Benefits of Watershed-Based NPDES Permitting

Transcription

1 Benefits of Watershed-Based NPDES Permitting Patrick Bradley, USEPA Water Permits Division Jenny Molloy, USEPA Water Permits Division Robert Steidel, City of Richmond, Department of Public Utilities Federico Maisch, Greeley & Hansen Wednesday, July 19, 2006 This Webcast is sponsored by EPA's Watershed Academy 1 1

2 Outline Introduce the concept of watershedbased approaches, including permitting Wet Weather Case Study Richmond, VA Layering paradigms 2 2

3 What Is Watershed-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 basin Developed 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 3 3

4 Expected Benefits & Challenges Benefits Better quality NPDES permits Emphasis on environmental results due to watershed planning Promotes watershed monitoring plans Encourages efficiencies and targets resources Increased stakeholder involvement Challenges Expanded stakeholder involvement Integrating nonpoint sources Transition costs 4 4

5 Who Initiates a Watershed-Based Permitting Approach? Can start at any level Permitting authority Point sources Watershed organization Requires support of Permitting Authority and EPA Regional Office 5 5

6 Basic Steps to WBP 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 6 6

7 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 7 7

8 Sustainable Water Infrastructure - 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 8 8

9 Sustainable Water Infrastructure 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 9 9

10 A Concept for the Integration of Wet Weather Programs 10 10

11 Key Discussion Areas Wet weather discharges and what we are doing to control them? The need for wet weather integration What might an integrated wet weather program look like? 11 11

12 Wet Weather Overview Municipal wet weather discharges Combined Sewer Overflows (CSOs) Sanitary Sewer Overflows (SSOs) Stormwater runoff Peak wet weather flows at POTWs Urban nonpoint sources What is the most effective way to control urban wet weather discharges for the best water quality outcomes? 12 12

13 Wet Weather Overview Wet weather discharges: Contribute similar pollutants (e.g., BOD, suspended solids, pathogens, toxics) Collectively contribute to one of the most serious causes of impairment: discharge volume Often discharge simultaneously Are variable in terms of event frequency, duration, volume and pollutant load Often difficult to partition causes of impairment(s) among multiple wet weather sources 13 13

14 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 impairment Top 3 pollutants in impaired waters: Suspended solids Pathogens Nutrients All three pollutants present in municipal wet weather sources 14 14

15 What is the Urban Wet Weather Problem? 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 15 15

16 What is the Urban Wet Weather Problem? Current regulatory, management and funding approaches address wet weather sources under separate Clean Water Act, and sometimes state, programs 16 16

17 NPDES Universe 600 Stormwater Phase II Permittees (thousands) Municipal and Industrial Sources (100,000) Stormwater Phase I (270,000) (115,000) CAFOs (15,000)

18 What is the Urban Wet Weather Problem? Estimated Annual Municipal Point Source Discharges Average Discharge Source Volume (billion gal.) Treated wastewater 11,425 Urban stormwater 10,068 CSO 850 SSO 10 Total 22,353 Report to Congress on the Impacts and Control of CSOs and SSO (EPA 2004) 18 18

19 Pollutant Concentrations in Municipal Point Source Discharges Source (Annual Volume) Treated Wastewater (11,425 BG) Stormwater (10,068 BG) CSO (850 BG) SSO b (10 BG) BOD 5 (mg/l) TSS (mg/l) Fecal Coliform (colonies/100ml) 30 a 30 a <200 a , ,230, , ,000, ,000 c a Typical limit for wastewater receiving secondary treatment/limit for disinfected wastewater b Concentration in wet weather SSOs c Median concentration (WDNR 2001) 19 19

20 What are we Currently Doing? Stormwater Permitting Regulated Stormwater Discharges: Stormwater Discharge from MS4s Stormwater Associated with Industrial Activity Stormwater Discharges from Construction Sites As Designated Discharges 20 20

21 Stormwater Discharges Discharger Phase I Phase II Total MS4 1,000 6,000 7,000 Construction* 200, , ,000 Industrial 100, ,000 * This reflects an estimate of the number of new construction starts annually based on data from Phase II Economic Analysis 21 21

22 What are we Currently Doing? Stormwater Permitting 2000 Census, Urban Areas 22 22

23 What are we Currently Doing? Stormwater Permitting Municipal Stormwater Phase I - individual permit conditions (6mm+) Phase II 6 minimum measures Industrial Stormwater Stormwater Pollution Prevention Plan for industrial stormwater discharges Construction Stormwater Stormwater Pollution Prevention Plan for construction stormwater discharges; primarily erosion and sedimentation control 23 23

24 What are we Currently Doing? Combined Sewer Overflows Report to Congress on the Impacts and Control of CSOs and SSO (EPA 2004) 24 24

25 What are we Currently Doing? Combined Sewer Overflows 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 25 25

26 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 26 26

27 What are we Currently Doing? Sanitary Sewer Overflows National SSS Distribution (15,582 with POTWs; 4,846 satellites) 27 27

28 What are we Currently Doing? Sanitary Sewer Overflows Not Specifically Addressed under the CWA EPA does not have a national policy or regulation Current approach developed ad hoc through implementation of NPDES Permit, Construction Grants, and enforcement SSO Guidance (CMOM, reporting & recordkeeping, satellite systems) 28 28

29 Report to Congress on CSOs and SSOs KEY MESSAGES Impacts tend to be more clearly observable at the local watershed level than at the national level CSOs and SSOs can cause significant environmental and human health impacts at the local watershed level 29 29

30 What are we Currently Doing? 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 required Proposed Blending Policy (99,000+ comments received) New proposed policy for Peak Flows 30 30

31 What are we Currently Doing? Nonpoint Source Pollution No 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 31 31

32 What Have We Learned? Wet weather programs involve sewer pipes and other infrastructure that share capacity, infiltration, and inflow problems Greater gap between municipal wastewater infrastructure needs and funding Increasingly difficult decisions about how to allocate limited resources 32 32

33 Current NPDES Framework Issuing permits for wet weather sources takes time and is resource intensive Permit-by-Permit Conditions Difficulty in establishing compliance endpoints Difficult to assess impacts and program effectiveness Municipal wet weather discharges are addressed through various regulatory and policy frameworks Inefficient given commonalities between discharges 33 33

34 Control of Wet Weather Discharges Stormwater Permitting Combined Sewer Overflows Sanitary Sewer Overflows Management of Peak Wet Weather Flows at POTWs (Nonpoint Sources) Integrated Wet Weather Programs 34 34

35 Wet Weather Integration Relatively few communities have an integrated permit or manage wet weather issues collectively EPA working to identify what has slowed progress to date and what could promote further integration 35 35

36 Wet Weather Integration in Urban Areas Gathering information via community interviews: Communities working to integrate their wet weather programs Kentucky Sanitation District Number 1 Communities 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 36 36

37 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)

38 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 38 38

39 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 programs Addresses the interconnectivity across all wet weather programs (CSO, SSO, stormwater, peak POTW flows) 39 39

40 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 bodies Reduction in the erosion and scouring of small urban streams that accompanies storm water discharges 40 40

41 Benefits of Keeping Water Out of Sewer Systems (cont) Lessening of public health, water quality, and environmental impairment attributable to urban runoff and sewer overflows Improved effluent quality, on average, from publicly owned treatment works (POTWs) due to lower loads during wet weather Better management of combined, sanitary, and separate storm sewer systems and permit programs Improved stream baseflow and groundwater recharge 41 41

42 Keeping Water Out of Sewer Systems 42 42

43 Keeping Water Out of Sewer Systems Often a combination of practices to reduce impervious cover, control inflow/infiltration to sewers, promote water conservation, and enhance bio-infiltration are required 43 43

44 Keeping Water Out of Sewer Systems - Calculator Quantify base sewer flow conditions Sanitary sewage (residential, commercial, industrial) Stormwater Quantify flow reductions associated with the following practices: Stormwater runoff reduction Inflow control Infiltration control Water conservation Calculate potential reductions to sewer systems 44 44

45 QUESTIONS? 45 45

46 City of Richmond Watershed Program Case Studies City of Richmond 46 46

47 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 47 47

48 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 48 48

49 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 49 49

50 Middle James River Watershed Middle James-Willis City of Richmond Lower James James River Basin 50 50

51 City of Richmond, Virginia & Middle James River Watershed - Service Territory Goochland Powhatan Hanover Chesterfield Henrico City of Richmond Charles City New Kent City of Hopewell Prince George 51 51

52 CSO Areas Associated with Parks & Public Access Legend Southside James River Park CSO Areas Northside James River Park CSO Areas Hampton and McCloy Streets Remote Areas Other CSO Areas

53 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 53 53

54 Richmond s CSO Control Plan After Phase II Improvements Hugueno t Bridge 020 CSO #4& 5 James River Legend /text 018 Phase II Improvements CSO Outfall Controlled CSO #2 CSO Outfall Separation Wet Weather Treatment (WWT) CSO # Haxall Canal CSO #1 Manchester Canal Shockoe Arch Combined Sewer 031 Shockoe Retention Basin 034 (48 HR, 50 MG) 035 City Dock FEB 006C 006B 006A WWT 30 MGD 006E Shockoe Creek 006D Gillies Creek

55 Prior to PH II CSO Controls North Side James River CSO Controls Park Hydro Gambles Hill 6th St 7th St Haxall Canal Byrd St Fall Line Shockoe Solids & Floatables Removal R.B. James River James River After PH II CSO Controls Solids & Floatables Capture Capture at Shockoe Retention Basin R.B. James River James River Performance Fall Line Removes CSOs from sensitive areas Reduces CSO loads downriver Increases CSO treatment 55 55

56 Gambles Hill CSO Outfall Prior to CSO Control (1996)

57 Gambles Hill (July 99)

58 Gambles Hill Performance During Tropical Storm/ Hurricane Dennis (9/6/99)

59 South Side James River CSO Controls 42 nd Street Reedy Creek Woodland Heights Prior to PH II CSO Controls James River 4.7% Total CSO After PH II CSO Controls James River Performance Removes CSOs from sensitive areas Reduces CSO loads downriver Increases CSO treatment Canoe Run To Side Channels DWF to WWTP Captures Solids & Floatables Fall Line Turbulent Discharge 59 59

60 42nd Street Regulator Performance During Tropical Storm/ Hurricane Dennis (9/6/99) 60 60

61 Retention CSO Controls Prior to PH II CSO Controls After PH II CSO Controls Performance Solids & Floatables Captured To WWTP Removes CSOs from sensitive areas Reduces CSO loads downriver James River James River Increases CSO treatment 55 Events/yr 130 mg/yr 4 Events/yr 29 mg/yr 61 61

62 62 62

63 Hampton Shaft McCloy Shaft 63 63

64 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 64 64

65 Local and National Recognition Earned by City s CSO Program 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 65 65

66 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 66 66

67 Background A1 Represents City Replaced with Open Field Creek Shockoe James River Haxall l Canal Manchester Canal City Dock Gillies Creek 67 67

68 Background A2 City Prior to CSO Controls Huguen ot Bridge 020 James Legend Shockoe Arch Combined CSO Outfall Uncontrolled WWTP Discharge 019 River Haxall l Canal Manchester Canal E 006C 006B 006A 006D 034 Shockoe WWT 10 MGD Creek Shockoe Arch Combined Sewer 035 City Dock Gillies Creek Wet Weather Treatment (WWT)

69 Background B After Phase II Improvements Huguen ot Bridge 020 CS O #4& 5 James 033 CSO # E 006C 006B 006A 006D 019 Haxall l MG) 025 Canal River CSO #1 004 Gillies Legend 021 Manchester CSO # CSO Conveyance Pipe Canal WWT 002 CSO Outfall Controlled 30 MGD 012 CSO Outfall Separated Wet Weather Treatment (WWT) Shockoe Creek Shockoe Arch Combined Sewer Shockoe Retention Basin (48 HR, 031 Creek 69 69

70 Alternative C Maximize CSO Wet Weather Flow Treatment Huguen ot Bridge 020 Legend CS O #4& 5 James Wet Weather Treatment (WWT) /textphase II Improvements River CSO #2 CSO # Haxall l Canal CSO #1 Manchester Canal E 006C 006B 006A 006D 034 Shockoe WWT 135 MGD Shockoe Arch Combined Sewer 031 Shockoe Retention Basin (48 HR, 50 MG) 035 City Dock Gillies Creek 002 Creek

71 Alternative D North Side & Peripheral Flow Equalization & Gillies Ck Conveyance Huguen ot Bridge 020 CS O #4& 5 James River Legend /text 018 Phase II Improvements Proposed CSO Conveyance Pipe CSO #2 Proposed CSO Outfall Control Proposed CSO Outfall Separation D Proposed Disinfection FEB Proposal Flow Equalization Basin Wet Weather Treatment (WWT) Shockoe Arch Combined Sewer 031 CSO #3 008 Shockoe 010 FEB Retention 034 Basin (48 HR, Haxall l MG) 025 Canal 006 City Dock CSO #1 004 Gillies Manchester Canal Creek 006E 006C 006B 006A 006D WWT 135 MGD Shockoe 001 FEB 002 Creek FEB

72 Alternative E Increase CSO WWF Treatment & Shockoe Expansion With Disinfection Plus Lower Gillies Creek Conveyance Huguen ot Bridge 020 CS O #4& 5 James River Legend /text 018 Phase II Improvements Proposed CSO Conveyance Pipe CSO #2 Proposed CSO Outfall Control Proposed CSO Outfall Separation D Proposed Disinfection FEB Proposal Flow Equalization Basin Wet Weather Treatment (WWT) Shockoe Arch Combined Sewer Inline Shockoe Retention CSO #3 008 Basin/ 031FEB Disinfection Facility Haxall Canal (48 HR, 65 MG) City Dock 040 D CSO # D Gillies Manchester Canal Creek 006E 006C 006B 006A 006D FE B Shockoe WWT 255 MGD Creek

73 Alternative F Control CSOs to 4 Overflows Per Year Huguen ot Bridge 020 CS O #4& 5 James BMP River Legend /text 018 Phase II Improvements Proposed CSO Conveyance Pipe CSO #2 Proposed CSO Outfall Control Proposed CSO Outfall Separation D Proposed Disinfection FEB Proposal Flow Equalization Basin Wet Weather Treatment (WWT) Best Management Practices 006E 006C 006B 006A Shockoe 006D Shockoe Arch Combined Sewer Shockoe Retention Basin/ 031 CSO # Disinfection FEB Facility 034 (24 HR, 65 MG) Haxall l Canal 006 City Dock D CSO #1 004 D Gillies D Manchester FEB Canal WWTP Primary FE B WWT 250 MGD MGD Full 80 MGD 001 FEB Creek 002 Creek FEB

74 Alternative G Complete Citywide Sewer Separation Huguen ot Bridge 020 CS O #4& 5 James To WWTP 033 To Receiving Water Sanitary 018 Sanitary 019 River Storm CSO #2 To WWTP To Receiving Water Storm Sanitary Storm To WWTP To Receiving Water 006C 006B 006A 006E Shockoe 006D CSO # To WWTP To Receiving Haxall l Water 025 Canal City Dock CSO #1 004 Gillies Manchester 026 Canal WWTP 45 MGD 001 Creek 002 Sanitary Storm Creek

75 Comparative Water Quality & Cost Performance of Alternatives Note: The bacteriological water quality standard is based on the fecal coliform 30-day geometric mean of 200 MPN per 100 ml Percent of James River Miles Meeting Water Quality Standards 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 2,000 1,800 1,600 1,400 1,200 1, Capital Cost ($1,000's) 0% A1 0 A2 B C D E F G Background Alternative 75 75

76 2,400 Water Quality Standards Coordination Percent of James River Miles Meeting Fecal Coliform WQS Capital Cost ($ Millions) 2,000 1,600 1, A Phase II Investment To Date Increase 34% to 92% Increase 34% to 70% 20% 30% 40% 50% 60% 70% 80% 90% 100% Percent of James River Miles Meeting Water Quality Standards B C D G E F DEQ Closing Water Quality Gap for Background Loads Most Cost Effective & End of CSO Program 76 76

77 Alternative E Increase CSO WWF Treatment & Shockoe Expansion With Disinfection Plus Lower Gillies Creek Conveyance Hugueno t Bridge 020 CSO #4& 5 James River Legend /text 018 Phase II Improvements Proposed CSO Conveyance Pipe CSO #2 Proposed CSO Outfall Control Proposed CSO Outfall Separation D Proposed Disinfection FEB Proposal Flow Equalization Basin Wet Weather Treatment (WWT) CSO # Haxall Canal CSO #1 Manchester Canal D FE B A 006E 006C 006B Shockoe Arch Combined Shockoe Sewer Retention Basin/ Disinfection 034 Facility (48 035HR, City 65 MG) Dock WWT 255 MGD Shockoe Gillies D Creek 006D Creek

78 EPA s Implementation Guidance for Ambient Water Quality Criteria for Bacteria November 2003 Draft Guidance (Continued) 75 th Upper Percentile Value (UPV) 25% of samples greater than 75 th UPV More values greater than UPV, higher probability of exceeding the geometric mean Frequency of Observed Indicator Densities Distribution Around Mean 30 Day Geometric Mean 75 th Percentile Water Quality Indicator Density 78 78

79 E. Coli Monthly Geometric Mean (cfu/100ml) Richmond CSO Control Program 30 Day Geometric Mean & Associated Risk Level Maximum Month for Critical Reach EPA Recommends Risk Level Less Than 10 illness per 1000 EPA s Recommended Risk Level for Fresh Water Primary Contact Recreation 1.0% of Swimmers 0.8% of Swimmers 0 No CSO Control PRELIMINARY Phases I & II CSO Control Complete Alternative E Separation State WQS Based on Risk Level of 8 illness per

80 Richmond CSO Control Program Average of River Reaches Days Per Year Exceeding E. Coli 75th Upper Percentile Value Days Per Year Exceeding E. Coli 334 cfu/100ml Days 62 Separation Five Times More Expensive than Alternative E 81.2 Days 72.1 Days 72.2 Days No CSO Control PRELIMINARY Phases I & II CSO Control Complete Alternative E Separation 80 80

81 Shockoe UV Facility Performance James River Reach 13 for August Risk Level (#/1,000 Swimmers) Shockoe Disinfection Phase II CSO Controls South Side Disinfection Expand Shockoe RB Additional 20% Reduction in Watershed Background Pollutant Load EPA Acceptable Risk Level Virginia Bacteria WQS 0 2,000 4,000 6,000 8,000 10,000 12,000 Number of UV Lamps at Shockoe Monthly Geometric Mean (cfu/100ml) 81 81

82 Why the Watershed Approach? Watershed Approach Bact WQS TRADING CSO Stormwater Agricultural DISCHARGE CONTRIBUTORS Environmental REGULATORY PROCESSES TMDL Triennial Review STREAM USES Consensus Approach Quality of life WLA Makes sense Cost Savings for the Public - Rate/Tax Payers ARE WLA ACHIEVABLE NO UAA YES 82 82

83 City of Richmond Questions? 83 83

84 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

85 Conservation Site Designs Using an ecosystem-based approach to manage storm water 85 85

86 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

87 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 87 87

88 Site Features Reduced Imperviousness Conservation Porous Pavement Rain Gardens Amended Soils Open Drainage Rain Barrel 88 Create a Hydrologically Functional Lot 88 88

89 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. Parking Street Designs Infill and Redevelopment 89 89

90 Development & Runoff Scenario A: 1 unit/acre Scenario B: 4 units/acre Scenario C: 8 units/acre Impervious cover = 20% Runoff/acre = 19,000 ft3/yr Runoff/unit = 19,000 ft3/yr Impervious cover = 38% Runoff/acre = 25,000 ft3/yr Runoff/unit = 6,000 ft3/yr Impervious cover = 65% Runoff/acre = 40,000 ft3/yr Runoff/unit = 5,000 ft3/yr 90 90

91 Accommodating the same number of houses (8) at varying densities Scenario A: 1 unit/acre Scenario B: 4 units/acre X X X Impervious cover = 38% Total runoff = 50,000 ft3/yr Runoff/house = 6,000 ft3/yr Scenario C: 8 units/acre X X X Impervious cover = 20% Total runoff = 150,000 ft3/yr Runoff/house = 19,000 ft3/yr X X X Impervious cover = 65% Total runoff = 40,000 ft3/yr Runoff/house = 5,000 ft3/yr 91 91

92 But watershed managers are not dealing with 8 houses... Accommodating 10,000 units on a 10,000 acre watershed at different densities 1 unit/acre 4 units/acre 8 units/acre 10,000 houses on 10,000 acres produce 187 million ft3 /yr stormwater runoff Site: 20% impervious Watershed: 20% impervious 10,000 houses on 2,500 acres produce 62 million ft3 /yr stormwater runoff Site: 38% impervious Watershed: 9.5% impervious 10,000 houses on 1,250 acres produce 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 92 92

93 Principles of Smart Growth Mixed Use, Walkable Neighborhoods, Public Transit fewer car trips, less pavement: less impervious surface Compact Building Designs smaller footprints: less impervious surface Preserve open space, critical natural areas Direct development where there is existing infrastructure; maintain existing infrastructure 93 93

94 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 understood Balances small and large scale concerns Requires regional planning and coordination Can be facilitated by good permit language 94 94

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96 QUESTIONS? Additional resources 96 96