City of Madison Engineering Dept. Jim Bachhuber, PH Brown and Caldwell Madison, WI

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1 Wisconsin League of Municipalities Conference Fall, 2015 Enhanced Phosphorus Removal from Stormwater --One Approach to TMDL Compliance August 4, 2015 Greg Fries, PE City of Madison Engineering Dept. Jim Bachhuber, PH Brown and Caldwell Madison, WI

2 Project Background & TMDL Requirements Madison, WI

3 Project Background & TMDL Requirements Madison, WI Madison Lakes have been researched for more than 100 years Edward Birge and Chauncy Juday (1917)

4 Project Background & TMDL Requirements Madison, WI Despite decades of pollution management p p g Lakes can become hyper-eutrophic

5 Why does Madison want to do this?

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7 Project Background & TMDL Requirements Madison, WI Rock River Basin TMDL Completed in 2011 Set WLA s & LA s for TSS & TP Madison MS4 Requirements: TP Reduction: 16,000 lbs./yr. Equal to ~ 55 % City-wide TP reduction from MS4 Madison

8 Background Why propose chemical treatment? City of Madison is a permitted MS4 with about 16,400 LBS of P to remove to meet the TMDL requirements Ponds are extremely expensive (1.2 million for our last one that removes about 250 lbs of TP/Year or $240/LB/year) and they don t remove that much TP. We are partners with Madison Metropolitan Sewerage District in the Adaptive Management Pilot program known as Yahara WINS but.. The City would like to address as much of our TP reduction as possible within our municipal boundary where it is cost effective.

9 Pilot Project Marion Dunn Pond Madison, WI Watershed Info: Madison Area 232 acres Medium Density Residential No treatment other than sweeping besides the pond

10 Site Location/Layout Inlet 4.5 x8.0 CBC Marion Dunn Pond East Outlet 42 RCP West Outlet 42 RCP Marion Dunn Pond watershed (Midvale Ave is the (left) boundary)

11 Site Location/Layout Inlet 4.5 x8.0 CBC Marion Dunn Pond East Outlet 42 RCP West Outlet 42 RCP Marion Dunn Pond Aerial courtesy of Google Maps Aerial courtesy of Bing Maps

12 Marion Dunn Pond August 2013 Abundant algae and other aquatic plants indicates high levels of available phosphorus and nitrogen in Marion Dunn Pond. Trees have been removed from the pond berm per UW request.

13 Inlet Concrete Box Culvert USGS monitoring shed Concrete Box Culvert Inlet

14 Treatment System Design Main Shed Final Shed Design (Crane Engineering) g) Shed (Monroe St in background) July 6,

15 Site Photos

16 Site Photos Inlet 4.5 x8.0 CBC Marion Dunn Pond West Outlet 42 RCP

17 Site Photos Inlet 4.5 x8.0 CBC Marion Dunn Pond West Outlet 42 RCP

18 Existing Pond Water Quality Historical Values Baseline Values Parameter Unit Average Historical Value ( ) Total P μg/l Ortho P μg/l Hardness (Total as CaCO3) mg/l 20.5 ph (Lab) ph units 7.0 Alkalinity (Total as CaCO3) mg/l Date Location Al E Coli Diss. NH (MPN/ 3 -N NO x -N Org. N Total N Total P TSS Sulfate (µg/l) µg/l µg/l µg/l (µg/l) (mg/l) (mg/l) 100 ml) µg/l 5/28/13 MD CBC , /30/13 MD CBC , /10/13 MD CBC ,

19 2014 Results TSS and TP Event TSS TP Flow Volume TSS in TSS out TP Reduction in TP out Reduction (cfs) (lbs) (lbs) (lbs) (lbs) (%) (%) August 19, ,255 1, % % August 21, ,621 1, % % August 25, ,297 1, % % September 4, ,690 2, % % September 10, 80, % %

20 2014 Results Compared to WinSLAMM Estimates TSS Reduction TP Reduction WinSLAMM Predicted TP Event (%) (%) Reduction (%) August 19, % 69% 63% August 21, % 28% 56% August 25, % 29% 55% September 4, % 41% 57% September 10, % 58% 61%

21 2015 Results TSS and TP TSS TP Flow Volume TSS Event in TSS out TP Reduction in TP out Reduction (cfs) (lbs) (lbs) (lbs) (lbs) (%) (%) June 11, ,916 1, % % July 6, , , % % July 17, ,994 1, % % July 29, ,968 1, % % August 17-18, ,790 5, % % August 28, , % % September 8, , % %

22 2015 Results Compared to WinSLAMM Estimates TSS Reduction TP Reduction WinSLAMM Predicted TP Event (%) (%) Reduction (%) June 11, % 20% 53% July 6, % 51% 56% July 17, % 70% 58% July 29, % 47% 44% August 17-18, % 58% 58% August 28, % 51% 47% September 8, % 54% 56%

23 Next Steps Continue to monitor, collect samples for the remainder of the warm season Hope to get one sample during leaf season Shut down system for winter in early November Discuss coagulant and dosing options for last season of operation (2016) Aluminum chlorlhydrate Re-commission system in April-May 2016

24 Feasibility Study Starkweather Creek Brown and Caldwell 24

25 Project Background Basic Concept Stormwater Phosphorus Control Through Coagulant Treatment Coagulant >

26 Project Setting Lake Mendota Watershed Location

27 Project Setting East Fork Starkweather Cr: Watershed = 5,410 ac. Land Use: Urban: 68% Rural: 32% Recording Rain Gauges

28 Project Challenges Big Picture New Idea 1st full scale project Public Acceptance Strong Friends Group Regulatory Acceptance How to Permit Coagulant Concerns Quarry Pond Lake Monona

29 Project Site

30 Coagulant Testing Field Sampling: 6 Runoff Events test total of 5 coagulants. Consult 3 real-time recording rain gauges (NOAA and USGS). Equal Width Increment sampling Capture spring and summer conditions. Capture enough volume for 3 coagulant types at each event. Test each coagulant at 3 concentrations of Al Brown and Caldwell 30

31 Coagulant Testing Schematic of Coagulant Testing Lab Procedure Brown and Caldwell 31

32 Coagulant Testing Lab Procedure Setup ID system Churn split samples Analyze raw samples at time 0 Add coagulants Test ph and photograph At 24 hour, analyze all jars Brown and Caldwell 32

33 Coagulant Testing Visual Results April 9, 11:40 (24 hr.) Coag 4137 (PAC) Brown and Caldwell 33

34 Coagulant Testing Visual Results April 14, 2015 (5 days) All Coagulants Brown and Caldwell 34

35 Coagulant Testing Aluminum Chlorohydrate (ACH); 12.59% Aluminum Round Date/ Coagulant Concentration Time 0 Total P (mg/l) Time + 24 hrs. % Change from 0 hr. (%) Raw Sample % 3 mg/l Al % 6 mg/l Al % 9 mg/l Al % Raw Sample % 4 mg/l Al % 6 mg/l Al % 8 mg/l Al % Raw Sample % 4 mg/l Al % 6 mg/l Al % 8 mg/l Al % Raw Sample % 4 mg/l Al % 6 mg/l Al %

36 Hydrologic and Hydraulic Modeling Treatment Volume Scenarios Treat runoff flows < 100 cfs Treat runoff flows < 150 cfs Treat runoff flows < 50 cfs

37 Hydrologic and Hydraulic Modeling Treatment Volume Scenarios 100% 90% 80% Runoff Volume Captured at Various Diversion Flow Rates (10-Yr Period) of Total Run noff Volume % 70% 60% 50% 40% 30% 20% 10% 0% Maximum Diversion Flow (cfs) Avg. Min. Max.

38 Phosphorus Control Potential Coagulant Treated Runoff Avg. TP TP Load Diversion TP Load Treatment Volume Concentration Reduction Rate (lbs./yr.) Effectiveness (ac. ft./yr) (mg/l) (lbs./yr.) (%) 25 cfs 1, ,328 85% 1, cfs 2, ,843 85% 1, cfs 3, ,149 85% 1, cfs 3, ,355 85% 2, cfs 3, ,506 85% 2, cfs 3, ,621 85% 2,228 ~ 7% - 14% of City s Total MS4 Target City of Madison overall TMDL - MS4 phosphorus reduction goal: 16,000 lbs /yr

39 Next Steps: Finalize Coagulant Selection Evaluate cold weather performance of coagulants Obtain historical and current pricing Obtain cold weather storage information

40 Next Steps: Preliminary Design Key Project Components 1. Flow Diversion 2. Coagulant Dosing / Instrumentation 3. Coagulant Storage 4. Monitoring & Controls 5. Floc Removal and Disposal Brown and Caldwell 40

41 Next Steps: Challenges / Concerns: Diversion Structure (fish & recreation passage) Floodplain Construction? Possible Individual WPDES permit Coagulant Concerns: Impacts on water ph Metals availability Brown and Caldwell 41

42 Questions? Greg Fries, PE City of Madison Engineering Dept. Jim Bachhuber, PH Brown and Caldwell Madison, WI