City of Indianapolis Combined Sewer Overflow (CSO) Program Goes Green 15Sep09

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1 City of Indianapolis Combined Sewer Overflow (CSO) Program Goes Green 15Sep09 APWA 2009 International Congress and Exposition The City of Indianapolis CSO Program Goes Green - Objectives Beware of the Magic Green Infrastructure Introduction to the City of Indianapolis Green Shift in Policy and Practice Background of Green CSO Abatement w/ Costs Discussion on City s Efforts Now and Next Courtesy UNEP Brian Neilson 1

2 Green Infrastructure Definition and Inter-relationships Low Impact Development (LID)- A stormwater management approach that is modeled after nature: manage rainfall at the source using uniformly distributed decentralized site-scaled controls. The goal is to mimic a site's predevelopment hydrology by using techniques that infiltrate, filter, store, evaporate, and detain runoff at its source. Sustainable Site Design -Sustainable development is defined as balancing the fulfillment of human needs with the protection of the natural environment so that these needs can be met not only in the present, but in the indefinite future. Green Stormwater Infrastructure - a stormwater management approach that captures raindrops where they fall, Green Infrastructure utilizes the absorbing and filtering abilities of plants, trees and soil to protect water quality, reduce runoff rates (time of concentration & velocity), reduce runoff volumes, and recharge groundwater supplies. Green Infrastructure is The Foundation of Low Impact Development Low Impact Development is Sustainable Design LID works whether replacing conventional design or in conjunction with it. Mayor s Vision We are committed to making Indianapolis one of the most sustainable cities in the Midwest. It is my sincere belief that environmental sustainability is a key strategy to make sure that Indianapolis continues to be competitive in a changing world, and that our community remains vibrant and healthy for our children and grandchildren. Mayor Greg Ballard While we are headed in the right direction, my vision is for the City to work in close partnership with the community to move forward more aggressively with strategic, sustained action to make Indianapolis one of the most sustainable cities in the Midwest. Brian Neilson 2

3 City s Global Direction CSO Plays only a Part Saving Taxpayer Dollars TRANSPORTION ALTERNATIVES RAIN GARDENS GREEN ALLEYS Building the Local Economy Lower Carbon Footprint PROCUREMENT SUSTAINABLE FUTURE GREEN FLEET Improve Air Quality RECYCLING ENERGY EFFICIENCY Attract Residents and Industries BIKE PATHS CONSENT DECREE Improve Community Quality of Life City s Goals sustainindy.org Reduce storm water going to combined sewer overflows (CSOs) g g ( ) Improve water quality for people and wildlife Improve air quality, energy conservation and efficiency Increase public education and understanding of impacts City beautification and increased quality of life (live, work, play) Foster a low impact ethic; create a more sustainable city Brian Neilson 3

4 City s Progress 2007 Creation of the Indianapolis Green Print 2008 Mayor Ballard Elevates it to a Green Commission Mayor Ballard Creates the Office of Sustainability 2009 Hold onto your hats folks, the Office of Sustainability produces extraordinary results in 1 - year City s Implementation Program and Policy Building Past Green Supplemental Document into Storm Water Design Manual Public information and education sessions Fact sheet and site design examples Ordinance/incentive/policy review (Green Committee-Commission) Internal staff training Sustainable Infrastructure Initiative Current Green Infrastructure (GI) Master Plan Public Projects that promote Green Roofs, Green Alleys, and Bioretention (Rain Gardens) Neighborhood Revitalization St. Clair LEED ND Future Elevate GI Master Plan from a concept to a block-by-block evaluation in CSO Service area. Public / Private Partnerships Ordinance / Policy Guidelines, Updates and Implementation Brian Neilson 4

5 Fact Sheet and Site Design Examples Public & Staff Education Real In-the-Ground Examples around the City providing CSO Abatement. Use of The Nature Conservancy for both Ultra Urban Re-development and CSO Abatement Keep Indianapolis Beautiful parking Indianapolis Glick Cultural Trail Bioretention Green Infrastructure Master Plan Concept to Implementation Overall CSO GIS Analyses Citywide GI BMP Survey CSO Sub-watersheds GIS Analysis Neighborhood Pilot Site Selection Integrate Cost Benefit and Pilot Project Design Into CSO Abatement Tunnel Facility Plans Study Pilot Project Effectiveness Full Scale Implementation Brian Neilson 5

6 CSO Long Term Control Plan 20 year plan to reduce raw sewage overflows Largest investment in clean water infrastructure in city history Ensures compliance with consent decree and Clean Water Act CSO LTCP estimated to be $1.7 billion by 2025 (2004 dollars) Overall Wet Weather Program Estimated to be $3.5 Billion What Does It Look Like? Low Density Residential Brian Neilson 6

7 What Does It Look Like? Medium Density Residential What Does It Look Like? High Density Residential Brian Neilson 7

8 What Does It Look Like? Neighborhood Retail What does it look like - Permeable Pavement Invisible Structures Plastic Reinforcing Grid Permeable Interlocking Concrete Pavers (PICP) Concrete Grid Pavers (CGP) Pervious Asphalt Pervious Concrete The porosity allows pavement infiltration rate up to 400 in/hr. (Pilat, 2002) ervious Concrete w/ Hose Photo by Greg ckinnon from Puget Sound Online Pe M Soil Filled for Grass Growth Gravel Filled The fear of catastrophic failure after proper construction is fictional. for any anticipated rain event. (Hunt, 2007) Brian Neilson 8

9 Underground Detention - Conventional City of Indianapolis, IN Tunnel storage Considerations Costs that can approach $4.00 (+) per gallon They have to be pumped up to 250 feet up! That means very large pumping stations Maintenance can be expensive (they have to be cleaned) Every gallon from a tunnel or underground storage facility for CSO is sent to a wastewater treatment plant to be treated. Check your WWTP energy costs/needs. These costs will be with your City forever! City of Chicago TARP Tunnel storage City of Indianapolis, IN White River IUPUI storage Combined Sewer Overflow LTCP - Costs Terre Haute, IN The selected conventional alternative was evaluated on a cost established with a range (roughly) between $9.50 to $12.75 per gallon cost of underground storage. Chicago, IL Deep Tunnels (TARP) downspout disconnection could achieve peak flow reductions in the 1,370-acre area by 30% for a six-month or one-year storm 3-inch and 6-inch deep rain gardens installed at each home could reduce total runoff by approximately 4% and 7%, respectively Before Removed a 630 foot long, 16 foot wide asphalt alley and replaced it with a permeable paving system. The Green alley infiltrates and retains the volume of a 3-inch, one-hour rain event. Green Roof show 50% reduction in stormwater runoff Green Roof Retrofit Costs (City of Chicago) around $10/sq. ft. After Brian Neilson 9

10 BMP Performance Milwaukee, WI and Portland, OR Milwaukee, WI Portland, OR Photo courtesy of Portland Bureau of Environmental Services Portland, Oregon Portland s dual approach to managing CSOs The Big Pipe CSO tunnel and Green Infrastructure: Green Roofs, Rain Gardens, vegetated swales and Downspout disconnection, rain barrels, cisterns (stormwater sumps) After 10 years, The Portland Bureau of Environmental Services has found that Green Infrastructure techniques: -Reduce peak flows by at least 80-85% SW 12 th Ave Stormwater Planter -Retain at least 60% of the storm volume of a CSO design storm - Disconnection of over 49,000 downspouts, paying $53 per downspout for a total cost of about $2.5 million, has reduced over 1.2 billion gallons of runoff from reaching sewers, reducing overflows by 10 percent. Disconnection Program Value = $0.002 per gallon Data Courtesy of the Center For Neighborhood Technology Water line Porous paver Tree Well Brian Neilson 10

11 New York, New York Cost Comparison of CSO Controls CSO Reduction per $1000 Construction Costs Traditional CSO Controls Source Controls Gall ons CSO Reduction Per Year Courtesy of Hudson River Riverkeeper Sustainable Raindrops Green Roof Incentive is a proposed cost sharing for the incremental difference of a traditional roof to a green roof. Louisville and Jefferson County MSD MSD is one of the first CSO communities in the U.S. to integrate fully a comprehensive green infrastructure initiative into the CSO LTCP planning process. (well then again there is Columbus, Ohio) Pilot Program intended for immediate implementation; Green Alleys potential project sites to remove 3 MG from CSS Dry Wells potential to remove 1.5 MG Green Parking Lots potential to remove over 4.5 MG Rain Gardens (yeah!) potential to remove 2.6 MG Green Street potential to remove 0.5 MG $0.12 cost per gallon (pilot level) Brian Neilson 11

12 Louisville and Jefferson County MSD Table summarizes MSD s proposed regional Green Infrastructure program initiative and compares estimated costs over a 15-year program and benefits form a stormwater reduction perspective. By partnering and offering incentives and partial subsidies to encourage GI investments. MSD expects to leverage its spending to more than double GI community wide. $0.09 Downtown Revitalization (and CSO Control!) Indianapolis, IN Indianapolis Cultural Trail - A world-class urban bike and pedestrian path that connects neighborhoods, cultural districts and entertainment amenities, and serves as the downtown hub for the central Indiana greenway trail system. Phase 1 Alabama Street (completed) has ten (10) bioretention areas as part of its stormwater collection Cultural Trail: East Corridor Courtesy of Rundell & Ernstberger Associates Brian Neilson 12

13 Downtown Revitalization (and CSO Control!) Indianapolis, IN Cultural Trail Courtesy of Rundell Ernstberger Associates, LLC Downtown Revitalization (and CSO Control!) Indianapolis, IN Analyzing 5 years of historical rain records, the bioretention rain gardens designed and constructed in the Phase 1 - Alabama Street (1/2 street only) provided the following results for potential CSO abatement: 100% of all rain events about an inch or less are stored, infiltrated and removed from the Combined Sewer System On average, the bioretention areas for all rain events will remove 240,000 gallons of rain runoff annually. This equates to keeping 91% of all annual rainfall runoff from the combined sewer system. Of note: 1. The Cultural Trail is privately funded, almost all CSO benefits were not paid for by rate payers. Courtesy of Rundell Ernstberger Associates, LLC Brian Neilson 13

14 City Pilot Project -Fall Creek and College Avenue Bioretention Construction to be completed by end of 2009 Estimates reducing the overall cost of CSO LTCP by up to 5% City Pilot Project Residential High Density St. Clair Place Revitalization of Existing Neighborhood Office of Sustainability and Department of Metropolitan Development CSO Service Area Green Alleys Bioretention Open Space / Community Parks All Other Benefits Brian Neilson 14

15 TNC Headquarters Has Been Used Since Its Conception for Education Comparison of Conventional To Low Impact Development (LID) Ultra Urban Site Re-development Nature Conservancy Headquarters Existing Condition 2% Permeable Surface No Infiltration 100% Discharge Stormwater Into the Combined Sewer Area 614 E. Ohio Street Brian Neilson 15

16 TNC Headquarters Conventional Site Design & Drainage Per Code: Single Story office building Little to No landscaping required Underground detention with continuous discharge to the CSO system Conventional Site Example E. Ohio Street N. East Street Although perhaps more landscaping than required by code, this 5/3 Banking Site just west of the existing site is similar in nature to the Conventional Site used in the comparison exercise Brian Neilson 16

17 LID Typical Site Landscape Design Had to go with a 2- story building to get equal useable space All Permeable Pavement Bioretention Full Green Roof In comparison: the exercise s Example LID site has more permeable pavement and bioretention then the actual Nature Conservancy site. (assumed Type B soils) The actual site intends to utilize underground infiltration gallery for stormwater management due to high permeability of sandy, gravel subsurface soils. Stormwater and Cost Comparison The Real project has opportunity for 0.0 discharge into the CSO system. 100% removal! Currently at no cost to the City!? These estimates are when the LID site is extrapolated to the downtown Indianapolis milesquare area Information Courtesy of AMEC, Elements Engineering, & EMH&T Brian Neilson 17

18 6" Evans, Mechwart, Hambleton & Tilton, Inc. Nature Conservancy Headquarters - Post Developed 1 7 S EE GRA DING PLAN H:V 11 6 DAYLIGHT UNDERDRAIN 1 5 SEE GRADING PLAN H:V % " SSD 2.0' " 1.0% 12" 2.5' 3.0' " dia. PERFORATED HDPE PIPE 12" 12" LANDSCAPE OR GRASS FILTER STRIP 2 STRAIGHT CONCRETE CURB 3 IMPERVIOUS CONCRETE OR ASPHALT SURFACE 4 PERVIOUS PAVEMENT SECTION - SEE SITE PLAN 5 CONCRETE LEDGER BAND - SEE SITE PLAN INCH MAX. PONDING WATER QUALITY STORAGE VOLUME 7 TOPSOIIL INCHES OF COMMERCIALLY AVAILABLE FINE SHREDDED HARDWOOD MULCH OR SHREDDED HARDWOOD CHIPS FEET DEPTH PLANTING SOIL BED SEE THE ENGINEERED SOIL MIX FOR INFILTRATION TREATMENT FOR DETAILS 10 6-INCH PERFORATED DUAL WALL PVC UNDERDRAIN COLLECTION SYSTEM. MINIMUM GRADE OF 0.50 % MUST BE MAINTAINED " dia. OVERFLOW STRUCTURE TO UNDERGROUND 48" PIPE. 12 GEOTEXTILE SEPARATION FABRIC 13 OPEN-GRADED AGGREGATE WITH 40 % VOIDS. #73 COARSE AGGREGATE PLACED IN LOOSE 8" LIFTS AND COMPACTED TO 90 % MODIFIED PROCTOR DENSITY. 14 COMPACTED AGGREGATE BASE (SEE PAVEMENT SECTION) 15 COMPACTED SUBGRADE SLOPED TOWARD BIORETENTION SYSTEM 16 PERMEABLE IN-SITU GRANULAR SOILS 6" WQ-12B INDIANA COBBLE CHECK DAM, BEYOND SEE SITE LAYOUT PLAN FOR LOCATIONS; SEE SITE GRADING PLANS FOR RIDGE ELEVATION; REFER TO SITE UTILITY PLAN & DETAILS FOR DRAINAGE REQUIREMENTS INDIANA GRANITE BOULDER(S) SEE PLANS FOR GENERAL LOCATIONS & QUANTITIES; SEE SITE GENERAL NOTES 10 & 11. SEE GRADING PLAN H:V BIORETENTION ADJACENT PERVIOUS PAVEMENT 5 - FULL INFILTRATION 11 1 DAYLIGHT SEE GRADING PLAN 6 UNDERDRAIN H:V SCALE:NONE NATIVE BIO-RETENTION PLANT MATERIAL SEE LANDSCAPE PLANS LIMITS OF RETENTION CAPACITY; SEE UTILITY PLANS & DETAILS INDIANA COBBLES SEE PLANS FOR GENERAL LOCATIONS & QUANTITIES; SEE SITE GENERAL NOTES 10 & 11. NATIVE BIO-RETEN SEE LANDSCAPE P " SSD 2.0' " 1 PERMEABLE P SUBSURFACE SEE SITE LAYO 2.5' 3.0' SWALE FLOWLINE " 12 SWALE GRADE BEYOND SEE GRADING PLANS TOPSOIL SEE DETAIL 1, L 103 & SPECS COMPACTED SUBGRADE SEE SPECS ENGINEERED SOIL MIX SEE UTILITY PLANS & DETAILS UNDERGROUND EXFILTRATION SYSTEM SEE UTILITY PLANS & DETAILS 48" dia. PERFORATED HDPE PIPE 12" 12" " SWALE Public Private Partnerships Influence of TNC Public Private Partnership with Large Pharmaceutical Corporation with over 30 acres of parking lot. Brian Neilson 18

19 City Pilot Project Christian Park Open Space Rain Gardens City Pilot Project Christian Park Open Space Rain Gardens Brian Neilson 19

20 Taking it from 50,000 foot Planning Level to the Street Green Infrastructure Compliance Modeling -EPA SWMM 5.0 -WINSLAMM -RECARGA EPA SWMM - Used by USEPA for Compliance Monitoring Not Yet Equipped to Easily Handle Green Infrastructure Primary platform for CSO modeling Proprietary versions XP-SWMM PC-SWMM Hydraulics Package Dynamically models flow in pipes Very technical model Hydrology Package Uses common TR-55, Green-Ampt, etc, methods for runoff Brian Neilson 20

21 WINSLAMM Green Infrastructure & SWMM Compatible SWMM Compatible Hydrology package, which will model: Continuous rainfall or single events Bioretention Pervious pavement Disconnected impervious areas Vegetated swales Wet Basins Compatibility allows WinSLAMM output to be directly converted to SWMM input One of the most important aspects of WinSLAMM is its ability to consider many stormwater controls (affecting source areas, drainage systems, and outfalls) together, for a long series of rains. Another is its ability to accurately describe a drainage area in sufficient detail for water quality investigations in accurately predicting discharge results. (Dr. Robert Pitt, Green Infrastructure Performance Modeling with WINSLAMM, May 2009) WINSLAMM Green Infrastructure & SWMM Compatible Ease of Data Entry and Evaluation Brian Neilson 21

22 RECARGA Infiltrative Green Infrastructure Developed by the University of Wisconsin NRCS Runoff Curve Number Method Continuous or Single Event Rainfall Very detailed water balance calculations So How Do These Tools Help? 100% Ponding Depth = 10 90% d % Annual Runoff Volume Treated 80% 70% WINSLAMM RECARGA Table 1 Table 1 -Bioretention Sizing Study Runoff Treatment Modeling Results (WinSLAMM) Bioretention Surface Area as a Percentage of Impervious Area Tributary to Basin 2% 78.8% 3% 88.4% % Annual Runoff Treated 4% 93.4% 5% 97.2% 6% 99.0% 7% 99.7% 60% 0% 1% 2% 3% 4% 5% 6% 7% 8% Bioretention Surface Area as Percentage of Impervious Area Tributary to Basin Brian Neilson 22

23 Urban Green Infrastructure Runoff Redirection Cost Analysis Table 2 - Urban Green Infrastructure Runoff Redirection Cost Analysis Runoff Redirection Options Break Even Period (years) Roadway (only) Runoff Redirection 46 Roadway and Roof Runoff Redirection 12 Roadway and Roof Runoff Redirection with Tunnel Storage Volume Reduction 7 Assumptions: Costs Bioretention concrete, retaining wall support (Ohio) = $154.51/sq.ft. Bioretention Maintenance (Ohio/Indiana) = $ 1.90/sq.ft. Tunnel Storage Cost (Ohio/Indiana + other available data) = $ 3.80/gal. Wastewater treatment costs (Indpls.) = $ 0.01/gal. Tunnel Storage Diversion Assume 20% of total annual volume diverted for peak flow reduction CSO Long Term Control Plan 50,000 Feet From the GI Master Plan Green alleys Green parking lot Green street rain gardens Green roofs Green space Other Data: Residential rain gardens Rain barrels Sewer Separation Along Green Corridors From the CSO Tunnel Projects Permeable Pavement Streets (this is big) Brian Neilson 23

24 Street Level Evaluation (Columbus, OH RiverSouth) Street Level Evaluation (Columbus, OH RiverSouth) Brian Neilson 24

25 BMP Selection & Evaluation (Columbus, OH RiverSouth) BMP Selection & Evaluation (Columbus, OH RiverSouth) Brian Neilson 25

26 BMP Selection & Evaluation (Columbus, OH RiverSouth) BMP Selection & Evaluation (Columbus, OH RiverSouth) Brian Neilson 26

27 BMP Selection & Evaluation (Columbus, OH RiverSouth) It s an Engineered Treatment Facility that Requires Due Diligence for Type and Location Selection BMP Street Level Construction (Columbus, OH RiverSouth) Before Brian Neilson 27

28 BMP Street Level Construction (Columbus, OH RiverSouth) West Columbus Street Porous Concrete Brian Neilson 28

29 Cost Effectiveness of LID for CSO Control F. Montalto et al, Rapid Assessment of the Cost Effectiveness of Low Impact Development for CSO Control, Landscape and Urban Planning 82, 2007, pp Operation & Maintenance A Must! Brian Neilson 29

30 Green Infrastructure and CSO Abatement BMP Classification System BMP Volume Peak Discharge Water Quality Downspout Disconnection Filter Strips Infiltration Practices Pocket Wetlands Porous Pavement Rain Barrels/Cisterns* Rain Gardens * A single cistern typically provides greater volume reduction than a single rain barrel. Key: High effectiveness Medium effectiveness Low effectiveness And finally. It works! BMP Classification courtesy of Water Environment Research Foundation (WERF) Project 03-SW-3 Decentralized Stormwater Controls for Urban Retrofit and CSO Reduction Remember the Due Diligence for your Designed Facility BIORETENTION / RAIN GARDEN BMP SECTION 1 SURFACE - TSS, OILS & GREASE 2 SUB-SURFACE (0-12") - PATHOGENS, PHOSPHORUS, METALS 3 SUB-SURFACE (30"-36") - NITROGEN, TEMPERATURE Brian Neilson 30

31 Some Interesting Questions (For Me Anyway) So who is telling the Cities and Towns that once they separate their CSOs that their MS4 boundaries increase? Is it more cost effective to meet Water Quality Standards through the MS4 or the CSO programs? summarizing states current practices for developing TMDL s and for implementing TMDL s through stormwater permitting. Total Maximum Daily Loads and National Pollutant Discharge Elimination System Stormwater Permits for Impaired Waterbodies: A Summary of State Practices, USEPA Region V, September 15, 2007 Contributing Stakeholders Thanks to the following organizations and consultants who have provided invaluable information for this presentation: City of Indianapolis Office of the Mayor Honorable Greg Ballard, Mayor Department of Public Works David Sherman, Director Steve Nielsen, PE Chief Engineer WWT & Storm Larry Jones, PE Chief Engineer Transportation Office of Sustainability, Kären Haley, Director Indianapolis Clean Stream Team Dr. Bill Hunt, PhD, PE, North Carolina State University AMEC Elements Engineering Williams Creek EMH&T Brian Neilson 31

32 Questions? thank you Allyson Pumphrey, LEED AP Brian Neilson, PE, LEED AP Copy of presentation available via internet ftp: site upon request 7400 North Shadeland Avenue. Suite 150. Indianapolis. IN Headquarters 5500 New Albany Road. Columbus. Ohio University Executive Park Drive. Suite 231. Charlotte. NC Governor's Hill Drive. Suite 110. Cincinnati. OH Engineering Drive. Suite 150. Atlanta. GA emht.com Brian Neilson 32