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CSOs in the Rouge River and Detroit
River Watersheds
Detroit River Lighthouse,
photo courtesy of the Friends
of the Detroit River
Phil Argiroff, DEQ-WRD
January 12, 2015 1
Acronyms CSO: Combined Sewer Overflow
SSO: Sanitary Sewer Overflow
WQS: Water Quality Standards
RTB: Retention Treatment Basin
DO: Dissolved Oxygen
TRC: Total Residual Chlorine
NPDES: National Pollutant Discharge Elimination System
RAP: Remedial Action Plan
WWTP: Wastewater Treatment Plant
MDD: Million Gallons per Day
GI: Green Infrastructure
ACO: Administrative Consent Order
O&M: Operations and Maintenance
TSS: Total Suspended Solids
TP: Total Phosphorus
CBOD5: Carbonaceous Biochemical Oxygen Demand
CAFO: Concentrated Animal Feeding Operations
MAEAP: Michigan Agriculture Environmental Assurance Program
S/D: Screening/Disinfection Treatment Facility
LTCP: Long-Term CSO Control Plan
2
Water Resources
Protect and Monitor
4 Great Lakes
3,288 miles of Great
Lakes shoreline
11,000 inland lakes
36,000 river miles
5.5 million acres of wetlands
70,000 acres of critical dunes
For swimming, fishing, drinking water and aquatic ecosystems.
3
Major Impact of CSOs on Water Quality
Impact public health because CSO contain raw
sewage
Impact fisheries and aquatic organisms by
depressing dissolved oxygen
Impact from nutrients
Impact aesthetics due to sanitary trash
4
5
Wet Weather – Uncontrolled CSOs
Typical Uncontrolled CSO
WWTP
Storm Sewer
Sanitary Sewer
Combined Sewer
Michigan’s CSO Control Program
Refocused in 1988; based on revised WQS in
1986 to protect all waters for total body contact
CSO Control Manual (1994) documented a
phased program; revised WQS led to all
discharges with sewage needing disinfection
Municipalities must either:
eliminate the CSO through sewer separation, or
provide adequate treatment to meet all water quality
standards (WQS) at times of discharge
6
Adequate Treatment
Presumptive definition • complete capture of the 1 yr–1 hr event
• 30 min of detention of the 10 yr–1 hr event, for
screening, settling, skimming, and disinfection
Demonstration approach • allows evaluation that treated discharges, across a
range of events, meet WQS at times of discharge
Typical treatment is a Retention Treatment
Basin (RTB)
7
Demonstration Criteria
Refined in 1998 for Rouge River; “Criteria
for Success in CSO Treatment”
• Eliminate raw sewage
• Protect public health
• Meet the DO standard
• Control TRC
• Ensure health of biological communities
Now used statewide
8
Some Historical Notes
1985 Rouge RAP called for CSO correction by
2005 to protect public health and eliminate raw
sewage, and meet all WQS sometime after.
Contested 1988 NPDES CSO permits were
resolved in Federal Court (Judge Feikens).
Resulted in Bulkley Agreement which was a
demonstration approach.
Led to Rouge River National Wet Weather
Demonstration Project.
The 2007-8 recession led to extended correction
schedules.
9
Oakland County CSO Control
3 demonstration RTBs constructed to treat
wastewater from 38 CSOs; Acacia Park RTB,
Birmingham RTB, Bloomfield Village RTB
No remaining CSOs. Main Branch free of CSO
impact into Detroit (Pembroke Ave).
Eliminate raw sewage, protect public health,
meet DO standard, provide for heathy biological
communities
Currently drafting NPDES permits that will
resolve last demonstration criterion, TRC
11
Redford Twp. CSO Control
One demonstration RTB constructed to correct
several CSOs
8 remaining CSOs to Upper Branch. Upper
Branch is free of CSO impact into Redford
Currently drafting NPDES permits that will
require correction of remaining CSOs by 2025
Considers the Township’s finances (medium
burden), and will continue the option to correct
CSOs regionally
12
Dearborn Heights CSO Control
One presumptive RTB constructed to correct
several CSOs, with additional CSOs added
7 remaining CSOs; one to Middle Branch, 2 to
Upper Branch, 4 to Lower Branch (3 shared with
Inkster). Middle Branch is free of CSO impact
into Dearborn Heights
Currently drafting NPDES permits that will
require correction of remaining CSOs from
2020-25
Considers the City’s finances (medium burden),
and will continue the option to correct regionally 13
Dearborn CSO Control
3 treatment/storage shafts and one storage shaft
constructed, and some separation projects
completed to address several outfalls
8 remaining CSOs; 5 to Lower Branch, 3 to Main
Branch
Recently issued NPDES permit will require
correction of remaining CSOs from 2020-25
(high burden).
Projects will be a combination of treatment
shafts, and sewer separations
14
Inkster CSO Control
2 demonstration RTBs constructed to correct
several CSOs
7 remaining CSOs; all to Lower Branch (3
shared with Dearborn Heights). Lower Branch is
free of CSO impact into Inkster
Currently drafting NPDES permits that will
require correction of remaining CSOs. Schedule
being discussed.
Considers the City’s finances (high burden)
15
Detroit WWTP and CSO Control
The current Detroit WWTP permit was
effective on May 1, 2013
Largest single site WWTP in the US
Treats dry weather flow and significant wet
weather flow through secondary treatment up to
930 million gallons per day (MGD)
Treats wet weather flow through primary
treatment up to 1700 MGD
16
3 Key Issues Addressed in
Permit
Sustained compliance with permit requirements
Reductions in authorized total phosphorus loads
to help address Lake Erie algae
Adaptive Management CSO Control program;
includes Green Infrastructure, considers Detroit
residents’ finances
17
Issue 1: Sustained Compliance
Periods of non-compliance over the last 35
years.
Was under Federal Court Order, until 2013.
Under an administrative consent order
(ACO) with the DEQ for violations from
2009-2011.
Permit specifies a “Facility Improvement
Program”
21
Facility Improvement Program
Includes ACO conditions that control the
solids inventories at the WWTP
Requires construction of new solids
dewatering equipment by 2016
Requires a Long-term Solids Disposal
Plan
Requires Asset Management to address
operation and maintenance issues
22
Adjustment of Effluent Limits
based on good O&M Monitoring periods at wet weather outfalls
changed to more quickly reflect good WWTP
operation and maintenance
Effluent limits at wet weather outfalls adjusted to
require well operated WWTP
Pollutant Previous Limit
(30 discharge
days)
Final Limit
(monthly average)
TSS 100 mg/l 70 mg/l
CBOD5 100 mg/l 40 mg/l
Total
Phosphorus
2.5 mg/l 1.5 mg/l
23
Michigan actions to address
Phosphorus into Lake Erie
Controlled WWTP discharges to Great Lakes and tributaries to 1.0 mg/l or less
Instituted statewide ban on phosphates in laundry detergent, dishwasher detergent and residential lawn fertilizer
Permitted all Concentrated Animal Feeding Operations (CAFOs) which includes comprehensive nutrient management plans
Encourages voluntary Michigan Agriculture Environmental Assurance Program (MAEAP) certifications for farms
Actively required comprehensive Sanitary Sewer Overflow and Combined Sewer Overflow correction programs for over 2 decades
25
Detroit WWTP – TP load sources
2011 % Total 2012 % Total
Secondary Treated 756590 70 751110 94
Primary Treated (WWTP/CSO facilities) 275780 26 48250 6
Untreated CSO 42090 4 2240 0
Total 1074460 100 801600 100
26
Detroit Total Phosphorus Loads
Secondary treated outfall 049B
to Detroit River – 80% of P load
Wet weather
outfalls
050A
049A
27
Reduction in Permitted
Phosphorus Levels Beginning 2015
WWTP secondary treated outfall reduced from 1.0
mg/l to 0.7 mg/l as a monthly average
Growing season average of 0.6 mg/l (from April –
September)
WWTP currently meeting 0.2 – 0.4 mg/l as monthly
averages
Based on levels the current WWTP can
achieve optimizing existing facilities
28
Michigan actions to address
Phosphorus into Lake Erie
Participant with Ohio, Indiana, Ontario
under the Great Lakes Water Quality
Agreement
Chaired by EPA and Environment Canada
Evaluate causes of Lake Erie algae
• Make recommendations
30
Issue 3: Adaptive CSO Control
Program
Municipalities must either: eliminate the CSO or
provide adequate treatment to meet all water quality standards at
times of discharge
Detroit’s collection system consists of basically
all combined sewers. Detroit’s Long-term Plan
(1996) as updated in 2001, 2008, and 2010, calls
for providing adequate treatment
Different water quality priorities for Rouge and
Detroit Rivers
31
Significant Progress to Date
This permit builds on the City’s progress in
correcting CSOs over the last 20 years, spent
~$1.2 billion
Detroit’s Long-term Control Program principles
Additional treatment capacity at the WWTP (1700
MGD), and disinfection of all flow
Construction of key Retention Treatment Basins
(RTBs) and Screening/Disinfection Facilities at key
outfalls; 6 RTBs, 3 S/D Facilities to date
Use of in-system storage
32
Significant Progress to Date – Additional
WWTP Capacity
Added more primary clarification, additional
influent pumping, to provide primary treatment
during wet weather events
Brings around 11 billion gallons per year to
WWTP of what was untreated discharges from
CSOs
Core CSO control program to be completed in
2019 with the disinfection of all wet weather
excess flow at the WWTP.
All flow disinfected to protect public health.
95% of annual wet weather flow treated 33
Significant Progress to Date – Key RTBs
and In-system storage
Completion of 4 RTBs, and one
Screening/Disinfection facility on Rouge River
Completion of 2 RTBs and 2
Screening/Disinfection facilities on the Detroit
River
6 in-system storage gates on Rouge River
outfalls, and 13 in-system storage dams in large
sewers
34
CSO Correction Progress – completion of core
program in 2019
0
5
10
15
20
25
1993 2019
Untreated CSO (BGY)
36
Adaptive Management Program
Completion of core program mean achieving a
very high level of CSO control
Remaining CSOs (55) 17 CSOs remain to the Rouge River
38 CSOs to the Detroit River
An adaptive management approach for these
will: Use lessons learned from previous CSO projects and better
discharge data
Consider the financial capability of DWSD and City residents
Consider reductions in stormwater flows by using an expanded
Green Infrastructure (GI) program
38
Green Infrastructure (GI)
Fits within the opportunities provided in the
Detroit Future City report
Areas of Green Infrastructure
Upper Rouge Area
Near Eastside Area
Develop a required level of stormwater control
for new and redevelopment by 4/1/17
39
GI - Upper Rouge Area (implementation)
Requires spending $50
million over 20 years
Spending consistent
with GI Plan, once
approved
Targeted reduction of
stormwater of 2.8 MG
by 2017
Detroit Future City Report 40
More Details – Rouge River CSOs
Rouge CSOs: Implement Green Infrastructure,
evaluate accurate discharge volumes and
frequencies from the 17 remaining CSOs.
Submit revise LTCP by 1/1/17
In 2022, and for each 5 year permit cycle,
propose gray projects to be completed in that
permit term.
Goal is to have all “high priority” CSOs corrected
by 2037.
High priority outfalls are: 059, 060, 061, 062,
063, 069, 074 (7 of the 17) 41
GI - Near Eastside (planning)
Removes gray CSO
projects from previous
permit
Allows for planning of GI
potential in an area that
has a relatively high
amount of vacant land
Requires a revised CSO
correction plan
Detroit Future City Report 42
More Details – Detroit River CSOs
Submit a revise engineering report for the near-
eastside area, 7 CSOs, by 4/1/17
In 2022, and for each 5 year permit cycle,
propose gray projects to be completed in that
permit term.
Goal is to have all “high priority” CSOs corrected
by 2037.
High priority outfalls are: 016, 019, 021, 022,
025, 026, 031, 038, 040, 044 (10 of the 38)
43
Summary of CSO Correction Progress
Significant progress in both Rouge and Detroit
Rivers over 2 decades; CSO volume reduced
sharply, several stream miles now no longer see
untreated CSO, improved water quality
More work needs to be done
Remaining suburban CSOs (23) will be
corrected by 2020-2025
Remaining City of Detroit high priority CSOs (17)
will be corrected by 2027-2037, with
consideration of an adaptive management
approach 44
Questions
Discussion
Comments
Contact: Phil Argiroff, P.E., Permits Section
517-290-3039
45