1. Onondaga County CSO Program:
Gray-Green Infrastructure
Harbor Brook CSO 018 Constructed
Wetlands Pilot Treatment System
Joanne M. Mahoney, County Executive
Prepared for:
Onondaga County, Syracuse, New York
Prepared by:
and
March 2011

2. 2
March 2011
Project Location
The project is located
along Harbor Brook
on County property
just south of Burnet
Park on the west side
of Syracuse near the
Skunk City
neighborhood.

3. 3
11/18/2010
Existing Site

4. 4
March 2011
Site Enhancement Ultimate Vision
▫ Wetland treatment
of CSO 018
▫ Grit and floatables
removal of CSO 018
▫ Improved water
quality in Harbor
Brook
▫ Community park
▫ Educational
resource

5. 5
March 2011
First Step to Site Enhancement
Design and
construction of a 2
acre full scale pilot
treatment wetland
system along Harbor
Brook at Combined
Sewer Overflow
(CSO) 018.

6. 6
March 2011
Conceptual Rendering
Three types of
wetlands will be
constructed for pilot
testing: Floating
Wetland Island,
Vertical Downflow,
and Surface Flow.

7. 7
March 2011
Pilot Treatment Wetlands System
Floating Wetland Island
▫ Vegetation mats
planted with diversity
of native species
▫ Mats float on water
surface with roots in
water column
▫ Provides high storage
volume without
inundating plants
▫ High habitat value
▫ Low mosquito
productivity

8. 8
March 2011
Floating Wetland Islands

9. 9
March 2011
Pilot Treatment Wetlands System
Vertical Downflow Wetland
▫ Flow is dosed and
distributed across
surface to percolate
through gravel bed
▫ Planted with robust
native species to
tolerate flooding and
draining
▫ No open water and no
mosquito productivity

10. 10
March 2011
Vertical Downflow Wetlands

11. 11
March 2011
Pilot Treatment Wetlands System
Surface Flow Wetland
▫ Most closely resembles
a natural wetland of
robust native species
▫ Vegetated shelf and
deep water zones to
redistribute and aerate
▫ Medium to high storage
volume
▫ High habitat value
▫ Low mosquito
productivity
▫ Relatively low cost

12. 12
March 2011
Surface Flow Wetland

13. 13
11/18/2010
CSO 018 Treatment Overview

14. 14
March 2011
Pilot Operations - Series Flow

15. 15
March 2011
Pilot Operations - Parallel Flow

16. 16
March 2011
Pilot Operations – Series & Parallel

17. 17
March 2011
Pilot Treatment System Benefits
• Pilot system will provide immediate water
quality improvements:
▫ Grit and floatables (onsite at-grade structure)
▫ Bacteria
▫ Nutrients (nitrogen and phosphorus)
▫ Total suspended solids and BOD5
• Recommendation from pilot will result in a final
permanent wetland treatment system
• Designed for 1-year, 2-hour storm event, but
higher flows and volumes could be accepted

18. 18
March 2011
Permits and Approvals Required
• SPDES Permit Modification for CSO 018 – NYSDEC
• Article 15 Permit Modification Protection of Waters – NYSDEC
• Section 401 Water Quality Certification – NYSDEC
• SPDES General Construction Permit – NYSDEC
• Nationwide Permit No.7 Outfall Structures – USACE
• Nationwide Permit No.43 Stormwater Mgmt. Facilities – USACE
• Coordination with NYS Natural Heritage, U.S. Fish & Wildlife
Service, and NYS Office of Parks, Recreation and Historic
Preservation
• OCDWEP – fill and compensatory storage
• City of Syracuse Site Preparation Permit (10,000 SF threshold)
• City of Syracuse Curb-cut Permit (access to grit & floatables facility)

19. 19
March 2011
Stakeholder Outreach
• City of Syracuse • Federal Agencies
▫ Dept of Engineering ▫ U.S. Army Corps of Engineers
▫ Bureau of Planning and ▫ Federal Emergency
Sustainability Management Agency
▫ Dept of Public Works ▫ USGS (gauging station)
▫ Dept of Parks and Recreation
▫ Div of Code Enforcement • Organizations and Not-for-
profit Groups
• New York State Agencies ▫ Atlantic States Legal
▫ Dept of Environmental Foundation, Inc.
Conservation ▫ Onondaga Environmental
▫ Dept of Transportation Institute
▫ Onondaga Nation
▫ Westside TNT Neighborhood

20. 20
March 2011
Stakeholder Outreach
• Organizations and Not-for- • Schedule
profit Groups, continued ▫ March 18 City/County
▫ Syracuse United Neighbors Meeting presentation
Westside Coalition ▫ April 7 meeting with Mayor
▫ Partnership for Onondaga and County Executive
Creek ▫ Correspondence and
▫ Syracuse Parks Conservancy consultation as needed
▫ Syracuse Chargers Rugby ▫ Presentation to community
Club group leaders in mid-April
▫ Catholic Charities
• Other Municipalities
▫ Town of Geddes Supervisor

21. 21
March 2011
Project Schedule
• Design and stakeholder outreach is underway
• Permit submittals and regulatory approvals are
critical for schedule
• Construction is targeted for 2011
• 2 year monitoring period
• Planning and design for final wetland treatment
system and site enhancement can begin during
monitoring period

22. 22
March 2011
Questions and Discussion