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:
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3.
Rouge River National Demonstration Grant Projects
Original (1996) Long Term CSO Plan Projects
Recent Developments
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4.
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)
Recommended Future CSO Control Projects:
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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
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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 )
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Hubbell-Southfield Basin (1994):
Puritan-Fenkell Basin (1995)
7 Mile Basin (1996):
Task 1 In System Storage (1996):
St. Aubin S&D Facility (1999):
Leib S&D Facility (1999):
WWTP Expansion (2000):
Conner Creek CSO Basin (2001)
In-System Storage Devices (2002):
Baby Creek S&D Facility (2003):
Belle Isle CSO Basin (2005):
Oakwood Basin & P. Sta. (2007)
Oakwood Sewer Improvements (2008)
$ 58.9 M
$ 18.1 M
$ 14.9 M
$ 3.4 M
$ 19.8 M
$ 33.4 M
$ 101.2 M
$ 201.4 M
$ 30.8M
$ 76.1 M
$ 16.1 M
$ 168.7 M
$ 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 Tunnel
Schematic 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
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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:
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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
Guiding Principles for CSO Alternative Evaluation
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.
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:
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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
Recommended Conventional CSO Control 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
Comparison of URT and Current
Recommendation for Upper Rouge Outfalls
Original “URT”
First Flush Tank Alternative
30’ Diameter
7 Miles long
201 MG capacity
17 CSO Outfalls
100 MGD Pump Station
Includes 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 Start
Concurrent Tunnel Contracts
7 Year Construction Period
$126 M/yr Avg Cost
9 First Flush Tanks
13 Outfalls w/Disposable Net Installations
13 Chem. Storage/Pumping Sites
> 24 Chemical Injection Points
34.6 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 cost
2012 Construction Start: Pilot Projects Only
Sequential Construction Contracts
25 Year Construction Period
$20 M/yr Avg Cost
(over 7 year constr. period)
(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) :
• Oakwood Sewers Segments 2,3:
• Baby Creek Remedial Measures:
• Carbon, Fort St outfall elimination:
• TRC Minimization + In-Stream Evaluations:
• Hubbell-Southfield Improvements:
• Task 1 In-System Gate renovations:
• Pembroke outfall First Flush Pilot Project:
• RRO-2 segment 1 (WWTP work):
• Green Infrastructure Program:
PHASE I SUBTOTAL:
Const. Cost:
$44 M
$ 2M
$ 1M
$ 1M
$ 3M
$ 5M
$24 M
$30 M
$15 M
$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:
$ 3M
• RRO-2 Segment 2 (outfall conduit):
$100 M
• Re-investment in existing CSO facilities: $ 10 M
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Detroit River CSO Outfalls*:
Green Infrastructure Program:
$ 34 M
PHASE II TOTAL:
$194 M
$ 15 M
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* 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 InPipe 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)
2010
2008
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Projects:
URT (201 MG)
Oakwood Sewers
Baby Creek
Carbon/Fort St elimination
TRC Minimization
WWTP outfall (DRO-2)
Future Detroit River CSOs
TOTAL
$1,000M
$ 59M
$ 2M
$ 1M
$ 1M
$ 299M
$ 185M
$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.
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Projects:
2 Pilot Projects:
$ 41 M
Glenhurst outfall
$ 3M
Remaining Upper Rouge Outfalls $383M
Oakwood Sewers
$ 59 M
Baby Creek
$ 2M
Carbon/Fort St elimination
$ 1M
TRC Minimization
$ 1M
Task 1 Gate renovation:
$ 5M
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)
$300
$250
2008 C S O P rog ram (with Orig . UR T )
$200
$150
$100
$50
2034
2033
2032
2031
2030
2029
2028
2027
2026
2025
2024
2023
2022
2021
2020
2019
2018
2017
2016
2015
2014
2013
2012
2011
2010
2009
$0
2008
C o n s tru c tio n C o s t/Y ear ($,M)
2010 R ec ommended C S O P rog ram
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