs. Opportunities to accomplish this should include t

Impact Development (LID) techniques such as:

Green Roofs

Permeable Pavement

Rain Gardens

Infiltration Swales

Vegetated Filter Strips

Storm Water Wetlands

Bioretention

Sand Filters

Sources of information on these practices include the U S Environmental Protection Ag

water pollutant loads currently discharging from this area. If this alternative is selected, the

storm water permit compliance strategy will be important and should be documented in the


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p p gy p

7.0 RECOMMENDED WET WEATHER CONTROL PLAN


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7.1 PRIORITY PROJECTS

Integrated Wet Weather Program - Priority Projects and Implementation Strategy

Results of the collection system analysis and integrated wet weather planning process pr

for a recommended solution that is based on maximizing the use of existing conveyance

facilities in combination with selected source controls and strategic placement of stora

magnitude of that work exceeds the near term financial capacity of the City of Lansing (C

phased approach for implementation is required. The phased approach identifies priority 5-year implementation periods. Results from each implementation period will be used t

priority projects for the next 5-year project period. The proposed priority project

implementation period are briefly described below.

1. Basement Backup Protection Program - Source control is proposed as part of the

using a voluntary approach for those areas with recurring basement flooding and hig

flows. This work will involve implementing a basement sewer disconnection program

for targeted areas to protect homeowners, removing footing drain flows, determinin

removal effectiveness, and expected details on how to include basement disconnectio

drain removal work in the full plan. The City is proposing to begin this work in year 1

each year for 5 years, with the last year including an effectiveness evaluation.

2. Siphon 11 Improvements - Wide spread basement flooding in HH North and HH Souresult of Siphon 11 capacity limitations. It would be difficult to keep the 4th barrel

implement an emergency bypass program that reduces basement flooding for this l

current capacity of Siphon 11 is 33 million gallons per day (MGD) and the upstream an

sewer capacities are approximately 44 MGD. The proposed project will include cons

three barrel inverted siphon with new chambers to make it easier to operate and ma

opinion for this project is $4,800,000.

3. Siphon 12 Improvements - Increased capacity improvements for Siphon 12 will be

before separating additional areas (034C and 034D) tributary to Moores Park Trunk S

that existing basement flooding occurring in Combined Sewer Overflow (CSO) A

4. Sunnyside Sewershed - Divert a portion of the Sunnyside area to the Fayette Stree

and construct upstream connection to the Sycamore-Lindbergh Interceptor (SLI


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basement flooding issues when operating the SLI at capacity or slightly surcharged c

cost opinion for this project is $1,300,000.

5. Tecumseh River Pump Station - A new force main will increase the pumping capa

with the upstream gravity sewer capacity. In addition, the proposed route will dis

Wastewater Treatment Plant (WWTP) headworks and reduce surcharging conditions

Interceptor. The force main will likely reduce energy costs, significantly reduce base

and is consistent with the overall Wet Weather Control Plan (WWCP) and meet the 25

design criteria. The cost opinion for this project is $1,500,000.

6. Frances Park Pump Station - A parallel force main will increase the pumping capac

with the upstream gravity sewer capacity. The force main will reduce SSOs at G

consistent with the overall WWCP and other improvements needed to meet the 25

design criteria. The cost opinion for this project is $3,000,000.

7. Storm Water - The City has evaluated storm water pollutant sources as part of

Separate Storm Sewer System (MS4) permit process. One area that would provide

opportunity for improving wet weather water quality is to improve storm water manage

at the Potter Park Zoo which is located along the banks of the Red Cedar River.

8. Regulator 033 - CSO separation work tributary to this regulator will allow closure of

Project Performance Certification (PPC) work will be performed to establish detaabandon this

Documents

Lansing Wet Weather Control Plan