HOW ONE SMALL COMMUNITY SAVED BIG BUCKS ON ITS CSO LONG-TERM CONTROL PLAN

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Mildred Caldwell
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1 HOW ONE SMALL COMMUNITY SAVED BIG BUCKS ON ITS CSO LONG-TERM CONTROL PLAN CITY OF WASHINGTON, INDIANA Mark L. Harrison P.E Lenin P. Kasthuri E.I.T

2 CONSTRUCTED WETLANDS: A TECHNOLOGY WHOSE TIME HAS COME Traditional Solutions Designed for Big Cities Gray vs. Green Needed Solutions for Small & Rural Cities & Sites Does Green Make More Sense? Use Mother Nature to Do the Work: Saves Energy Uses Less Chemicals Needs Less Maintenance Saves Money Provides Wildlife Habitat & Park-Like Environment

3 WHY WASHINGTON, INDIANA? Founded in 1857 as a Railroad Town Majority of Sewer System Dates to 1930s Combined Sewer Area: ~1,400 Acres Four Active CSOs Two Retention Ponds WWTP ADF: < 3.0 MGD Sustained Wet Weather Flow: 5.5 MGD Little Storage Any Rain Event Produced CSOs to Hawkins Creek Washington, Indiana Population 12,000t

Improve Quality or Address Problem in Other Neighborhoods CSOs Repeatedly

4 WHY WASHINGTON? Early Attempts Enclosed Hawkins Creek in More Affluent Area No Attempt to Improve Quality or Address Problem in Other Neighborhoods CSOs Repeatedly Pooled & Dried Up in Open Ditches Concentrating Pollutants 2001 Study Found Water Quality Exceeded Safe Levels of BOD, TSS & Ammonia

5 WATERSHED WWTP

6 CURRENT SITUATION Combined Sewer Area Approx. 1,400 Acre Two Retention Ponds Three Active CSOs WWTP Capacity - ADF < 3.0 MGD - Sustained Wet-Weather Flow 5.5 MGD Any Rain Event will result in a CSO to Hawkins Creek

7 CURRENT SITUATION 84 Railroad & Downtown Sewers 78 Hawkins Creek 78 Golf Course th Street 54 Railroad & Downtown Sewers To WWTP Pk. Flow 5.5 MGD 2-inch Rain Event Pk. Flow MGD

8 CSO 003 Outfall CSO 009 Outfall Hawkins Creek After a Rain Event Hawkins Creek After a Rain Event

9 WHY WASHINGTON? A 2002 Study Est. $39.9M to Capture & Treat CSOs By 2007, Costs Had Escalated to $53M New I-69 Promised Opportunities to Attract Jobs, If Sewer Rates Stayed Competitive with No Threat of Big Rate Hikes With 12,000 Residents & MHI of $34K, Washington Needed a Sustainable Alternative! Determined to Find It, the City Decided to Look at the Potential for Constructed Wetlands

10 MGD Conc. (mg/l) FLOW MONITORING AND WATERSHED MODELLING BOD, TSS & TKN Treatment Volume MG Pk. Fl MGD First-Flush First-Flush Total Treatment 26 TSS = 80 mg/l Partial Treatment Minutes

11 Present Worth (M) EVALUATION OF ALTERNATIVES Sewer Separation Treatment - Physical / Chemical - CEHRC / UV with Storage - CEHRC / UV without Storage Treatment Constructed Wetland - Energy Savings - Green Technology Sewer Separation Physical/ Chemical Constructed Wetland 11

DESIGN APPROACH First-Flush Retention of combined sewage flows for transportation and treatment at the WWTP Between 1-Year,1-Hour and 10-Year,1-Hour Storms (2.

12 DESIGN APPROACH First-Flush Retention of combined sewage flows for transportation and treatment at the WWTP Between 1-Year,1-Hour and 10-Year,1-Hour Storms (2.17 in) Primary treatment (30 min settling time) of combined sewage flows followed by disinfection Excess of 10-Year,1-Hour Storms Treatment of combined sewage flows to the extent possible with facilities designed for lesser flows

13 CONCEPTUAL LAYOUT STORAGE TANK & CONSTRUCTED WETLAND PS 24 FM DS Pond Rock Filter WWTP UV 36 Wetland Channel 13

14 FLOW SCHEMATIC CSO WWTP CSO CSO MG Storage Tank UV 10 MGD Wetland Channel 22 MG First-Flush CEHRC To WWTP via 24 Gravity Sewer

CULV CSO 009 PUMP STATION CSO 003 FLOW CONTROL STRUCTURE CULV DIV BOX BAR SCRN CSO STORAGE TANK (5 MG MAX) FLOW CONTROL CHANNEL CULV CSO 009 FLOW CONTROL STRUCTURE CSO 009 CSO 003

15 CULV CSO 009 PUMP STATION CSO 003 FLOW CONTROL STRUCTURE CULV DIV BOX BAR SCRN CSO STORAGE TANK (5 MG MAX) FLOW CONTROL CHANNEL CULV CSO 009 FLOW CONTROL STRUCTURE CSO 009 CSO 003 CSO 006 FOREBAY NUTRIENT BAFFLE BOX CSO 006 FLOW CONTROL STRUCTURE UV DISINFECTION GRAVEL FILTER WETLANDS Dry First Weather Flush Dry Weather First Flush Up to 10 yr/1 hr Over 10 yr/1 hr

16 CULV CSO 009 PUMP STATION CSO 003 FLOW CONTROL STRUCTURE CULV DIV BOX BAR SCRN CSO STORAGE TANK (5 MG MAX) FLOW CONTROL CHANNEL CULV CSO 009 FLOW CONTROL STRUCTURE CSO 009 CSO 003 CSO 006 FOREBAY NUTRIENT BAFFLE BOX CSO 006 FLOW CONTROL STRUCTURE UV DISINFECTION GRAVEL FILTER WETLANDS Up Over to First 10 yr/1 Flush hr Dry Weather First Flush Up to 10 yr/1 hr Over 10 yr/1 hr

17 CSO 003 Diversion Structure CSO 003 Outfall Structure CSO 003 Outfall Structure CSO 006 Outfall Structure

18 CSO 003 FLOW CONTROL STRUCTURE

19 STORAGE TANK - BASE STORAGE TANK - WALL STORAGE TANK - INSIDE VIEW STORAGE TANK - OUTSIDE VIEW

20 5 MILLION GALLON(MAX) CSO STORAGE TANK

21 Conveyance Pipes Two 84-inch Conveyance Pipes Two 84-inch

22 CONSTRUCTED WETLAND PRELIMINARY TREATMENT DUKE EASEMENT UV ROCK FILTER

23 BAFFLE BOX

24 UV & OUTFALL

25 FILL AND DRAW TYPE WETLAND Emergent / Submergent / Aquatic Vegetation INF Biodegradation PhytoDegradation Filtration Settling Clarified Effluent EFF Adsorption/Absorption Biodegradation Phyto Stabilization RhizoDegradation EPDM Liner Soil Rock Filter & UV

26 CONSTRUCTED WETLAND Forebay Pond Bank Stabilization Liner & Subsurface Drain Rock Filter

27 CSO Storage Tank CSO 009 Pump Station Forebay Rock Filter Wetland

PLANT SPECIES Early Successional Wetland Mix Grasses and Sedges Silphium perfoliatum (Cupplant) Carex frankii (Frank s Sedge) Solidago gigantean (Late Goldenrod) Carex shortiana (Short s Sedge)

(Virginia Wild Rye) Scirpus acutus (Hardstem Bulrush) Glyceria striata (Fowl Manna Grass) Scirpus valiidus (Softstem Bulrush) Leersia oryzoides (Rice Cut Grass) Panicum virgatum (Switchgrass)

28 PLANT SPECIES Early Successional Wetland Mix Grasses and Sedges Silphium perfoliatum (Cupplant) Carex frankii (Frank s Sedge) Solidago gigantean (Late Goldenrod) Carex shortiana (Short s Sedge) Solidago riddellii (Riddell s Goldenrod) Carex vulpinoidea (Fox Sedge) Verbena hastate (Blue Vervain) Elymus riparius (Riverbank Wild Rye) Vernonia fasciculate (Smooth Ironweed) Elymus virginicus (Virginia Wild Rye) Scirpus acutus (Hardstem Bulrush) Glyceria striata (Fowl Manna Grass) Scirpus valiidus (Softstem Bulrush) Leersia oryzoides (Rice Cut Grass) Panicum virgatum (Switchgrass) Spartina pectinata (Prairie Cordgrass) Alisma subcordatum (Water Plantain) Asclepias incarnate (Swamp Milkweed) Aster puniceus (Swamp Aster) Aster simplex (Panicled Aster) Boltonia latisquarna (False Aster) Cassia hebecarpa (Wild Senna) Eupatorium maculatum (Spotted Joe-Pye Weed) Eupatorium perfoliatum (Boneset) Helenium autumnale (Autumn Sneezeweed) Lycopus americanus (Water Horehound) Mimulus ringens (Monkeyflower) Penstemon digitalis (Foxglove Penstamon)

29 A SUSTAINABLE ALTERNATIVE Incorporating Wetlands Reduced Cost to $26.4M Saving Washington s Resident s $26.6M Plus $1.6M Annually in O&M Recognizing the Need for Green Sustainable Solutions, the State Provided a $9M Grant Remainder Financed at 2.81% Through SRF Resulting Rate of $34.50 per 4,000 Gallons Compared to ~$70.00 (2007) for Original Plan Potential to Add Walking Trails Water Quality Will Meet E coli Standard

30 PROJECT AREA

31 PROJECT AREA

32 ACKNOWLEDGEMENT City of Washington State Revolving Fund Program IDEM INDNR Duke Energy Vectren CSX Private Property Owners

APWA Project of the Year Subject of Recent EPA Webinar

33 WASHINGTON CSO WETLAND SYSTEM 2011 Top 10 Project Water & Wastes Digest Nominated by APWA Indiana Chapter for 2012 APWA Project of the Year Subject of Recent EPA Webinar Presented by the Indiana Department of Environmental Management

34 THANK YOU For more information contact: Mark Harrison

35 POLLUTOGRAPH AT OAK STREET OUTFALL

Detention /Urban Disturbed Wetlands 2013

Detention /Urban Disturbed Wetlands 2013 Urban Wetland/Floodplain Seed Mixture A seed mix for urban floodplains, tolerant of dirty storm water, some siltation, dolls heads, & bleach bottles. Sun or partial