Reducing CSOs in the Big Apple
NYC’s Green and Gray Approach
2017 Wet Weather Partnership Workshop
Indianapolis, Indiana
May 4, 2017
Peter J. Young, PE, Vice President – Hazen and Sawyer
Keith Mahoney, PE, Director – NYCDEP
Kevin Clarke, PE, Portfolio Manager – NYCDEP
New York City
Wastewater
Infrastructure
DEP Provides Wastewater Services to NYC
 1.3 billion gallons of
wastewater treated
each day
 14 wastewater
treatment plants
 95 pumping stations
 7,500 miles of sewer
pipes
 Over 495 combined
sewer overflow
(CSO) discharges
Major Historical Timeline for Wastewater Infrastructure
OMB = Office of Management and Budget
Historical Investment and CSO Reduction Over Time
CSO Capture:
Current = 80%1
Future Estimate = 82%2
Note: Dashed lines reflect estimated future cost and CSO volume
reduction associated with implementation of the Long Term Control
Plans, which are currently under development. Future CSO control
will be a combination of storage and disinfection projects, with the
exact volume to be developed during the LTCP process.
1) April 2015 CSO Annual Best Management Practices (BMP) Report
2) 2030 LTCP Baseline Scenario for Grey & Green Infrastructure Estimate
Fecal Bacteria (Summer Geometric Means)
2014
1985
Fecal Coliform Bacteria:
< 100 cfu/100 mL
100 – 200
201 – 2,000
>2,000
Data from Harbor Survey Program.
Dissolved Oxygen (Summer Average for Bottom Waters)
1985
Dissolved Oxygen:
2014
≥ 5 mg/L
4.0 – 4.9
3.0 – 3.9
< 3.0
Data from Harbor Survey Program.
Capital Expenditures
NYC Income Levels and Poverty Rates
Median
Household
Income (MHI)
% of Residents
Living Below Federal
Poverty Level
United States
$53,675
15.5%
NYC
$52,996
20.9%
Bronx
$33,712
31.6%
Brooklyn
$47,966
23.4%
Manhattan
$76,089
17.6%
Queens
$57,241
15.2%
Staten Island
$71,121
14.5%
Source: U.S. Census Bureau 2014 ACS 1-Year Estimates.
 While NYC MHI is comparable to national
average, cost of living and housing burden
for NYC residents is generally much higher
 ~21% of NYC population (>1.7 million people)
lives below the federal poverty level
 ~19% of elderly population lives in poverty
Average Wastewater Bill Compared to HH Income
INCOME BRACKET
% of
Households
Less than $20,000
22%
$20,000 to $39,999
18%
$40,000 to $59,999
14%
$60,000 to $74,999
9%
$75,000 to $99,999
11%
$100,000 to $199,999
18%
$200,000 or more
8%
•
Currently ~27% of households (HH) pay 2% of income or more on wastewater/sewer bill
•
Estimating modest future rate and income increases (based on costs in the CIP and
historic Consumer Price Index data, respectively), this could increase to 40% in 2025
Avg. Wastewater Bill Compared to HH Income
Average
Wastewater
Bill/MHI
% of Household (HH) estimated to
be paying more than 2% of HH
income on Wastewater Services*
2016
1%
27%
2025
1.5%
40%
*Source: USEPA “Combined Sewer Overflows: Guidance for Financial Capability Assessment and Schedule Development” (1997)
Long Term Control Plan
(LTCP)
2012 CSO Consent Order
 Builds upon success of 2005
CSO Consent Order
• Over 120 Consent Order
milestones previously achieved
• Recommended plans from 11
Waterbody Watershed Facility
Plans are incorporated
• Projects about 90% of the NYC
waterbodies will attain existing
standards
LTCP Submittal Dates
CSO Watershed
LTCP Status
Alley Creek
APPROVED
Westchester Creek
Submitted
Hutchinson River
APPROVED
Flushing Creek
APPROVED
Bronx River
APPROVED
Gowanus Canal
APPROVED
Coney Island
Submitted
Flushing Bay
APPROVED
Jamaica Tributaries & Bay
Due June 2017
Newtown Creek
Due June 2017
Citywide
Due December 2018
DEP’s Financial Commitment to CSO Reduction
DEP is currently in the midst of an unprecedented period of investment to improve
water quality in New York Harbor, including $4.2B of existing CSO commitments.
Over $2B have been incurred to date.
Financial
Commitment
NYC’s CSO Program
Waterbody Watershed Facility Plans
and other CSO Projects
$2.7 Billion
Green Infrastructure Program
$1.5 Billion
Approved LTCPs Additional Spending*
$1.6 Billion
TOTAL
$5.8 Billion
*Additional Spending associated with approved LTCPs to date, further spending to be determined.
Rainfall Selection for Model Updates
Evaluated a comprehensive range of rainfall data:
 Historical data range:
42 years from 1969 to 2010
 Only four representative rainfall
gauges with continuous data within
this time frame: Central Park,
LGA, JFK, and EWR
 Selected 2008 JFK rainfall as
the most representative of
average annual rainfall across all
four gauges over the 42-year
period
Model Calibration & Updates
 Receiving Water Quality Model calibrated with Harbor Survey and LTCP sampling data
 Landside InfoWorks Model calibrated with LTCP flow and sampling data
 Future wastewater flows based on 2040 population projections
 InfoWorks based on revised impervious areas
 Screening of alternatives based on 1-yr data (JFK 2008 “Typical Year Rainfall”)
 Selected Plan Model runs based on 10-yr data (2001 to 2011) to address elevated
rainfall amount due to climate change
5-Year
Moving Average
LTCP Typical Year Rainfall
(JFK 2008 – 46.3
inches)
Standard for WWFP
(JFK 1988 – 40.6
2002-2011
10-Year
Water Quality
Period for
Selected Plan
inches)
CSO Mitigation Toolbox
INCREASING COMPLEXITY
Source Control
Additional Green Infrastructure
High Level Sewer Separation (HLSS)
INCREASING COST
System
Optimization
Fixed Weir
Parallel
Interceptor / Sewer
CSO
Relocation
Gravity Flow Tipping
to Other
Watersheds
Pumping Station
Modification
Water Quality /
Ecological
Enhancement
Floatables
Control
Dredging
Outfall
Disinfection
Retention Treatment Basin (RTB)
Treatment
Satellite:
Centralized:
Storage
Bending Weirs
Control Gates
Pump Station
Expansion
Flow Tipping with
Conduit / Tunnel and Pumping
Dissolved Oxygen
Improvement
Flushing Tunnel
High Rate
Clarification (HRC)
WWTP Expansion
In-System
Shaft
Tank
Tunnel
Alley Creek LTCP
Recommended Plan: Disinfect at the Existing 5 MG CSO Retention Facility during Recreational
Season (May 1st – Oct 31st)
Approved March 7, 2017
 Benefits:
 Reduce bacteria load to creek
 Avoid structural modifications to
existing tank
 Challenges:
 Control of residual chlorine
 Total Capital Cost / Annual O&M:
$7.6 Million / $250,000
Hutchinson River LTCP
Recommended Plan: Divert flow to Outfall HP-024 Extension
Provide Floatables Control
Disinfect 50 MGD in Recreational Season (May 1st thru Oct. 31st)
Approved March 7, 2017
 Benefits:
 Reduces bacteria load to river from
seasonal disinfection
 Provides floatables control
 Avoid construction of costly retention tank
 Challenges:
 Solids deposition in outfall
 Permitting of new outfall
 Total Capital Cost / Annual O&M:
$90 M / $1.25 M
Flushing Creek LTCP
Recommended Plan: Recreational Season Disinfection at Tank, DC 5, and Regulator TI-09
Provide Floatables Control at DC 3 and Regulator TI-09
Approved March 7, 2017
Benefits
Challenges
Construction
O&M Cost
Outfall TI-010
Outfall TI-011
• Provides disinfection
of tank bypass flows
• Provides
disinfection of CSO
discharge
• Disinfection
equipment can be
installed at existing
site
• Potential residual
chlorine issues
• Maximizes use of
existing
infrastructure
TI-010
• Potential residual
chlorine issues
$2 Million
$5 Million
$350,000 / Year
$300,000 / Year
TI-011
Bronx River LTCP
Recommended Plan: Hydraulic Relief (HP-007 & HP-009)
Floatables Control (HP-011)
HP-007
Approved March 7, 2017
Outfall HP-007
Benefits
Challenges
Construction
O&M Cost
• CSO volume
reduction
Outfall HP-009
• CSO volume
reduction
Outfall HP-011
• CSO volume
reduction
• Provides floatables
control
• Need to maintain
hydraulic neutrality
• Proximity to
parkland/shoreline
• Need to maintain
hydraulic neutrality
HP-009
$111 Million
$53,000 per Year
HP-011
Flushing Bay LTCP
Recommended Plan: 25 MG CSO Storage Tunnel
Approved March 7, 2017
Conceptual layout
only – final site
selection to be
performed under
the Facility Plan
Phase
 Total Capital Cost:
$670 M (Ingraham’s Site) or $829 M (Luyster Creek Site)
Green
Infrastructure
24
Green Infrastructure Program Timeline
2010 – NYC Green Infrastructure Plan
Laid framework to use green infrastructure
to manage 1” (2.5 cm)
of stormwater runoff from 10% of
impervious surfaces in combined sewer
areas by 2030.
2012 – Amended Consent Order
DEP and NYS Department of Environmental
Conservation (DEC) signed an historic
agreement to incorporate a green and grey
adaptive management approach into the CSO
program.
Benefits of Green vs Grey Investments
26
GI Application Rates and Milestone Schedule
DEP has committed to spend $1.5 billion in green infrastructure projects through 2030.
10%
Overall Goal: To
manage 1” of
stormwater
runoff from 10%
of impervious
surfaces in
combined sewer
areas by 2030
9%
8%
Initial 1.5%
7%
Additional 2.5%
6%
Additional 3.0%
Final 3%
5%
4%
3%
2%
1%
0%
2010
2015
2020
2025
2030
NYC Green Infrastructure Program
City Sidewalks
City Streets
Grant Program for
Private Property Owners
Public Property Retrofits
Right of Way Bioswales
Priority Areas and Area-wide Approach
The Area-wide Approach allows OGI to:
• Focus resources on selected CSO tributary
areas (Priority Areas)
• Saturate these CSO tributary areas with as
much GI as practical
• Achieve efficiencies through standard
designs, specifications and procedures
Newtown Creek, NCB-015 Area-wide Contract
Public Property Retrofits
Schoolyard Retrofits
Before
After
Green Infrastructure Grant Program
DEP provides funding for the design and construction of “green infrastructure” or
stormwater management practices that detain or retain stormwater runoff from
impervious surfaces such as parking lots, rooftops and internal walkways.
Brooklyn Navy Yard:
Rooftop Farm
Queens College:
Rain Garden/Pavers
Bishop Loughlin:
Green Roof
Lenox Hill House:
Green Roof
NYRP:
Rain Garden/Pavers
Osborne Association:
Blue/Green Roof
LTCP Process and Public Involvement
LTCP Due
Existing
Information
Review
Data
Collection &
Analysis
Modeling
Alternatives
Development
& Evaluation
LTCP
Alternatives
Meeting
Kickoff
Meeting
ONGOING PUBLIC / STAKEHOLDER INPUT
Typical timeline for this process ranges from 12 to 24 months, depending on
the water quality and complexity of the waterbody/watershed.
DEC Review
Final Plan
Review
Meeting
Ongoing LTCP Public Participation Program
GOAL
Raise awareness, foster understanding,
and encourage input on LTCP development
 Activities:




Annual citywide public meetings rotating across boroughs
Local public meetings in each watershed and existing forums
Meeting with key stakeholders and organizations
Briefings with elected officials and their staff
 Communication Tools:
 Program Website
 Social Media
 Advisories & Notifications