Consolidated SPDES Renewals
In January 2001, the New York State Department of Environmental Conservation ("Department") submitted A Total Maximum Daily Load Analysis to Achieve Water Quality Standards for Dissolved Oxygen in Long Island Sound (hereafter the "LIS TMDL") to the U.S. Environmental Protection Agency.
Table 6 of the LIS TMDL identifies the sum of the New York and Connecticut Waste Load Allocations ("WLAs") from each of 11 management zones. Table 7 of the LIS TMDL contains equivalency factors that identify the relative impact of nitrogen from each zone on dissolved oxygen ("DO") conditions in Long Island Sound. Compliance with the LIS TMDL can be achieved through meeting the WLAs or through new allocations resulting in equal or greater water quality improvements, as defined by the Table 7 equivalency factors. The equivalency factors comprise river delivery factors (the amount of nitrogen discharged to a river segment that makes it the mouth of the river) and Long Island Sound transport efficiencies (the relative impact of nitrogen discharged from a management zone on the hypoxic hotspots). In other words, allocations among facility-specific WLAs can be modified without resubmitting a revised LIS TMDL as long as the new allocations resulted in equal or greater water quality improvements, as determined by the use of the exchange ratios identified in Table 7 of the LIS TMDL document.
The Table 7 transport efficiencies were established from predictions of the "LIS 3.0" water quality model developed in the 1990s. A new model, called the Systemwide Eutrophication Model ("SWEM") has subsequently been developed. The Department recognized early on that SWEM had certain advantages over LIS 3.0 and that the SWEM should be used in the future, once accepted. See Department Response to Public Comments on the LIS TMDL, Modeling Tools on pg 10-11 and Recent/Future Monitoring on pg 24 (January 2001), http://www.dec.state.ny.us/website/dow/responseliss.pdf. In fact, the LIS TMDL cites the application of SWEM as one of the elements to a planned revision of the LIS TMDL. See LIS TMDL, Reassessment on pg 48 and Table 14. SWEM contains a number of technical improvements over LIS 3.0 and has since been reviewed and approved by the Long Island Sound Study for application to Long Island Sound planning and management.
In light of its subsequent approval by the Long Island Sound Study and after consultation with and without objection from Connecticut DEP, the Department hereby proposes a limited amendment to the LIS TMDL to incorporate the insights from SWEM predictions of the relationship between the DO response to nitrogen discharges from zone 8 (the upper East River Management Zone) and zone 9 (the lower East River Management Zone). This limited technical amendment would support the New York City Department of Environmental Protection's ("New York City DEP") development of a long-term nitrogen control program to attain its WLAs for zone 8 and zone 9 discharges, without compromising water quality. The technical amendment would formalize the use of SWEM ratios in meeting the allocations to those zones in advance of a more comprehensive revision of the LIS TMDL. The Department is soliciting public comment on the proposed amendment before submitting it to the EPA for review and approval.
SWEM predicts a greater overall DO response from achieving the zone 8 and zone 9 WLAs than LIS 3.0. SWEM also predicts that the ratio of the transport efficiencies (the relative impact of nitrogen discharged from a management zone on the hypoxic hotspots) between zone 8 and zone 9 is 4:1, compared to the LIS 3.0 transport ratio of 2:1. Therefore, the Department proposes to modify the LIS TMDL Table 7 transport efficiencies for zone 8 and zone 9 to a 4:1 ratio from a 2:1 ratio. New York City DEP would comply with the LIS TMDL through meeting the WLAs or through new allocations using the updates to the Table 7 equivalency factors. This revision to the equivalency factors would only apply to reallocations between zone 8 and zone 9. Because SWEM predicts a greater overall DO response from achieving the zone 8 and zone 9 WLAs than LIS 3.0, this change places no additional burden on discharges from other zones to achieve water quality standards. The timeframe for using this amendment based on a combination of SWEM and LIS 3.0 ratios would be until the anticipated full SWEM technical update (and other technical updates) are incorporated into a complete LIS TMDL revision.
Public comment on the proposed amendment will be accepted for 30 days, through April 7, 2006. Comments should be submitted in writing to Philip O’Brien of Division of Water, 625 Broadway, Albany, NY 12233-3502, or by email at email@example.com.
New York City (Staten Island) County - The New York City Department of Environmental Protection, as lead agency, has determined that the proposed Port Richmond Throttling Facility, will not have a significant adverse environmental impact. As part of the Outer Harbor CSO Facilities Planning Project, NYCDEP proposes to install a throttling facility in the 96-inch East Interceptor conveyance line that delivers combined sewage to the Port Richmond Water Pollution Control Plant (WPCP) on the Staten Island. The throttling facility will maximize wet weather flows to the WPCP, resulting in reductions in combined sewer overflow (CSO) discharges, and reduce flow velocities into the WPCP, improving headworks screening efficiency during wet weather events. The throttling facility is to be constructed under Richmond Terrace approximately 250 feet east of the Port Richmond WPCP forebay, and the access vault will be approximately 50 feet east of the intersection of Richmond Terrace and Taylor Street. The access vault and chamber for the proposed facility will be approximately 12 ft x 15 ft x 9 ft deep and located beneath Richmond Terrace.
The construction of a throttling facility is the most effective and efficient way to maximize wet weather flows to the WPCP, and to control and reduce flow velocities into the WPCP. Controlling flow velocities into the WPCP would then improve headworks screening efficiency during wet weather events. This throttling facility addresses one of the recommended improvements in the DEP's original Outer Harbor CSO Facility Plan, submitted in December 1994, which included recommendations for regulator improvements (Phase I), new throttling facilities to maximize the wet weather flows to the WPCPs (Phase II), and in-line storage to increase CSO capture (Phase III). These phases are being undertaken separately and are not interdependent facilities. The overall plan is expected to result in the capture of 83% of CSO volume in the New York City waterways. The throttling facility is also a required improvement under the CSO Order on Consent #CO2-20000107-8 between NYCDEP and New York State Department of Environmental Conservation (NYSDEC). The project is located beneath Richmond Terrace near the intersection with Taylor Street, Staten Island.
Contact: Amy Ma, New York City Department of Environmental Protection, Bureau of Environmental Planning and Assessment, 59-17 Junction Blvd, 11th Floor, Flushing, New York 11373, phone: (718) 595-6658, fax: (718) 595-4479, email: firstname.lastname@example.org.
New York City (Queens) County - The NYC Department of Environmental Protection, as lead agency, has determined that the proposed Tallman Island Ti-2/Ti-3 Water Pollution Control Plant Upgrade will not have a significant adverse environmental impact. The action involves two contracts: Contract TI-2: Emergency Main Sewage (EMS) Pumping System Modification and Replacement, and Contract TI-3: Plant Upgrade Program (PUP). The PUP would provide for Biological Nutrient Removal (BNR) by improving the aeration system. The PUP also includes the replacement of the aged main sewage pumps, blowers and drive engines with electric motors. The proposed action was developed to ensure continued compliance with wastewater permit limitations, maintain a safe working environment for the future, and meet the recently mandated citywide nitrogen removal program. The project is located at 127-01 Powell Cover Road at the western edge of Powell’s Cove in the College Point section of Queens, New York. All of the proposed action upgrades to the Tallman Island WPCP would be within the existing boundaries of the facility.
Contact: Julie Stein, NYC Department of Environmental Protection, 59-17 Junction Boulevard, 11th floor, Flushing, NY 11373, phone: (718) 594-4397, fax: (718) 595-4479, email: email@example.com.