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New York, City of (SPDES) - 4th Interim Decision, January 28, 1994

4th Interim Decision, January 28, 1994

50 Wolf Road
Albany, New York 12233-1550

In the Matter of the Application of The NEW YORK CITY DEPARTMENT OF ENVIRONMENTAL PROTECTION for Renewals of the State Pollutant Discharge Elimination System ("SPDES") Permits for New York City's 14 Wastewater Treatment Plants.


January 28, 1994


This Interim Decision addresses the proposed permit conditions for control of nitrogen loadings into the receiving waters of New York City's 14 sewage treatment plants. The proposed permit conditions were negotiated and agreed to by a consensus of the parties in the captioned proceeding.

As recognized in my first Interim Decision (January 31, 1991) in this matter, it is undisputed that the City's sewage treatment plants significantly contribute nitrogen loadings that cause hypoxia, or low levels of dissolved oxygen. Those plants that discharge into the Upper East River contribute to hypoxic conditions in the western narrows of Long Island Sound. Another sensitive water body is Jamaica Bay, which receives the discharge from four other plants. These hypoxic events, which usually occur in late summer, have many adverse effects, often including direct kills of fish and shellfish. My previous Interim Decision required that this issue be addressed in this proceeding to appropriately modify the City's SPDES permits to include a schedule of compliance to reduce nitrogen loadings and, in turn, the frequency of hypoxic conditions, stemming, in part, from the City's sewage treatment plant discharges.

After reviewing the proposed permit conditions for nitrogen removal, I concur with the recommendation of Administrative Law Judge Andrew S. Pearlstein in his attached Interim Hearing Report to approve their incorporation into the permits. Nitrogen control is a widespread and technically difficult problem. The proposed permit conditions approach it in the best way possible -- with a comprehensive, progressive, flexible and multi-faceted program that will be effective for the foreseeable future. I am pleased that the parties were able to negotiate an agreement on this issue that is designed to bring the City into compliance on the dissolved oxygen standard within the shortest reasonable time, as required by 6 NYCRR 754.3.

The permit conditions set aggregate effluent limits for nitrogen discharges for the two groups of four plants discharging into the Upper East River and Jamaica Bay, respectively. Before those limits take effect in 1996 and 1997, the City must make operational and process changes to maximize nitrogen removal in the existing plant units, and also conduct extensive pilot work to test new processes and technologies. The City and Department will then jointly determine the most appropriate new systems to implement to meet specified nitrogen reduction goals.

In the longer term, the City will also prepare a Nitrogen Control Feasibility Plan that will comprehensively analyze additional methods to meet much greater levels of nitrogen reduction for future discharges. These include approaching the problem from the demand side, with water conservation measures. Water conservation can ultimately increase nitrogen removal by reserving plant capacity for more effective performance by such technologies as biological nutrient removal systems.

I am satisfied that the proposed nitrogen removal permit conditions contain appropriate procedural mechanisms and enough milestone dates to ensure that they will be successfully executed. The conditions include detailed requirements for monitoring, record-keeping, reporting and consulting with the Department Staff. A reopener clause envisions the potential for permit modification upon the release of the Long Island Sound Study. The Technical Advisory Committee created by a side agreement will provide an additional check on the City's progress in meeting the permit's nitrogen reduction goals.

By this Decision, I approve the proposed permit conditions for nitrogen discharge control for New York City's sewage treatment plants. I direct that they be incorporated into the permits of the City's fourteen plants as soon as possible in the appropriate form for each plant as indicated in the appendices to the attached Interim Hearing Report and that they take effect immediately.

IN WITNESS WHEREOF, the Department of Environmental Conservation has caused this Fourth Interim Decision to be signed and issued and has filed the same in its office in the County of Albany, New York this 28th day of January, 1994.



In the Matter of the Application of the New York City Department of Environmental Protection for Renewals of the State Pollutant Discharge Elimination System ("SPDES") Permits for New York City's 14 Publicly Owned Sewage Treatment Plants.


DEC Case No. 0026131

Summary of Proceedings

This proceeding concerns modifications to the State Pollutant Discharge Elimination System ("SPDES") permits for New York City's 14 publicly owned wastewater treatment plants (the "plants"). The Region 2 Staff of the New York State Department of Environmental Conservation issued the City's 14 renewal SPDES permits on September 27, 1988. In a decision dated April 17, 1989, the Supreme Court of the State of New York, County of Queens (Interstate Sanitation Commission v. Jorling, et al, Index No. 16492/88, Justice Dunkin), granted the plaintiffs' petitions compelling the Department to hold an adjudicatory hearing after permit issuance, pursuant to 6 NYCRR 757.2, for possible modification of the permits.

New York State's SPDES program is governed by the Environmental Conservation Law ("ECL") Article 17 and Title 6 of the Official Compilation of Codes, Rules and Regulations of the State of New York ("6 NYCRR") Parts 750-757. New York State has been delegated authority to administer its SPDES program by the Unites States Environmental Protection Agency ("EPA") pursuant to the Federal Water Pollution Control Act (33 U.S.C. 1251 et seq, the "Clean Water Act" or "CWA"). The State's SPDES program must be consistent with the applicable provisions of the CWA and the national "NPDES" program, and with the implementing federal regulations applicable to municipal sewage treatment plants.

In this interim report, no attempt will be made to describe all prior proceedings held in this matter. For the complete context of these rulings, the reader is referred to the following rulings and decisions: ALJ's Rulings on Issues for Adjudication, April 20, 1990; Commissioner's Interim Decision, January 31, 1991; the Commissioner's Second Interim Decision (with attached ALJ's Interim Hearing Report), July 16, 1991; the ALJ's Supplemental Rulings dated January 27, 1993; and the Commissioner's Third Interim Decision dated June 1, 1993.

The parties to this proceeding are the City, the Department Staff, and the following intervenors: the Interstate Sanitation Commission ("ISC"); the Environmental Defense Fund ("EDF"); the Natural Resources Defense Council ("NRDC"); the Sierra Club; the Hudson River Fishermens Association ("HRFA"); the New York Coastal Fishermens Association; and the Connecticut Coastal Fishermens Association. The EPA, while not a party to the proceeding, has participated actively in its role as the overseer of the State's administration of its delegated SPDES program. A distribution list is attached at the end of this report.

This proceeding has followed a course in which each major area of issues concerning discrete provisions in the permits is addressed in turn. If and when a resolution is reached on any issue, the agreed upon conditions can then be incorporated into the permits without awaiting resolution of other issues remaining in dispute. This has already occurred with respect to the issues of toxic effluent standards and pretreatment requirements, and the long-term reduction of combined sewer overflows. An issue reserved for hearing, scheduled to begin in February or March of this year, is whether the City should be required to implement an enhanced street-sweeping program as an interim floatables control measure. Each of these issues was addressed in detail in the above cited rulings and interim decisions, which also dealt with the objections of some parties to portions of the initial negotiated agreements. Major issues which remain unresolved include whole effluent toxicity, flow measurement, and plant capacity problems.

This report addresses another major issue on which all parties have now reached a negotiated agreement: nitrogen control requirements for plants discharging into Long Island Sound and Jamaica Bay.

Summary of Nitrogen Control Permit Conditions

Excessive loadings of nutrients, primarily nitrogen, are the major cause of hypoxia, or low levels of dissolved oxygen (below 3 ppm or 3 mg/l) in the western narrows of Long Island Sound and Jamaica Bay. The applicable water quality standard in all the City's receiving waters, as well as Long Island Sound is 4 mg/l pursuant to 6 NYCRR 702.3. Hypoxic conditions in these waters usually occur in late summer and can result in severe kills of fish and shellfish. Four of the City's sewage treatment plants (Wards Island, Tallmans Island, Bowery Bay, and Hunts Point) discharge into the upper East River and significantly contribute to nutrient loadings and hypoxic conditions in western Long Island Sound. Four other plants (Jamaica, 26th Ward, Rockaway, and Coney Island) discharge nutrients into Jamaica Bay with similar hypoxic effects.

The existing permits for all of the City's 14 sewage treatment plants contain no requirements for the control of the discharge of nutrients into the receiving waters. The permits do reference the ongoing federal/state joint Long Island Sound Study and New York/New Jersey Harbor National Estuarine Program Study, both of which will ultimately produce recommendations for nutrient removal and other water quality problems in those receiving waters.

The proposed new permit conditions incorporate a comprehensive program for the progressive reduction of nutrient loadings from the eight plants that discharge into the Upper East River (from where the flow enters the western Long Island Sound) and Jamaica Bay over the next decade. A prototype permit for the Wards Island plant is attached to this report as Appendix A. The other six plants that discharge into the Hudson River, Lower East River, or New York Harbor, are subject to some of the general nitrogen reduction operational and monitoring requirements, but not to the effluent limits, pilot work, and other specific technical requirements applicable to the eight discharging into hypoxia-sensitive waters. A matrix indicating the nitrogen reduction requirements applicable to each of the City's 14 sewage treatment plants is attached as Appendix B.

The four plants discharging into the Upper East River and the four discharging into Jamaica Bay are grouped into two "bubbles" for the purpose of setting aggregate monthly nitrogen discharge limits. The aggregate maximum monthly average limits become effective January 1, 1996, and the 12-month rolling average limits become effective January 1, 1997. In the interim, the permits (1) require the City to implement process control and operational changes to maximize nitrogen removal with existing treatment processes and units.

By June 30, 1994, the City must submit to the Department a Nitrogen Control Action Plan (3). This plan must be implemented if the nitrogen effluent limits are exceeded by specified amounts. The Nitrogen Control Action Plan will be designed to include short-term measures for achieving the effluent limits, such as sewer connection or extension restrictions, water conservation, trading with other point sources, and separate treatment of plant side streams and sludge centrate loads.

In the longer term, the permits (5 and 6) require the City to engage in specified pilot work in two phases. Phase I pilot work is to be completed and demonstrated by June 30, 1996, and Phase II by December 31, 1997. Phase I requires installation of chemical enhanced thickening systems at two plants; fixed media tests; and testing recycle equipment for biological nitrogen reduction ("BNR"). In Phase II, the City will test other equipment and methods for nitrogen removal, including sludge centrate treatment; a thickening centrifuge; package BNR units; and will conduct additional research in conjunction with the City University of New York. The goal of the pilot work is to determine the most practical and effective means of removing nitrogen from the plants' effluent in order to achieve aggregate nitrogen removal in specified amounts below the average monthly nitrogen effluent limits for the Upper East River and Jamaica Bay.

For the still longer term, the permits (6) require the City to prepare a Nitrogen Control Feasibility Plan by December 31, 1998. This plan will contain an engineering report that analyzes conceptual future nitrogen removal methods including retrofitting BNR units; any other methods that may achieve higher specified removal levels; cost estimates; and demand-side or water conservation strategies. The report will analyze whether water conservation programs could achieve reductions in water use that could effectively assist nitrogen removal and accommodate existing flows and projected increased flows through the City's plants.

The permits also include a reopener clause that allows the Department Staff or any interested person to initiate permit modification proceedings pursuant to 6 NYCRR Part 621. Such modifications are particularly contemplated as possible upon the completion of the Long Island Sound Study 3.0 Water Quality Model for the four plants discharging into the Upper East River, and upon completion of the "Jamaica Bay 2" follow-up to the Jamaica Bay CSO Study for the four plants discharging into that water body.

The City has also agreed, as in the settlement on toxics abatement, to establish a Technical Advisory Committee ("TAC") on nitrogen reduction. The TAC will consist of five outside experts who will consult and report to the City and Department on a regular basis at all critical junctures during implementation of the nitrogen control program, beginning this year.


The proposed nitrogen control permit conditions summarized above were derived through a lengthy and complicated process of negotiation among the parties to this proceeding. The key intervening parties on this issue were the Hudson River Fishermens Association and the Environmental Defense Fund. They, along with the City and Department Staff, deserve credit for cooperating to produce a comprehensive program that will substantially reduce nitrogen loadings into the East River, Long Island Sound, and Jamaica Bay over the next decade.

While nobody expects that hypoxia will be eliminated instantly, these permit conditions provide a feasible and multi-pronged approach that represents the best chance at this time for greatly reducing the instances of dissolved oxygen concentrations below the applicable water quality standard of 4 mg/l in Jamaica Bay, the East River and Long Island Sound. The proposal amounts to a compliance schedule designed to achieve full compliance with the dissolved oxygen standards within the shortest reasonable time, as required by 6 NYCRR 754.3. The permit conditions represent an enormous improvement over the pre-existing permits which contained no nitrogen control requirements whatsoever. I recommend that the Commissioner approve the proposed nitrogen control permit conditions and direct the Department Staff to incorporate them into the permits for the City's 14 wastewater treatment plants as soon as possible.

Andrew S. Pearlstein
Administrative Law Judge

Dated: January 28, 1994
Albany, New York

To: Distribution List Attached

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