UPDATE ON DWSDS LONG TERM CSO CONTROL PLAN

Presented to:Board of Water CommissionersMay 12, 2010

Topics to be CoveredSystem Configuration Before CSO Controls (pre-1995)CSO Controls 1995 2008:Rouge River National Demonstration Grant ProjectsOriginal (1996) Long Term CSO Plan ProjectsRecent DevelopmentsSubmittal of Long Term CSO Plan Update (October, 2008)Financial Crisis: Termination of URT($1 B) and DRO-2 ($300 M)Analysis of less costly CSO Alternatives (2009 2010)Recommended Future CSO Control Projects:Future Rouge River CSO Control FacilitiesGreen Infrastructure ProgramFuture Detroit River CSO Control Facilities

Pre-1995 CSO Discharges in Detroit76 permitted outfalls (33 to Rouge River and 43 to Detroit River)~ 50 discharge events/year (average);~ 20 billion gallons discharged/year;Major impact on Rouge River water quality:Dissolved Oxygen depletionBacteria exceedancesSediment deposits and bank erosionLesser impacts on Detroit River:Bacteria exceedances

Location of Pre-1995 CSO Outfalls

1989 NPDES Permit:Original CSO Control Requirements1989 NPDES Permit initially required ALL Rouge River CSO Outfalls to be treated/disinfected by Retention Treatment Basins by August, 2005;DWSD contested the permit and then negotiated a settlement requiring:3 Demonstration Basins: Hubbell-Southfield; Puritan-Fenkell and 7 Mile West (constructed in 1995-1996);6 In-System Storage Task 1 control gates (installed 1996)Prepare a Long Term CSO Control Plan (submitted July, 1996)

1996 Long Term CSO Control Plan Recommended ProjectsWWTP Primary Treatment Capacity Increase Conner Creek CSO BasinLeib Screening & Disinfection FacilitySt. Aubin Screening & Disinfection FacilityBaby Creek Screening & Disinfection FacilityUpper Rouge CSO Tunnel (URT)Additional In-System storage gatesBelle Isle CSO Basin*Oakwood CSO Basin, P. Station & Sewer Improvements** Projects added after the Long Term Plan was submitted in 7/96

Detroits CSO Facilities(as of 2008)

CSO Project Costs(Construction Start )Hubbell-Southfield Basin (1994): $ 58.9 MPuritan-Fenkell Basin (1995)$ 18.1 M7 Mile Basin (1996):$ 14.9 MTask 1 In System Storage (1996): $ 3.4 MSt. Aubin S&D Facility (1999): $ 19.8 MLeib S&D Facility (1999):$ 33.4 MWWTP Expansion (2000):$ 101.2 MConner Creek CSO Basin (2001)$ 201.4 MIn-System Storage Devices (2002):$ 30.8MBaby Creek S&D Facility (2003): $ 76.1 MBelle Isle CSO Basin (2005):$ 16.1 MOakwood Basin & P. Sta. (2007)$ 168.7 MOakwood Sewer Improvements (2008) $ 15.0 M$1,593 M

Benefits of CSO Control Program

October, 2008 Update to Long Term CSO Control PlanAssumed completion of URT tunnel by 2015 (construction to begin on 1st tunnel segment in 2008)

Recommended that 41 Detroit River CSO outfalls be controlled with innovative Disposable Net + In-Pipe Disinfection technology

Work to be undertaken over 20 year period: 2010 2030 Estimated construction cost = $ 185 M (2009 $)

MDNRE informally expressed concurrence with the Plan recommendations, but has not responded in writing

Original Upper Rouge CSO TunnelSchematic Drawing

Key Facts re: Upper Rouge CSO Tunnel30 diameter tunnel; 7 miles long; 150 underground215 million gallons capacityWould reduce CSO discharges to < 1/yearControls 17 Detroit CSOs and 11 suburban CSOs Includes 100 mgd Pump Station and 14 Drop Shafts 10 surge control surface structures in Rouge ParkConstruction period: 2008 2015Construction cost = $880 million as of 2/09; expected to escalate to $1 billion after all 8 contracts bid83% of costs allocated to Detroit customers

Projected CSO Debt Load with URT Tunnel

DWSDs Permit Modification Request due to Economic HardshipMDNRE approval sought to eliminate URT Project and DRO- 2 Outfall based on economic hardship, including:Population Decline/Loss of Customer BaseJob Losses and Manufacturing DeclinesHousing Data: SEV, Taxable ValueWater Sales; Projected Revenues and Rates Actual CSO Control Project Expenditures >> EstimatesDetroit sewer costs as a % of Median Annual Household Income > EPAs 2% threshold for affordability

NPDES Permit Requirement re: Study of CSO Control AlternativesDWSD required to analyze alternative CSO ControlsInitial report due: December 15, 2009Initial recommendation: Build $484 M smaller CSO tunnel (URT-2) with ~ 3.2 untreated overflows/yrMDNRE requests 90 day Supplemental Study to examine other alternatives to avoid dispute on approvability of URT-2 recommendationSupplemental Report submitted April 30, 2010

Reduce capital cost as much as possible;Utilize an extended implementation schedule to reduce impact on rate payers and allow time for Detroits economic recovery;Minimize O&M costs by limiting the number of new CSO facilities;Achieve in-stream water quality comparable to what would have resulted from the URT project;Incorporate Green Infrastructure activities to the extent they are feasible, cost effective and beneficial (i.e. reduce or retard runoff);Consider the cost impacts of ongoing projects (Oakwood, Baby Creek remedial measures, TRC Minimization, etc.) as part of the overall CSO program implementation schedule.Guiding Principles for CSO Alternative Evaluation

Alternatives Evaluated by DWSDConventional CSO Technologies:Storage TunnelsRetention Treatment BasinsVertical Shafts West Arm Interceptor ExtensionScreening & DisinfectionFirst Flush TanksDisposable Nets w/DisinfectionVortex SeparatorsIn-System Storage

Green Infrastructure Options:Downspout disconnectionRe-vegetate vacant lotsBioswales & rain gardensRain BarrelsGreen roofsTree planting/Urban ForestDemolish abandoned structuresPorous PavementCurb bump outsRoadside Tree Trenches

Supplemental Report RecommendationsReplace URT tunnel with a series of innovative, end-of-pipe treatment systems consisting of:First Flush storage tanks at multiple outfallsConnecting sewers to eliminate small outfallsDisposable Net installations to screen out sanitary trashDisinfection by chemical injection of NaOCl into existing sewers far enough upstream from overflow point to allow contact time for effective bacteria killLimit capital expenditures for CSO Projects to < $35 M/yr to stay within Detroits Financial CapabilityEstablish a 25 year schedule for program (including both Rouge River and Detroit River CSO outfalls)Implement a Green Infrastructure program to reduce stormwater flow tributary to combined systemDemonstrate new CSO control technology with Pilot Projects

Ongoing Projects ($63 Million):Oakwood Sewer Improvements (3 remaining segments): $59 MBaby Creek Remedial Measures (NaOCl feed, mech. mixers, emerg. bypass): $3 MTRC Minimization & In-Stream Assessments: $1 M

New Projects ($791Million):Hubbell-Southfield Basin Improvements: $3 MTask 1 In System Gate renovations: $5MCarbon, Fort St. Outfall eliminations: $1 M2 Pilot Projects (First Flush Tank + Disp. Nets w/disinf.) @ 7 Mile East & Pembroke: $41MGlenhurst outfall diversion and pump station: $3 MReplace URT Tunnel with First Flush Tank/Disposable Net/In-Pipe Disinfection @ 383 MRRO-2 shallow conduit in lieu of DRO-2 outfall (2 construction contracts): $130 MRe-invest in existing CSO Control Facilities: $40 MControl of Detroit River CSO Outfalls using Disposable Nets/In-Pipe Disinfection @ $185M

Recommended Conventional CSO Control Projects

Comparison of URT and Current Recommendation for Upper Rouge OutfallsOriginal URT30 Diameter7 Miles long201 MG capacity17 CSO Outfalls100 MGD Pump StationIncludes Redford, Dearborn Hts flow 1 Overflow/yr (untreated)850,000 gal/yr discharged (untreated)$880 Million capital cost$1.5 Million annual O & M cost2008 Construction StartConcurrent Tunnel Contracts7 Year Construction Period$126 M/yr Avg Cost(over 7 year constr. period)

First Flush Tank Alternative9 First Flush Tanks13 Outfalls w/Disposable Net Installations13 Chem. Storage/Pumping Sites> 24 Chemical Injection Points34.6 MG capacityIncludes Redford, Dearborn Hts flow~ 13 Overflows/yr (treated)1.2 B gal/yr discharged (treated)$ 426 Million capital cost$2.83 Million annual O & M cost2012 Construction Start: Pilot Projects OnlySequential Construction Contracts25 Year Construction Period$20 M/yr Avg Cost(over 25 year constr. period)

Recommended Green Infrastructure Program Rationale for including Green Infrastructure:Expected to reduce inflow to combined sewers by at least 10% - 20% upon completion;Provides quick water quality benefit while conventional CSO facilities are designed, sited, financed and built;Acknowledges the ongoing demographic and population changes that are profoundly affecting the tributary area;Consistent with the Mayors objective to remove abandoned homes and deal with urban blightConsistent with approach being used in many other urban areas (Philadelphia, Portland, Cincinnati, Washington D.C.)

Proposed Green Infrastructure Activities Disconnect residential downspouts and, where feasible, commercial and industrial downspouts; Demolish and remove vacant structures, seal pipes and re-vegetate the parcel to return it to pervious cover;Use bioswales and tree trenches along roadways and parking lots to intercept runoff and reduce stormwater inputs;Plant trees for uptake and evapotranspiration along roadways and open spaces;Implement activities on municipally-owned land, focusing on managing stormwater runoff in under-utilized parks

Phasing Of Recommended ProjectsProposed Implementation Schedule: > 25 years (beyond 2034);Stage Projects in multiple 5-Year Phases;Spread out new CSO Project construction to average

Recommended Phase I CSO Control Projects(2010 2014)PHASE I (2010-2014) : Const. Cost: Oakwood Sewers Segments 2,3: $44 MBaby Creek Remedial Measures: $ 2 MCarbon, Fort St outfall elimination: $ 1 MTRC Minimization + In-Stream Evaluations: $ 1 MHubbell-Southfield Improvements: $ 3 MTask 1 In-System Gate renovations: $ 5 MPembroke outfall First Flush Pilot Project: $24 MRRO-2 segment 1 (WWTP work):$30 MGreen Infrastructure Program:$15 M

PHASE I SUBTOTAL:$125 M

Recommended Phase II CSO Control Projects(2015 2019)PHASE II (2015-2019): Const. Cost: Oakwood Sewers Segment 4:$ 15 M7 Mile East Pilot Project:$ 17 MGlenhurst Pump Station/Diversion:$ 3 MRRO-2 Segment 2 (outfall conduit):$100 MRe-investment in existing CSO facilities:$ 10 MDetroit River CSO Outfalls*:$ 34 MGreen Infrastructure Program:$ 15 M PHASE II TOTAL:$194 M

* specific outfalls to be undertaken in Phase II not yet identified

Future Phases (2020 and beyond)Continue Green Infrastructure Program through 2029 @ $2 M/Yr ($50 M total Green investment);

Continue re-investment in existing CSO Control Facilities;

Undertake new CSO Control Facilities along Rouge River and Detroit River based on re-evaluation of Detroits Financial Capability every 5 years (presumably Disposable Nets with In-Pipe Disinfection Systems assuming Pilot Projects demonstrate that the new technology performs as expected)

Factors That Could Affect CSO Schedule Time period needed by Detroit to achieve economic recovery;Financial solvency of the City and ability to sell bonds to finance capital improvements;Demographic changes in the tributary area which affect wet weather flows;Green Infrastructure progress and stormwater flow reductions actually achieved;Availability of low interest SRF loan money or grant funding;Expenditures needed for new regulatory requirements (e.g. de-chlorination);Need for additional re-investment in existing CSO facilities;Cost of non-CSO capital improvement projects

Comparison: Then and Now(2008 vs 2010 CSO Program Costs)

2008 Projects:URT (201 MG)$1,000MOakwood Sewers$ 59MBaby Creek$ 2MCarbon/Fort St elimination$ 1MTRC Minimization$ 1MWWTP outfall (DRO-2) $ 299MFuture Detroit River CSOs$ 185M TOTAL $1,547M

Average Cost/Yr 2008 - 2015: $169 M/yr

Note: 2008 CSO Program did not included a budget for ongoing re-investment in existing CSO facilities.

2010 Projects:2 Pilot Projects: $ 41 MGlenhurst outfall $ 3 MRemaining Upper Rouge Outfalls $383MOakwood Sewers $ 59 MBaby Creek $ 2MCarbon/Fort St elimination $ 1MTRC Minimization $ 1MTask 1 Gate renovation: $ 5 MRRO-2 outfall $130MRe-invest in CSO Facilities $ 43MFuture Detroit River CSOs $185M SUBTOTAL $ 853 MGreen Infrastructure $ 50 MTOTAL $ 903 M

Average Cost/Yr 2008 - 2015: $ 21 M/yr

Comparison of 2008 and 2010 CSO Control Programs(estimated construction cost/yr)

2008 vs 2010 CSO Program

010

0163

15258

15266

31252

43201

21130

4890

5710

4522

4526

440

370

3625

3735

3625

3715

3617

370

360

370

360

350

340

350

340

340

2010 Recommended CSO Program

2008 CSO Program (with Orig. URT)

Construction Cost/Year ($,M)

Sheet1

Rouge River CSO Control Progam

Recommended Projects: Cost by Year and Phasing Schedule

Facility200820092010201120122013201420152016201720182019202020212022202320242025202620272028202920302031203220332034

PHASE I: 2010 - 2014

1Oakwood Sewers Seg #2 (PCS-80)$8$4

2Baby Creek remedial imprvmts$3

3Carbon, Fort St Outfall Elimination$1

4TRC Min + In-Strm Evals$1

5$20$12

6Hubbell-Southfld remedial impvts$2

77 Mile East: FFT+DispNets+NaOCl$5$9$3

8Pembroke: FFT only$5$10

9Glenhurst diversion + P Sta$3

10Phase I Green Infrastr. Projects$3$3$3$3$3

Phase I Subtotal

PHASE II: 2015 - 2020

11Oakwood Sewers Seg #4$5$10

12Pembroke: Disp Nets + NaOCl$9

13RRO-2: WWTP gates + I&C$20$10

14URT-2 South Tunnel (incl. adits)$19$40$40$40

15Re-investment in existing CSO fac's$2$2$2$2$2

16Phase II Green Infrastr. Projects$3$3$3$3$3

Phase II Subtotal

PHASE III: 2020 - 2024

17URT-2 S Tunnel: Dr Shfts + Nr Surf.$20$20$23$20

1835 mgd URT-2 dewatering P. Sta.$25$30

19Re-investment in existing CSO fac's$2$2$2$2$2

20Phase III Green Infrastr. Projects$2$2$2$2$2

Phase III Subtotal

PHASE IV: 2025 - 2029

21URT-2 North Tunnel (incl. adits)$30$35$40$28

22URT-2 N Tunnel: Dr Shfts + Nr Surf.$14$30$30

23Re-investment in existing CSO fac's$2$2$2$2$2

24Phase IV Green Infrastr. Projects$2$2$2$2$2

Phase IV Subtotal

PHASE V: 2030 and beyond

25RRO-2 Outfall Conduit + chlor/de-chlor$25$40$35

26Re-investment in existing CSO fac's$2$2$2$2$2

Phase V Subtotal

200820092010201120122013201420152016201720182019202020212022202320242025202620272028202920302031203220332034

2010 Recommended CSO Program$0$0$15$15$31$43$21$48$57$45$45$44$37$36$37$36$37$36$37$36$37$36$35$34$35$34$34$901

2008 CSO Program (with Orig. URT)$10$163$258$266$252$201$130$90$10$22$26$0$0$25$35$25$15$17$0$0$0$0$0$0$0$0$0$1,545

1000Orig. URT$10$110$170$170$170$155$130$85$1,000

299DRO-2$45$80$80$60$34$299

59Oakwood$8$4$8$12$12$5$10$59

2Baby Creek$2$2

1Carbon/Fort St$1$1

1TRC Min + In-Strm Evals$1$1

185Detroit River CSOs81022262535251517$183

1547

41Pilot Projects10104107$41

3Glenhurst3$3

383First Flush/Nets/NaOCL Rouge2322232223222322232223222322232223$383

59Oakwood$8$4$8$10$14$5$10$59

2Baby Creek2$2

1Carbon Fort St1$1

1TRC min + in stream evals1$1

5Task 1 gates5$5

130RRO-21020304030$130

43CSO Fac re-invest322222222222222222222$43

50Green Infrastructure33333333332222222222$50

185Detroit River CSOs171710101010101010101010101010109$183

903

$1,370$171

$173$22

Sheet2

Sheet3

Next StepsMeet with MDNRE to negotiate CSO project schedulesMDNRE to modify NPDES Permit with new CSO project scheduleDesign Pembroke Pilot Project for First Flush Tank + Disposable Net + In-Pipe Disinfection SystemDesign new RRO-2 outfall (1st segment @ WWTP)Develop and implement Green Infrastructure program (with other City Departments)Complete TRC Minimization Program and evaluate alternative disinfection systems

Questions

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