Benefits of Watershed-Based NPDES Permitting - CLU-IN Watershed-based... · Benefits of...

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Office Wastewater Management1

Benefits of Watershed-Based NPDES Permitting

Patrick Bradley, USEPA Water Permits DivisionJenny Molloy, USEPA Water Permits Division

Robert Steidel, City of Richmond, Department of Public UtilitiesFederico Maisch, Greeley & Hansen

Wednesday, July 19 , 2006

This Webcast is sponsored by EPA's Watershed Academy

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Outline

Introduce the concept of watershed-based approaches, including permittingWet WeatherCase Study – Richmond, VALayering paradigms

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What Is WatershedWhat Is Watershed--Based Permitting?Based Permitting?

An approach to NPDES permitting that results in permits:

Designed to attain watershed goals due to the consideration of all sources/stressors in a watershed or basinDeveloped via a watershed planning

framework to communicate with stakeholders and integrate permit development among monitoring, water quality standards, TMDL, nonpoint sources, source water protection and other programs

•

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Expected Benefits & Challenges

BenefitsBetter quality NPDES permitsEmphasis on environmental results due to watershed planningPromotes watershed monitoring plansEncourages efficiencies and targets resources Increased stakeholder involvement

ChallengesExpanded stakeholder involvementIntegrating nonpoint sourcesTransition costs

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Who Initiates a Watershed-Based Permitting Approach?

Can start at any levelPermitting authorityPoint sourcesWatershed organization

Requires support of Permitting Authority and EPA Regional Office

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Step 1: Select a Watershed

Step 2: Identify and Engage Stakeholders

Step 3: Analyze Watershed Data

Step 4: Develop Permit Conditions

Step 5: Issue Watershed-Based NPDES Permit(s)

Step 6: Measure and Report Progress

Basic Steps to WBP

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Sustainable Water Infrastructure

- Our wastewater and drinking water systems are aging

- U.S. population is increasing and shifting- Current treatment and management may not

be sufficient to address emerging issues and potentially stronger requirements

- Investment in R&D has declined- Funding gap: $270 billion for wastewater and

$263 billion for drinking water

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- Seek innovative approaches and new technologies to help ensure that the Nation’s water infrastructure is sustainable

- Accomplish this through collaboration with external stakeholders and conducting research, in the following 4 “pillar” areas:

- Better Management- Water Efficiency- Full Cost Pricing - Watershed-Based Approaches

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Watershed Approach Pillar

Integrate water utility management and watershed planning, allowing stakeholders to take advantage of the full range of tools and approaches to help them make optimal infrastructure decisions and achieve watershed goals

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A Concept for the Integration of Wet Weather Programs

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Key Discussion Areas

Wet weather discharges and what we are doing to control them?The need for wet weather integrationWhat might an integrated wet weather program look like?

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Wet Weather Overview

Municipal wet weather dischargesCombined Sewer Overflows (CSOs)Sanitary Sewer Overflows (SSOs) Stormwater runoffPeak wet weather flows at POTWsUrban nonpoint sources

What is the most effective way to control urban wet weather discharges for the best water

quality outcomes?

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Wet Weather OverviewWet weather discharges:

Contribute similar pollutants (e.g., BOD, suspended solids, pathogens, toxics)Collectively contribute to one of the most serious causes of impairment: discharge volumeOften discharge simultaneously Are variable in terms of event frequency, duration, volume and pollutant loadOften difficult to partition causes of impairment(s) among multiple wet weather sources

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What is the Urban Wet Weather Problem?

EPA’s National Water Quality Inventory 2000 Report identified “municipal point sources” and “urban runoff/storm sewers” as leading sources of impairmentTop 3 pollutants in impaired waters:

Suspended solids PathogensNutrients

All three pollutants present in municipal wet weather sources

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Physical and biological impacts of wet weather discharges can be severe

e.g., altered hydrology habitat impairment

Population growth and new development increasing demands on the urban environment

More difficult to achieve and maintain water quality standards in coming years

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Current regulatory, management and funding approaches address wet weather sources under separate Clean Water Act, and sometimes state, programs

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NPDES Universe

1972 1977 1982 1987 1992 1997 20020

100

200

300

400

500

600

Municipal and Industrial Sources

(100,000)

Stormwater Phase II

(115,000)CAFOs

(15,000)

Stormwater Phase I

(270,000)

Perm

ittee

s (t

hous

ands

)

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Estimated Annual Municipal Point Source Discharges

Source

Treated wastewater 11,425

Urban stormwater 10,068

CSO 850

SSO 10

Total 22,353

Average DischargeVolume (billion gal.)


Report to Congress on the Impacts and Control of CSOs and SSO (EPA 2004)

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Pollutant Concentrations in Municipal Point Source Discharges

Source(Annual Volume)

BOD5(mg/l)

TSS(mg/l)

Fecal Coliform(colonies/100ml)

Treated Wastewater(11,425 BG)

30a 30a <200a

Stormwater(10,068 BG)

0.4-370 0.5-4,800 1-5,230,000

CSO (850 BG)

3.9-696 1-4,420 3-40,000,000

SSOb

(10 BG)6-413 10-348 500,000c

aTypical limit for wastewater receiving secondary treatment/limit for disinfected wastewaterbConcentration in wet weather SSOscMedian concentration (WDNR 2001)

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What are we Currently Doing?

Stormwater Permitting

Regulated Stormwater Discharges:Stormwater Discharge from MS4sStormwater Associated with Industrial ActivityStormwater Discharges from Construction Sites“As Designated” Discharges

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Stormwater Discharges

* This reflects an estimate of the number of new construction starts annually based on data from Phase II Economic Analysis

100,000--100,000Industrial

400,000200,000200,000Construction*

7,0006,0001,000MS4

TotalPhase IIPhase IDischarger

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2000 Census, Urban Areas

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Municipal StormwaterPhase I - individual permit conditions (6mm+)Phase II – 6 minimum measures

Industrial StormwaterStormwater Pollution Prevention Plan for industrial stormwater discharges

Construction StormwaterStormwater Pollution Prevention Plan for construction stormwater discharges; primarily erosion and sedimentation control

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Combined Sewer Overflows

Report to Congress on the Impacts and Control of CSOs and SSO (EPA 2004)

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CSOs are point sources subject to NPDES permit requirements

824 active CSO permits (9,119 discharge points) in 32 states

National CSO Control Policy (1994)– Nine Minimum Controls– Long Term Control Plan

Wet Weather Water Quality Act (2000)Reports to Congress“Shall Conform”


Combined Sewer Overflows

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CSO Control Policy Implementation

CWA Sec 402(q)(1) -- permits and orders “shall conform to” the 1994 CSO Policy

Encouraging the use of EPA’s Guidance: Coordinating CSO Long-Term Planning With Water Quality Standards Reviews as CSO communities, NPDES and water quality standards authorities, and stakeholders coordinate in the development of LTCPs

Providing Regions and NPDES states with guidance and assistance for reviewing and approving LTCPs

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Sanitary Sewer Overflows

National SSS Distribution(15,582 with POTWs; 4,846 satellites)

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Sanitary Sewer Overflows

Not Specifically Addressed under the CWAEPA does not have a national policy or regulationCurrent approach developed ad hoc through implementation of NPDES Permit, Construction Grants, and enforcementSSO Guidance (CMOM, reporting & recordkeeping, satellite systems)

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Report to Congress on CSOs and SSOsKEY MESSAGES

Impacts tend to be more clearly observable at the local watershed level than at the national levelCSOs and SSOs can cause significant environmental and human health impacts at the local watershed level

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Peak Wet Weather Flows at POTWs

National Municipal Policy on Publicly-Owned Treatment Works – focused little attention on management of peak flows“Blending”/”Peak Flows”

Management of peak wet weather flows by routing some peak flow around treatment units, blending the rerouted flow with the flow receiving full treatment; and disinfecting if requiredProposed Blending Policy (99,000+ comments received)New proposed policy for “Peak Flows”

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Nonpoint Source PollutionNo federal regulatory program

Implemented through EPA-approved State programs that include a mix of non-regulatory and regulatory programs as designed by each State

EPA's role focuses on establishing grant requirements that focus State activities on achieving WQ improvement results; providing technical guidance, working with a broad range of partners to promote the widespread demonstration and dissemination of the most effective practices, and supporting outreach and education efforts

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What Have We Learned?

Wet weather programs involve sewer pipes and other infrastructure that share capacity, infiltration, and inflow problemsGreater gap between municipal wastewater infrastructure needs and fundingIncreasingly difficult decisions about how to allocate limited resources

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Current NPDES Framework

Issuing permits for wet weather sources takes time and is resource intensive

Permit-by-Permit ConditionsDifficulty in establishing compliance endpoints

Difficult to assess impacts and program effectivenessMunicipal wet weather discharges are addressed through various regulatory and policy frameworks

Inefficient given commonalities between discharges

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Control of Wet Weather Discharges

Stormwater PermittingCombined Sewer OverflowsSanitary Sewer Overflows

Management of Peak Wet Weather Flows at POTWs

(Nonpoint Sources)

Integrated Wet Weather Programs

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Wet Weather Integration

Relatively few communities have an integrated permit or manage wet weather issues collectivelyEPA working to identify what has slowed progress to date and what could promote further integration

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Wet Weather Integration in Urban Areas

Gathering information via community interviews:

Communities working to integrate their wet weather programs

– Kentucky Sanitation District Number 1Communities with integrated permit requirements

– Clean Water Services (Oregon)Communities that collectively manage urban point source issues but do not have an integrated permit

– Philadelphia Water Department

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Benefits of Wet Weather Integration

Increased flexibility relative to traditional permit requirements that allows permittees to focus on watershed priorities and goals in a systematic and more cohesive manner.Elimination of redundant data collection, data analysis, and reporting requirements.Increased opportunities for efficiency, such as the opportunity for cross training and sharing responsibilities across local program activities. Potential cost savings through the pooling of resources (i.e., GIS applications, monitoring, and modeling).

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Benefits of Wet Weather Integration (cont.)

Promotion of a common and well-balanced understanding of watershed priorities, as well as identification of opportunities for improvement.Encourages a comprehensive view of the watershed that allows evaluation and prioritization of issues at a larger scale, and also allows stakeholders to see water as one resource. Increases potential to achieve greater environmental benefits relative to traditional approach. Allow for meaningful coordination with other programs –TMDL, water quality standards, smart growth initiatives

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Keeping Water Out of Sewer Systems

Wet weather discharges can be hydraulically connected and controlling one source can have impacts elsewhere in the system

CSO separation stormwater impacts

Reducing volume entering the sewer system

A guiding principle for the integration of wet weather permitting programsAddresses the interconnectivity across all wet weather programs (CSO, SSO, stormwater, peak POTW flows)

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Benefits of Keeping Water Out of Sewer Systems

Preservation of sewer system conveyance capacity

Reduction of stress on existing sewer infrastructure

Abatement of combined sewer overflows (CSOs) and sanitary sewer overflows (SSOs)

Reduction in the volume of storm water and associated pollutant loads delivered to water bodiesReduction in the erosion and scouring of small urban streams that accompanies storm water discharges

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Benefits of Keeping Water Out of Sewer Systems (cont)

Lessening of public health, water quality, and environmental impairment attributable to urban runoff and sewer overflowsImproved effluent quality, on average, from publicly owned treatment works (POTWs) due to lower loads during wet weatherBetter management of combined, sanitary, and separate storm sewer systems and permit programsImproved stream baseflow and groundwater recharge

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Often a combination of practices to reduce impervious cover, control inflow/infiltration to sewers, promote water conservation, and enhance bio-infiltration are required

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Keeping Water Out of Sewer Systems - Calculator

Quantify base sewer flow conditionsSanitary sewage (residential, commercial, industrial)Stormwater

Quantify flow reductions associated with the following practices:

Stormwater runoff reductionInflow controlInfiltration controlWater conservation

Calculate potential reductions to sewer systems

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QUESTIONS?

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Watershed Program Case StudiesCity of Richmond

City of Richmond

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Discussion Topics• The City of Richmond and the Middle James River

Watershed• Introduction (Tidal & Non-tidal)• CSO Phases I & II Performance• LTCP Alternatives & WQ Model Results• Phase III Long Term Control Plan• WQS Gap• Chesapeake Bay Urban Non-Point Storm Water

• Watershed Planning – Endpoint Compliance with WQS• EPA Public Health Guidelines• Geometric Mean and/or Single Sample Maximum• WQ Model Results

• E. Coli• Illness Rate

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Discussion Topics (Continued)• How Can We Reach this Endpoint

• Proposed Path Forward• Watershed Approach - i.e. = CSO control - Case Study Richmond, Virginia

• Compare and Contrast – Why the Watershed Approach • Environmental. Outcome • Quality of life • Make sense• Cost Savings for the Public/Rate/Tax Payers

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Watershed Stakeholders• Public• City of Richmond,

Virginia• Adjacent

Jurisdictions– Henrico– Chesterfield– Goochland– Petersburg– Hopewell– Colonial Heights

• DEQ– WQS Compliance– TMDL Process

• EPA• Non-Governmental

Organizations• Business

– Agricultural– Manufacturing

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Middle James River Watershed

Middle James-Willis

Lower James

James River Basin

City of Richmond

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City of Richmond, Virginia & Middle James River Watershed - Service Territory

Goochland

Hanover

Powhatan

Chesterfield

New Kent

Charles City

Henrico

City of Richmond

Prince George

City of Hopewell

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CSO Areas Associated with Parks & Public Access

Southside James River Park CSO Areas

Northside James River Park CSO Areas

Hampton and McCloy Streets Remote Areas

Other CSO Areas

Legend

64 95

64

95

6464 9595

6464

959552

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History• 1950’s Construction of WWTP & Interceptors• 1970’s First CSO Study• 1983 Shockoe Retention Basin Completed• 1985 VPDES Permit Addresses CSO’s• 1988 Comprehensive CSO Study• 1992 Original Consent Order (Amended in 1996 & 1999)• 2002 Completion of Phases I & II• 2002 LTCP • 2005 Phase III Consent Order• 2006 Program Project Plan

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Richmond’s CSO Control PlanAfter Phase II Improvements

Phase II Improvements

CSO Outfall Controlled

CSO Outfall Separation

Wet Weather Treatment (WWT)

Haxall Canal

Manchester Canal

014 013

FEB

021

002

010

020

033

CSO #4&

5

019

017 016 015

CSO #2

CSO #1018

040

011

CSO #3 008009 007

036006

027 023 024026

012

034

005 039

025

Shockoe Retention Basin

(48 HR, 50 MG)

Shockoe Arch Combined

Sewer

Gillies

001

Huguenot Bridge

003 028

035

004

031

City Dock

006A

006B006C

006E

006D

James

RiverCreekLegend

Cre

ek

Shocko

e

/text

WWT30

MGD

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North Side James River CSO ControlsPrior to

PH II CSOControls

After PH II CSO

Controls

PerformanceRemoves CSOs from sensitive areasReduces CSO loads downriverIncreases CSO treatment

James River James River

Fall Line

R.B.

Shoc

koe Solids &

Floatables Removal

Haxall Canal

Byr

d St

7th

St

6th

St

Gam

bles

H

ill

Park

Hyd

ro

James River James River

Fall Line

R.B.

Solids & Floatables Capture

Capture at Shockoe Retention Basin

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Gambles Hill CSO OutfallPrior to CSO Control (1996)

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Gambles Hill (July ‘99)

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58

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Gambles Hill PerformanceDuring Tropical Storm/ Hurricane Dennis (9/6/99)

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South Side James River CSO ControlsPrior to PH IICSO Controls

After PH IICSO Controls Performance

Removes CSOs from sensitiveareas

Reduces CSO loads downriverIncreases CSO treatmentJa

mes

Riv

er

42nd Street

Reedy Creek

Woodland Heights

Canoe Run

To Side Channels

DWF to WWTP Captures

Solids & Floatables

4.7% Total CSO

Fall Line

TurbulentDischarge

Jam

es R

iver

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60

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42nd Street Regulator Performance During Tropical Storm/ Hurricane Dennis (9/6/99)

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Performance

Retention CSO ControlsPrior to PH IICSO Controls

After PH IICSO Controls

Removes CSOs from sensitiveareasReduces CSO loads downriverIncreases CSO treatment

James River

55 Events/yr130 mg/yr

James River

4 Events/yr29 mg/yr

Solids & FloatablesCaptured To

WWTP

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62

62

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McCloy Shaft

Hampton Shaft

63

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Richmond CSO Program Compliance• The City Has Been Operating Under

Successive Orders With the Board Since 1992

• For 15 Years the City Has Met & Exceeded All Its Commitments to DEQ

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• Endorsement from the Falls of the James Scenic River Advisory Committee for City’s CSO Program Special Order (June 14, 1999)

• “Friend of the River Award” from the James River Association (October 3, 1999)

• 1999 National CSO Control Program Excellence AWARD from the USEPA

• Feature article in the 1999 September issue of “Civil Engineering Magazine”

Local and National Recognition Earned by City’s CSO Program

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Local and National Recognition Earned by City’s CSO Program (continued)

• Engineering Excellence Honor Award from the Consulting Engineers Council of Illinois & American Consulting Engineers Council

• Grand Conceptor Award from the Virginia /American Council of Engineering Companies

• Merit Award from the American Society of Landscape Architects

• Featured in FHWA Transportation Enhancement – ISTEA First of a Kind Project

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Background A1Represents City Replaced with Open Field

Manchester Canal

City Dock

James

River

Haxall l Canal

Creek

Cre

ek

Shocko

e

Gillies

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Background A2City Prior to CSO Controls

Huguenot

Bridge

020

033

019

018017 016 015

Manchester Canal

014 013 021

001

002

003 028027023 024026

012

011010

008009 007

036006

034

035

005004

039

025

031

City Dock


Sewer

006A

006B006C

006E

006D

James

River

Haxall l Canal

GilliesCreek

Cre

ek

Shocko

e


CSO Outfall Uncontrolled

WWTP Discharge


Legend

WWT10

MGD

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69

Background BAfter Phase II Improvements

Huguenot

Bridge

020

033

019

018017 016 015

CSO

#4&5

CSO #2

CSO #1

Manchester Canal

014 013 021

002

003028027023 024026

012

011

CSO #3010

008009 007

036006

040

034

035

005004

039

025

031Shockoe Retention

Basin (48 HR, 50 MG)


Sewer

006A

006B006C

006E

006D

James

River

Haxall l Canal

GilliesCreek

Cre

ek

Shocko

e

CSO Conveyance Pipe

CSO Outfall Controlled

CSO Outfall Separated


Legend 024

001

WWT30

MGD

70

70

Alternative CMaximize CSO Wet Weather Flow Treatment

River

Huguenot

Bridge

020

033

019

018017 016 015

CSO

#4&5

CSO #2

CSO #1

Manchester Canal

014 013 021

002

003028027023 024026

012

011

CSO #3010

008009 007

036006

040

034

035

005004

039

025

031

City Dock

Shockoe Retention



Sewer

006A

006B006C

006E

006D

James Haxall l Canal

GilliesCreek

Cre

ek

Shocko

e

001

WWT135

MGDWet Weather Treatment (WWT)


Legend

/text

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Alternative DNorth Side & Peripheral Flow Equalization & Gillies Ck Conveyance

Huguenot

Bridge

020

033

019

018017 016 015

CSO

#4&5

CSO #2

CSO #1

Manchester Canal

014 013 021

002

003028027 023 024026

012

011

CSO #3010

008009 007

036006

040

034

035

005004

039

025

031

City Dock

Shockoe Retention



Sewer

006A

006B006C

006E

006D

James

River

Haxall l Canal

GilliesCreek

Cre

ek

Shocko

e

FEB

FEBFEB

001

WWT135

MGD


Proposed CSO Conveyance Pipe

Proposed CSO Outfall Control

Proposed CSO Outfall Separation

Proposed Disinfection

Proposal Flow Equalization Basin


Legend

DFEB

/text

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Alternative EIncrease CSO WWF Treatment & Shockoe Expansion With Disinfection Plus Lower Gillies Creek Conveyance

Huguenot

Bridge

020

033

019

018017 016 015

CSO

#4&5

CSO #2

CSO #1

Manchester Canal

014 013 021

002

003028027 023 024026

012

011

CSO #3010

008009 007

036006

040

034

035

005004

039

025

031

City Dock

Shockoe Retention Basin/

Disinfection Facility

(48 HR, 65 MG)

Shockoe Arch Combined Sewer

006A

006B006C

006E

006D

James

River

Haxall Canal

GilliesCreek

Cre

ek

Shocko

e

D

D FEB

001

WWT255

MGD

In-line FEB








Legend

DFEB

/text

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Alternative FControl CSOs to 4 Overflows Per Year

Huguenot

Bridge

020

033

019

018017 016 015

CSO

#4&5

CSO #2

CSO #1

Manchester Canal

014 013 021

002

003028027 023 024026

012

011

CSO #3010

008009 007

036006

040

034

035

005004

039

025

031

City Dock



(24 HR, 65 MG)

Shockoe Arch Combined Sewer

006A006B

006C006E

006D

James

River

Haxall l Canal

GilliesCreek

Cre

ek

Shocko

e

FEB

FEBFEB

DD

DFEB

BMP

Best Management Practices

WWTPPrimary

140-295 MGDFull

80 MGD

FEB

001

WWT250

MGD








Legend

DFEB

/text

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Alternative GComplete Citywide Sewer Separation

021028

010

036

040

020

033

019

018017 016 015

CSO

#4&5

CSO #2

CSO #1014 013

002

003 027023 024026

012

011

CSO #3 008009 007

006

034

035

005004

039

025

031

006A

006B006C

006E

006D

Huguenot

Bridge

Manchester Canal

City Dock

James

River

Haxall l Canal

GilliesCreek

Cre

ek

Shocko

e

To WWTP

To Receiving Water

Storm

Sanitary

To WWTP

To Receiving Water

Storm

Sanitary

To WWTP

To Receiving Water

Storm

SanitaryTo WWTP

To Receiving Water

Storm

Sanitary

001

WWTP45

MGD

75

75

Comparative Water Quality & Cost Performance of Alternatives

Perc

ent o

f Jam

es R

iver

Mile

s Mee

ting

Wat

er Q

ualit

y St

anda

rds

FEDCA2 B G

AlternativeBackground

Cap

ital C

ost (

$1,0

00's

)

Note: The

bacteriological water quality

standard is based on the fecal

coliform 30-day geometric mean of 200 MPN per

100 mL

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0

200

400

600

800

1,000

1,200

1,400

1,600

1,800

2,000

A1

76

76

Water Quality Standards CoordinationPercent of James River Miles Meeting Fecal Coliform WQS

B

F

G

A C

DE

0

400

800

1,200

1,600

2,000

2,400

20% 30% 40% 50% 60% 70% 80% 90% 100%Percent of James River Miles

Meeting Water Quality Standards

Cap

ital

Cos

t ($

Mill

ion

s)

Most Cost Effective& End of

CSO Program

Phase IIInvestment

To Date

DEQ ClosingWater Quality

Gap for Background LoadsIncrease

34% to 70%

Increase34% to 92%

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Alternative EIncrease CSO WWF Treatment & Shockoe Expansion With Disinfection Plus Lower Gillies Creek Conveyance








Haxall Canal

Manchester Canal

014 013

FEB

021

002

010

020

033

CSO #4&

5

019

017 016 015

CSO #2

CSO #1018

040

011

CSO #3 008009 007

036006

027 023 024026

012

034

005 039

025



(48 HR, 65 MG)


Sewer

Gillies

001

Huguenot Bridge

003 028

035

004

031

City Dock

006A

006B006C

006E

006D

James

RiverCreekLegend

Cre

ek

Shocko

e

D

D

/text

FEB

D

WWT255

MGD

78

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• 75th Upper Percentile Value (UPV)– 25% of samples greater than 75th UPV– More values greater than UPV, higher probability of exceeding

the geometric mean

Freq

uen

cy o

f O

bser

ved

Indi

cato

r D

ensi

ties

Water Quality Indicator Density

Distribution Around Mean30 Day Geometric Mean

75th Percentile

EPA’s Implementation Guidance for Ambient Water Quality Criteria for BacteriaNovember 2003 Draft Guidance (Continued)

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Richmond CSO Control Program 30 Day Geometric Mean & Associated Risk Level Maximum Month for Critical Reach

PRELIMINARY

EPA’s Recommended Risk Level forFresh Water

Primary ContactRecreation

1.0% of Swimmers

0.8% of Swimmers

E. C

oli M

onth

ly

Geo

met

ric

Mea

n (

cfu

/10

0m

l)

Phases I & IICSO Control

Complete State WQS Based onRisk Level of 8 illness per 1000

0

100

200

300

400

500

600

700

No CSOControl

Alternative E Separation

206

126

EPA Recommends Risk Level Less Than 10 illness per 1000

80

80

Richmond CSO Control ProgramAverage of River Reaches Days Per Year Exceeding E. Coli 75th Upper Percentile Value

PRELIMINARY

0

20

40

60

80

100

120

140

No CSOControl

Phases I & IICSO ControlComplete

Alternative E Separation

Day

s P

er Y

ear

Exce

edin

gE.

Col

i 33

4 c

fu/1

00m

l124.4 Days

81.2 Days72.1 Days 72.2 Days

Separation Five Times More Expensive than Alternative E

62 62 6262

81

81

Shockoe UV Facility PerformanceJames River Reach 13 for August

8.0

8.5

9.0

9.5

10.0

10.5

11.0

11.5

12.0

12.5

13.0

0 2,000 4,000 6,000 8,000 10,000 12,000Number of UV Lamps at Shockoe

Ris

k Le

vel

(#/1

,000

Sw

imm

ers)

126

142

161

182

206

233

263

297

335

380

429

Mon

thly

Geo

met

ric M

ean

(cfu

/100

mL)

Phase II CSO Controls

South Side DisinfectionExpand Shockoe RB

Shockoe Disinfection

EPA Acceptable Risk Level

Virginia Bacteria WQS

Additional 20% Reduction in Watershed Background Pollutant Load

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Bact WQS

DISCHARGECONTRIBUTORS

REGULATORY PROCESSES

→TMDL→Triennial Review

WLA

AREWLA

ACHIEVABLE

STREAMUSES

UAANO

YES

Watershed Approach

CSOStormwater Agricultural

TRADING

• Environmental• Consensus Approach • Quality of life • Makes sense• Cost Savings for the

Public - Rate/Tax Payers

Why the Watershed Approach?

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Questions?

City of Richmond

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Managing wet weather along the continuum from watershed scale to

site scale is critical.

Coupling smart growth and conservation site design paradigms is absolutely necessary to effectively

protect water quality.

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Conservation Site Designs

Using an ecosystem-based approach to manage storm water

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Basic Premise

Maximize infiltration of precipitation where it falls.Prevents contamination of storm water because it doesn’t have a chance to wash over surfaces picking up contaminants.Promotes ground water recharge.Minimizes flooding concerns.Minimizes in-stream scouring because peak flows are not unnecessarily exacerbated or prolonged by increased runoff.Eliminates or minimizes the need for large, expensive storm water collection, conveyance, storage and treatment systems.

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Minimize Runoff

Reduce storm pipes, curbs and gutters

Reduce building footprints

Preserve sensitive soils

Reduce road widths

Minimize grading

Limit lot disturbance

Reduce impervious surfaces

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Conservation

Open Drainage

Rain Gardens

Amended Soils

Rain Barrel

Reduced Imperviousness

Site Features Porous Pavement

Create a Hydrologically Functional Lot 88

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Site to Neighborhood Scale

In addition to promoting more stable hydrologies with site designs, neighborhood designs can also reduce impervious surfaces across a segment of the scale continuum.

ParkingStreet DesignsInfill and Redevelopment

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Development & Runoff

Scenario A: 1 unit/acre

Scenario B:4 units/acre

Scenario C:8 units/acre

Impervious cover = 65%Runoff/acre = 40,000 ft3/yrRunoff/unit = 5,000 ft3/yr

Impervious cover = 20%Runoff/acre = 19,000 ft3/yrRunoff/unit = 19,000ft3/yr

Impervious cover = 38%Runoff/acre = 25,000 ft3/yrRunoff/unit = 6,000 ft3/yr

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Scenario B: 4 units/acreScenario A: 1 unit/acre

Scenario C: 8 units/acre

Accommodating the same number of houses (8) at varying densities

Impervious cover = 20%Total runoff = 150,000 ft3/yrRunoff/house = 19,000 ft3/yr

Impervious cover = 38%Total runoff = 50,000 ft3/yrRunoff/house = 6,000 ft3/yr

Impervious cover = 65%Total runoff = 40,000 ft3/yrRunoff/house = 5,000 ft3/yr 91

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But watershed managers are not dealing with 8 houses...

Accommodating 10,000 units on a 10,000 acre watershed at different densities

10,000 houses on 10,000 acres produce

187 million ft3 /yr stormwater runoff

Site: 20% impervious Watershed: 20%

impervious


62 million ft3 /yr stormwater runoff

Site: 38% impervious Watershed: 9.5%

impervious


49.5 million ft3 /yr stormwater runoff

Site: 65% impervious Watershed: 8.1%

impervious

The lower density scenario creates more run-off and consumes 2/3 more land than the higher density scenario

1 unit/acre 4 units/acre 8 units/acre

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Principles of Smart Growth

Mixed Use, Walkable Neighborhoods, Public Transit – fewer car trips, less pavement: less impervious surfaceCompact Building Designs – smaller footprints: less impervious surfacePreserve open space, critical natural areasDirect development where there is existing infrastructure; maintain existing infrastructure

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Coupling of Conservation Development Paradigms like LID and Smart Growth

There is no inherent conflict between these approaches, and in fact they work well together when fully understoodBalances small and large scale concernsRequires regional planning and coordinationCan be facilitated by good permit language

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QUESTIONS?

Additional resources

Benefits of Watershed-Based NPDES Permitting - CLU-IN Watershed-based... · Benefits of...

Documents

Transcript of Benefits of Watershed-Based NPDES Permitting - CLU-IN Watershed-based... · Benefits of...