UPDATE ON DWSD’S

LONG TERM CSO CONTROL PLAN

Presented to:Board of Water Commissioners

May 12, 2010

Topics to be Covered

1. System Configuration Before CSO Controls (pre-1995)

2. CSO Controls 1995 – 2008:• Rouge River National Demonstration Grant Projects• Original (1996) Long Term CSO Plan Projects

3. Recent Developments• Submittal 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)

4. Recommended Future CSO Control Projects:• Future Rouge River CSO Control Facilities• Green Infrastructure Program• Future Detroit River CSO Control Facilities

Pre-1995 CSO Discharges in Detroit

• 76 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 depletion Bacteria exceedances Sediment deposits and bank erosion

• Lesser impacts on Detroit River: Bacteria exceedances

Location of Pre-1995 CSO Outfalls

1989 NPDES Permit:Original CSO Control Requirements

• 1989 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 Projects

• WWTP Primary Treatment Capacity Increase • Conner Creek CSO Basin• Leib Screening & Disinfection Facility• St. Aubin Screening & Disinfection Facility• Baby Creek Screening & Disinfection Facility• Upper Rouge CSO Tunnel (“URT”)• Additional In-System storage gates• Belle Isle CSO Basin*• Oakwood CSO Basin, P. Station & Sewer Improvements*

* Projects added after the Long Term Plan was submitted in 7/96

Detroit’s CSO Facilities(as of 2008)

CSO Project Costs(Construction Start )

• Hubbell-Southfield Basin (1994): $ 58.9 M• Puritan-Fenkell Basin (1995) $ 18.1 M• 7 Mile Basin (1996): $ 14.9 M• Task 1 In System Storage (1996): $ 3.4 M• St. Aubin S&D Facility (1999): $ 19.8 M• Leib S&D Facility (1999): $ 33.4 M• WWTP Expansion (2000): $ 101.2 M• Conner Creek CSO Basin (2001) $ 201.4 M• In-System Storage Devices (2002): $ 30.8M• Baby Creek S&D Facility (2003): $ 76.1 M• Belle Isle CSO Basin (2005): $ 16.1 M• Oakwood Basin & P. Sta. (2007) $ 168.7 M• Oakwood Sewer Improvements (2008) $ 15.0 M

$1,593 M

Benefits of CSO Control Program

October, 2008 Update to Long Term CSO Control Plan

• Assumed 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 Tunnel

• 30′ diameter tunnel; 7 miles long; 150’ underground• 215 million gallons capacity• Would reduce CSO discharges to < 1/year• Controls 17 Detroit CSOs and 11 suburban CSOs • Includes 100 mgd Pump Station and 14 Drop Shafts• 10 surge control surface structures in Rouge Park• Construction period: 2008 – 2015• Construction cost = $880 million as of 2/09; expected to

escalate to $1 billion after all 8 contracts bid• 83% of costs allocated to Detroit customers

Projected CSO Debt Load with URT Tunnel

DWSD’s Permit Modification Request due to Economic Hardship

MDNRE approval sought to eliminate URT Project and DRO- 2 Outfall based on economic hardship, including:

• Population Decline/Loss of Customer Base• Job Losses and Manufacturing Declines• Housing Data: SEV, Taxable Value• Water Sales; Projected Revenues and Rates • Actual CSO Control Project Expenditures >> Estimates• Detroit sewer costs as a % of Median Annual Household

Income > EPA’s 2% threshold for “affordability”

NPDES Permit Requirement re: Study of CSO Control Alternatives

• DWSD required to analyze alternative CSO Controls• Initial report due: December 15, 2009• Initial recommendation: Build $484 M smaller CSO

tunnel (“URT-2”) with ~ 3.2 untreated overflows/yr• MDNRE requests 90 day Supplemental Study to

examine other alternatives to avoid dispute on approvability of URT-2 recommendation

• Supplemental Report submitted April 30, 2010

1. Reduce capital cost as much as possible;

2. Utilize an extended implementation schedule to reduce impact on rate payers and allow time for Detroit’s economic recovery;

3. Minimize O&M costs by limiting the number of new CSO facilities;

4. Achieve in-stream water quality comparable to what would have resulted from the URT project;

5. Incorporate “Green Infrastructure” activities to the extent they are feasible, cost effective and beneficial (i.e. reduce or retard runoff);

6. 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 DWSD

Conventional CSO Technologies:• Storage Tunnels• Retention Treatment Basins• Vertical Shafts• West Arm Interceptor Extension• Screening & Disinfection• First Flush Tanks• Disposable Nets w/Disinfection• Vortex Separators• In-System Storage

Green Infrastructure Options:• Downspout disconnection• Re-vegetate vacant lots• Bioswales & rain gardens• Rain Barrels• Green roofs• Tree planting/Urban Forest• Demolish abandoned structures• Porous Pavement• Curb bump outs• Roadside Tree Trenches

Supplemental Report Recommendations

• Replace URT tunnel with a series of innovative, end-of-pipe treatment systems consisting of: First Flush storage tanks at multiple outfalls Connecting sewers to eliminate small outfalls Disposable Net installations to screen out sanitary trash Disinfection by chemical injection of NaOCl into existing sewers far enough

upstream from overflow point to allow contact time for effective bacteria kill• Limit capital expenditures for CSO Projects to < $35 M/yr to stay within

Detroit’s Financial Capability• Establish 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 system• Demonstrate new CSO control technology with Pilot Projects

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

New Projects ($791Million):• Hubbell-Southfield Basin Improvements: $3 M• Task 1 In System Gate renovations: $5M• Carbon, Fort St. Outfall eliminations: $1 M• 2 Pilot Projects (First Flush Tank + Disp. Nets w/disinf.) @ 7 Mile East & Pembroke: $41M• Glenhurst outfall diversion and pump station: $3 M• Replace URT Tunnel with First Flush Tank/Disposable Net/In-Pipe Disinfection @ 383 M• RRO-2 shallow conduit in lieu of DRO-2 outfall (2 construction contracts): $130 M• Re-invest in existing CSO Control Facilities: $40 M• Control 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 Outfalls

Original “URT”30’ Diameter7 Miles long

201 MG capacity17 CSO Outfalls

100 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 cost

2008 Construction StartConcurrent Tunnel Contracts7 Year Construction Period

$126 M/yr Avg Cost(over 7 year constr. period)

First Flush Tank Alternative9 First Flush Tanks

13 Outfalls w/Disposable Net Installations13 Chem. Storage/Pumping Sites

> 24 Chemical Injection Points34.6 MG capacity

Includes 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 Only

Sequential 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 Mayor’s objective to remove abandoned

homes and deal with urban blight• Consistent 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 Projects

• Proposed Implementation Schedule: > 25 years (beyond 2034);• Stage Projects in multiple 5-Year Phases;• Spread out new CSO Project construction to average <$35 Million per

year as a target “manageable” level of new debt;• Accelerate funding of Green Infrastructure projects early in the

implementation plan to achieve immediate beneficial results while conventional facilities are designed and built;

Green Infrastructure Budget Recommendation:• $3 Million/Year for first 10 years (2010 – 2019)• $2 Million/Year for next 10 years (2020 – 2029)

In addition to these DWSD sewer revenues, also pursue grants, loans, support from foundations and private stakeholders

Recommended Phase I CSO Control Projects(2010 – 2014)

PHASE I (2010-2014) : Const. Cost: • Oakwood Sewers Segments 2,3: $44 M• Baby Creek Remedial Measures: $ 2 M• Carbon, Fort St outfall elimination: $ 1 M• TRC Minimization + In-Stream Evaluations: $ 1 M• Hubbell-Southfield Improvements: $ 3 M• Task 1 In-System Gate renovations: $ 5 M• Pembroke outfall First Flush Pilot Project: $24 M• RRO-2 segment 1 (WWTP work): $30 M• Green 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 M• 7 Mile East Pilot Project: $ 17 M• Glenhurst Pump Station/Diversion: $ 3 M• RRO-2 Segment 2 (outfall conduit): $100 M• Re-investment in existing CSO facilities: $ 10 M• Detroit River CSO Outfalls*: $ 34 M• Green 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 Detroit’s 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) $1,000M• Oakwood Sewers $ 59M• Baby Creek $ 2M• Carbon/Fort St elimination $ 1M• TRC Minimization $ 1M• WWTP outfall (DRO-2) $ 299M• Future 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 M• Glenhurst outfall $ 3 M• Remaining Upper Rouge Outfalls $383M• Oakwood Sewers $ 59 M• Baby Creek $ 2M• Carbon/Fort St elimination $ 1M• TRC Minimization $ 1M• Task 1 Gate renovation: $ 5 M• RRO-2 outfall $130M• Re-invest in CSO Facilities $ 43M• Future Detroit River CSOs $185M SUBTOTAL $ 853 M• Green Infrastructure $ 50 M

TOTAL $ 903 M

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

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

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2010 R ec ommended C S O P rog ram

2008 C S O P rog ram (with Orig . UR T )

Next Steps

• Meet with MDNRE to negotiate CSO project schedules• MDNRE to modify NPDES Permit with new CSO project

schedule• Design Pembroke Pilot Project for First Flush Tank +

Disposable Net + In-Pipe Disinfection System• Design 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