Facilities plan
1. Background
2. Treatment
3. Alternative sites
4. Approaches
5. Evaluation
6. Optimized plan
7. Schedule
Appendices

Env info document

Clinton Street CSO abatement project facilities plan (draft) — February 2005
by Environmental Engineering Associates, LLP
for Onondaga County Department of Water Environment Protection

Appendix B. Pages 7 and 8 of ACJ Appendix B—Clinton CSO Project Description

I. Within sixty days of the entry of the Amended Consent Judgment, the County shall submit to DEC a schedule for each project listed in Appendix B, specifying dates for the performance of the following activities: (1) compliance with SEQRA, if required, (2) site acquisition, and (3) submittal of engineering reports and plans.

II. Upon approval by DEC and filing with the Court, the schedule shall be incorporated into and made an enforceable part of the Amended Consent Judgment. The dates in the schedule shall become minor milestone compliance dates within the meaning of paragraph 31 of the Amended Consent Judgment.

III. CSO Project Descriptions

Major CSO Projects

1. Midland Avenue Conveyances Project: The service area for this facility encompasses the majority of the combined sewer area on the southern end of the City of Syracuse. The pipelines and regulators will be sized on the basis of a one-year storm. Even above the one-year storm, the collection system will intercept a high percentage of the volume associated with these precipitation events.

2. Midland Avenue Regional Treatment Facility ("RTF") Project: The Midland Avenue RTF Project will be located near Oxford Street and Onondaga Creek. The proposed treatment facility will include coarse screening in front of the facilities pump station wet well. Pumps will be used to lift the flow from the 050 transmission pipelines up to the vortex device where floatables and gross solids will be removed. The flow will then proceed to the disinfection tank, where it will be disinfected with either sodium hypochlorite or another disinfectant recommended after completion of the Newell Street CSO disinfection demonstration project. All treatment and transmission processes will be sized to accommodate the one-year storm at this facility. Concentrated solids from the RTF will be discharged back into the Main Interceptor Sewer (MIS) for treatment at METRO. This facility incorporates an interconnection to the MIS to capture overflows from the MIS during intense rainfall events. The only time that the interconnection will be active is during MIS surcharging conditions, thereby ensuring that the more concentrated "first flush" of pollutants is retained within the MIS.

3. Clinton Conveyances Project: The interceptor pipelines will be designed to transmit the discharges associated with all CSO events equal to or less than the one-year storm. The length and diameter of the associated pipelines also allows the capture and storage of an appreciable percentage of all wet weather discharges. Pipelines necessary to intercept the discharge from the above-noted overflows will be constructed first and will terminate at the wet well for the RTF. A floatables entrapment device will be installed within the wet well area until such time when the remainder of the RTF is constructed. : of the floatable solids will be removed at the point of discharge rather than being captured by the Onondaga Creek boom located at the head of the Inner Harbor.

4. Clinton RTF Project - The Clinton RTF Project will abate those CSO discharges located within the downtown portion of the Onondaga Creek basin. The basis of design of the RTF will be the 90-percentile storm for the vortex device and one year storm for the disinfection facilities. The wet well and pumping capacity for the Clinton RTF, however, will be sized to accommodate the peak discharge of a one-year storm. This will provide disinfection for all flows up to a one-year storm event. The design of the Clinton RTF will allow for the expansion of the facility up to the one-year storm basis of design. Expansion of the facility for flows up to and including the one-year storm will require a second 48-foot diameter vortex.

The Clinton RTF Project will include coarse screening in front of the pump station wet well. Pumps will be used to lift the flow from the CSO transmission pipelines up to the vortex device where floatables and gross solids will be removed. The flow will then proceed to the disinfection tank, where it will be disinfected with either sodium hypochlorite or another disinfectant recommended after completion of the Newell Street CSO disinfection demonstration project. Concentrated solids from the RTF will be discharged back into the MIS for treatment at METRO. This facility, like that of Midland, will incorporate an interconnection to the MIS that will capture overflows from the MIS during intense rainfall events. The only time that the interconnection will be active is during MIS surcharging conditions, thereby ensuring that the more concentrated "first flush" of pollutants is retained within the MIS.

5. Franklin Floatables Control Facility and Conveyances Project: The Franklin FCF will be located near the intersection of Routes 690 and 81. At this location, the two tributary trunk sewers associated with this facility (Burnet Avenue and Butternut Street) are only 400 feet apart. These trunks serve the northeast portion of the city. The FCF will comprise connecting pipelines and a floatables containment structure.

6. Maltbie Street Floatables Control Facility: Maltbie Street will include a floatables containment structure. Many of the floatable materials will be removed at the point of discharge rather than being captured by the Onondaga Creek floatables trap located at the head of the Inner Harbor. Pipelines will be constructed and a floatables containment structure will be incorporated into the existing pumping station superstructure.