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New York, City of (SPDES - Ward's Island) - Ruling, September 4, 1997

Ruling, September 4, 1997

STATE OF NEW YORK : DEPARTMENT OF ENVIRONMENTAL CONSERVATION

In the Matter of the Application to Renew the State Pollutant Discharge Elimination System (SPDES) Permit (1) Whole Effluent Toxicity, for New York City's 14 Water (2) Flow Measurement, and Pollution Control Plants by (3) Plant Capacity

CITY OF NEW YORK DEPARTMENT OF ENVIRONMENTAL PROTECTION (NYCDEP)
APPLICANT

(Ward's Island)

September 4, 1997

ISSUES RULING ON REMAINING ISSUES

Summary

This ruling addresses the last set of unresolved issues concerning the 1988 SPDES permits for New York City's 14 water pollution control plants (WPCPs). For the complete context of these rulings and the other issues related to these SPDES permits, the reader is referred to the following Rulings, Interim Hearing Reports, and Interim Decisions:

  1. Issues Ruling of the Administrative Law Judge, April 20, 1990;
  2. Commissioner's Interim Decision, January 31, 1991;
  3. Commissioner's Second Interim Decision (with attached ALJ's Interim Hearing Report), July 16, 1991;
  4. Supplemental Rulings of the ALJ, January 27, 1993;
  5. Commissioner's Third Interim Decision, June 1, 1993;
  6. Commissioner's Fourth Interim Decision (with attached ALJ's Interim Hearing Report), January 28, 1994;
  7. Issues Rulings Concerning Floatables Abatement, October 25, 1995;
  8. Issues Ruling Concerning Proposed Modification dated March 1996, July 17, 1996; and
  9. Commissioner's Fifth Interim Decision, October 7, 1996.

The issues proposed by Hudson River Fishermen's Association concerning the whole effluent toxicity study are not substantive and significant. However, the effluent limit for total residual chlorine will be determined within the context of this proceeding. With respect to flow measurement and plant capacity, the Interstate Sanitation Commission (ISC) has raised a substantive and significant issue about how the NYC Department of Environmental Protection (DEP) calculates dry weather flows for the WPCPs. In addition, the ruling directs the Department Staff to prepare a draft permit condition that will require DEP to install double flow monitoring systems at all the WPCPs. Finally, the ruling provides a schedule for filing appeals with the Commissioner.

Proceedings

This proceeding concerns modifications to the State Pollutant Discharge Elimination System (SPDES) permits for New York City's 14 Water Pollution Control Plants (WPCP). Pursuant to 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, the Region 2 Staff of the NYS Department of Environmental Conservation (the Department Staff) renewed DEP's 14 SPDES permits on September 27, 1988 without a hearing. In a decision dated April 17, 1989, however, the NYS Supreme Court, Queens County, directed the Department to hold a hearing, as provided by 757.2, for possible modification of the September 1988 permits (Interstate Sanitation Commissioner v. Jorling, et al., Index No. 16492/88, Justice Dunkin).

All but three issues certified by the Commissioner remain unresolved. They are: (1) whole effluent toxicity, (2) flow measurement, and (3) plant capacity.

In January 1997, Ms. Houdek, counsel for the City's Department of Environmental Protection (DEP), explained that DEP's consultant, Lawler, Matusky & Skelly Engineers, LLP (Pearl River, NY) had undertaken an extensive whole effluent toxicity (WET) study, as required by the terms of the 1988 SPDES permits. With a cover letter dated January 24, 1997, Ms. Houdek distributed copies of the two comprehensive reports prepared by DEP's consultant. The reports are entitled, Attainment Evaluation of the Acute Whole Effluent Toxicity Criterion, May 1994, and Attainment Evaluation of the Chronic Whole Effluent Toxicity Criterion, May 1996.

On February 24, 1997, the Parties and I attended a technical conference where DEP's consultant presented an overview of the results from the WET studies and answered questions. Subsequently, DEP distributed additional information with a cover letter dated March 17, 1997.

Thereafter, I asked the intervening Parties to submit statements explaining whether adjudication of the whole effluent toxicity issue was still necessary, and if so, precisely what should be adjudicated at the hearing. I requested similar statements from the Parties about the flow measurement and plant capacity issues.

By letter dated April 9, 1997, Mr. Sullivan from the Pace Environmental Litigation Clinic, Inc., on behalf of the Hudson River Fishermen's Association, proposed issues about the whole effluent toxicity study. Also considered below are correspondence from Mr. Sullivan dated April 14, 1997 and May 9, 1997. In a letter dated April 11, 1997, Ms. Millett, General Counsel, Interstate Sanitation Commission, proposed issues about flow measurement and plant capacity.

By letter dated May 16, 1997, Ms. Houdek filed DEP's response, and asserted that any remaining questions about whole effluent toxicity, flow measurement, and plant capacity were no longer substantive and significant issues for adjudication. By letter dated May 20, 1997, Mr. Nehila, Assistant Regional Attorney, filed the Department Staff's response, and likewise contended there were no longer any issues for adjudication.

Discussion

I. Whole Effluent Toxicity (WET)

The concept of whole effluent toxicity relates to how effectively water pollution control plants (WPCPs) treat the wastewater that flows through them. The principle is simply that treated wastewater should not have a toxic effect on the organisms in the receiving waters. If laboratory studies show that the treated effluent is toxic, then additional treatment at the WPCP may be necessary to limit the discharge of particular substances, like metals or chlorides, or to change a characteristic of the discharge, such as the pH or temperature.

The September 1988 SPDES permits required a whole effluent toxicity study of DEP's 14 water pollution control plants [Part I, Page 5 of 33 of the SPDES permit for the Ward's Island WPCP]. Subsequently, DEP, in consultation with the Department Staff, developed a protocol based on the guidance provided in the DEC Division of Water Technical and Operational Guidance Series (TOGS) 1.3.2 entitled, Toxicity Testing in the SPDES Permit Program, revised May 1990, and the New York State Manual for Toxicity Testing of Industrial and Municipal Effluents, February 1985. For certain aspects of the toxicity study, DEP and the Department Staff also relied on the technical guidance provided in documents prepared by the US Environmental Protection Agency (EPA).

After the Court determined that an administrative public hearing was necessary, the Parties stipulated that whole effluent toxicity would be an issue for adjudication. No where in the file of this matter, however, can I find any further refinement of the issue. Consequently, the issue concerning whole effluent toxicity has become rather obscure at this point in the proceeding.

When the adjudicatory hearing began, DEP had not yet retained its engineering consultant to perform the study required by the 1988 SPDES permits. Although the Department Staff had approved the protocol for the toxicity study, there seems to have been no input from the intervening Parties. Now, after reviewing the reports distributed in January 1997, the Hudson River Fishermen's Association (the Fishermen's Association) contends there are substantive and significant issues about the protocol used for the WET study.

Although I can rule on the merits of the claims made by the Fishermen's Association, the WET issue might have been resolved earlier if the intervening Parties had an opportunity to comment during the development of the WET protocol. If necessary, the protocol could have been the subject of the adjudication. Now that the WET study is complete, Unless otherwise modified, however, the SPDES permits still require DEP to continue to collect samples on a quarterly basis and test them. we are now in the position of closing the barn door after the horse has run away.

Nevertheless, DEP, its engineering consultant, the Department Staff, and the intervening Parties have spent considerable effort and resources on this issue. Therefore, I am characterizing the WET issue as follows for the purpose of this ruling. Since the SPDES permits currently in effect require continued sampling and testing, the issue shall be whether the protocol should be modified in the manner asserted by the Fishermen's Association for future WET studies.

Summary of the Results from the WET Study

For a five year period, the SPDES permits required acute and chronic toxicity studies on effluent samples collected every quarter (i.e., every three months) from DEP's 14 water pollution control plants. DEP's consultant performed toxicity tests on both unchlorinated and chlorinated effluent samples. Attached to this ruling as Appendix A is a summary of the WET protocol and an explanation of the various terms used in the reports prepared by Lawler, Matusky & Skelly Engineers, LLP.

The results from the whole effluent toxicity study show that acute toxicity is related to the degree of treatment provided by the water pollution control plants. Unchlorinated whole effluent from the plants with only primary treatment was toxic. During the study period, some WPCPs were upgraded to include secondary treatment (e.g., North River), and the toxic effect of the effluent was substantially reduced or eliminated. Throughout the study, unchlorinated whole effluent from plants with secondary treatment was generally not toxic. Chlorinated effluent was toxic. DEP's consultant is in the process of doing a follow-up study to determine the in-stream die-off rate for chlorine.

Chronic toxicity is also related to the degree of treatment. Chronic toxicity was exhibited in undiluted effluent samples from all WPCPs. All WPCPs, however, complied with the chronic toxicity criteria (CCC).

Proposed Modifications to Future WET Studies

The Fishermen's Association contended that six topics in the protocol should be changed or refined in the future. They are: (1) the lack of a plant test species, (2) the drifting organism method, (3) the toxic effect of chlorinated effluent, (4) the source of the dilution water, (5) the criterion continuous concentration (CCC), and (6) quarterly testing. Each topic is addressed separately below.

1. Plant Species

The Parties dispute the number of different test species that should be included in the toxicity study. Without providing any references, the Fishermen's Association asserted that both federal and state guidance recommend using three test species: two different animal organisms, an invertebrate and a vertebrate, as well as a plant species. The Fishermen's Association wants DEP to expand the scope of its toxicity studies to include a suitable marine plant species. The Department Staff and DEP argued, however, that using invertebrate and vertebrate animal species provide sufficient sensitivity.

Discussion and ruling: The organisms used in DEP's toxicity study are the sheepshead minnow and the mysid shrimp. The minnow is a vertebrate, and the shrimp is an invertebrate. There is no dispute about the suitability of the sheepshead minnow and the mysid shrimp as test organisms.

Contrary to the assertions made by the Fishermen's Association, the Department's guidance recommends using two animal species: an invertebrate and a vertebrate (TOGS 1.3.2, p. 4). Therefore, using the sheepshead minnow and the mysid shrimp as test organisms is consistent with the Department's guidance.

Although the Parties offered no particular reference for my review and consideration, all Parties agreed that the EPA guidance recommends using a plant species in addition to animal species for WET studies concerning discharges to fresh water. The Parties also agreed that the EPA guidance does not identify any suitable plant species for WET studies when the receiving waters are marine or estuarine.

Though recommended by the EPA, there is no federal statutory or regulatory provision that requires DEP to include a plant species as a test organism in the toxicity study when the receiving waters are marine or estuarine. Absent such a requirement as well as any guidance, the request by the Fishermen's Association that DEP develop a methodology using a marine plant species as a test organism for future WET studies is not persuasive. Therefore, I deny the request.

2. Drifting Organism Method

For the acute phase of the WET studies, the acute mixing zone (AMZ) is the area around the outfall or diffuser where the effluent initially mixes with the receiving waters. When treatment plant effluents are discharged to streams, organisms generally flow through AMZ once, and continue downstream. Due to the tidal nature of the receiving waters for DEP's 14 WPCPs, however, organisms may pass through the AMZ as the tide ebbs and floods. To determine compliance with the criteria maximum concentration (CMC), DEP's consultant developed the drift organism method to evaluate the potential toxic effects on the test organisms caused by the extended time that they spend in the AMZ due to tidal fluctuations.

Initially, the Fishermen's Association was concerned that DEP's consultant had underestimated the path of maximum exposure in the AMZ. This in turn would underestimate the results for the median lethal concentration (LC50), and the acute toxic unit values (TUa). The acute toxic units for each effluent sample were compared to the standard of .3 TUa to determine compliance with the criteria maximum concentration [See Appendix A]. However, by letter dated May 9, 1997, Mark Sullivan, on behalf of the Fishermen's Association, stated that this concern had been resolved.

3. Chlorinated Effluent

The toxicity study required by the 1988 SPDES permits required DEP to include analyses on chlorinated and unchlorinated effluent samples. Because chlorine dissipates readily, its effects are more applicable to the acute phase of the toxicity studies. To test the effects of chlorine, DEP's consultant, therefore, added chlorine to the effluent samples in the lab, rather than collect chlorinated effluent samples from the receiving waters.

The results of the study show that the chlorinated effluent is toxic. Consequently, DEP's consultant undertook a study to determine the in-stream die-off rate for chlorine. DEP expected that the study would have been completed in June 1997. Depending on the results of the study, all Parties agreed that an effluent limit for total residual chlorine may have to be developed, and then be incorporated into the SPDES permits.

There is a dispute, however, about how and when the effluent limit for residual chlorine should be incorporated into the SPDES permits. The Fishermen's Association wants the record of this proceeding to remain open until the results of the chlorine die-off study are available. The Department Staff argued that the permit modification procedures provided in 6 NYCRR 621.14, and the guidance outlined in the Department's Environmental Benefit Permit Strategy should be used to modify the SPDES permits, if necessary.

Ruling: As explained further below, ISC has raised a substantive and significant issue about the method used to calculate dry weather flows. Since the record of this proceeding will remain open to consider that issue, an effluent limit for total residual chlorine can be determined within the context of this proceeding. Therefore, DEP shall distribute copies of the report concerning the in-stream die-off rate for chlorine as soon as it becomes available.

4. Dilution Water

DEP's consultant used filtered tap water adjusted to a salinity range of 25 - 28 ppt as dilution water. The Fishermen's Association contended, however, that this practice is inconsistent with the guidance provided by both the EPA and the Department. The Fishermen's Association asserted that the dilution water should be collected upstream from the discharge points to determine whether there are any cumulative effects from contaminants already in the receiving waters.

Given the tidal nature of the receiving waters, the Department Staff argued that it would be impractical to find an "upstream" source of dilution water. The Fishermen's Association contended, however, that the extensive dye and dilution studies done by DEP's consultant could be used to identify an "upstream" source.

When the purpose of the study is to estimate the chronic toxicity of the effluent, DEP argued that EPA guidance prefers the use of dilution water prepared from deionized tap water with either reagent grade chemicals or sea salts added (i.e., synthetic dilution water). Citing additional EPA guidance, DEP argued that the effects from chronic toxicity are not additive.

Discussion and ruling: At issue is the objective of the chronic toxicity study. According to EPA guidance, if the objective of the study is to estimate the chronic toxicity of the effluent, a synthetic dilution water prepared from deionized tap water with either reagent grade chemicals or sea salts added can be used [7.1.1.1, EPA Short-Term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Water to Marine and Estuarine Organisms, July 1994, Second Edition]. If the purpose of the study, however, is to determine the additive or mitigating effects of the discharge on already contaminated receiving water, the source of the dilution water should be the receiving water collected outside the influence of the outfall [7.1.1.3, supra].

The intent of the toxicity testing required by the SPDES permits [Toxicity Testing Program, Part I, Page 5 of 33 of the SPDES permit for the Ward's Island WPCP] is to ensure that the effluents discharged are not toxic to aquatic life [TOGS 1.3.2]. With respect to chronic toxicity, the EPA's Technical Support Document for Water Quality-based Toxics Control, March 1991, reports that the ambient toxicity of a mixture of pollutants is not equal to the sum of each toxic agent (1.6.2). Accordingly, the EPA concluded that chronic toxicity should not be considered additive. Given the purpose of the WET study required by the SPDES permits and the EPA's conclusion, it is, therefore, appropriate to use synthetic dilution water as outlined in 7.1.1.1 (supra) for any future toxicity study.

5. Criteria Continuous Concentration (CCC)

Chronic toxicity relates to the adverse effects on organisms caused by long term (i.e., 7 days) exposure to toxic substances. The EPA defines the criteria continuous concentration (CCC) as the highest in-stream concentration of a toxic substance or effluent to which organisms can be exposed indefinitely without causing any unacceptable effects. By definition, the CCC equals one chronic toxic unit (1 TUc).

With respect to compliance with the CCC, the dispute among the Parties focuses on calculating the chronic toxicity unit (TUc). The Fishermen's Association argued that DEP should rely on the EPA guidance in calculating the TUc. DEP and the Staff argued, however, that the Department's guidance DEC Division of Water TOGS 1.3.2, Toxicity Testing in the SPDES Permit Program, revised May 1990, and New York State Manual for Toxicity Testing of Industrial and Municipal Effluents, February 1985. is equally acceptable. See Appendix A for a more detailed explanation about the meaning of the terms discussed below.

Discussion and ruling: According to the test protocol used by DEP's consultant, attainment of the criteria continuous concentration (CCC) would be achieved if the in-stream waste concentration (IWC) is less than 1 TUc for at least half of the quarterly sampling events in one year, and any single toxicity test is not considered severe. As explained above, the results of the chronic toxicity study show that all 14 water pollution control plants attained compliance with the chronic toxicity criterion.

According to the EPA guidance, the TUc is equal to 100 times the inverse of the No-Observable-Effect-Concentration (NOEC). The Department Staff argued, however, that determining actual NOEC values is difficult unless the test protocol has incorporated an expanded dilution series from what is typically used. Since DEP's study involved 14 water pollution control plants, and data was collected every quarter for five years, the Staff argued that anything other than the typical dilution series would have been impractical.

Based on the Department's guidance, the TUc is equal to 100 times the inverse of the critical value (ChV). The ChV is the geometric mean of the NOEC and the Lowest-Observable-Effect-Concentration (LOEC) [TOGS 1.3.2]. Since the LOEC is also determined by comparing effluent dilutions, the Staff argued that determining actual LOEC values would also be difficult without an expanded dilution series.

The Fishermen's Association, however, asserted that using the chronic value to calculate the TUc inappropriately underestimates the in-stream waste concentration (IWC). To support its position, the Fishermen's Association cited data from the Jamaica Bay WPCP. In the third quarter of 1990, the NOEC for the Jamaica Bay facility was 6.25 and the LOEC was 12.5. Using the Department's guidance, the chronic value is 8.8, and the TUc is 11.4. Since the design factor for the Jamaica Bay WPCP is 12.8, the IWC is 0.9, which is less than the CCC of one standard TUc. The Fishermen's Association pointed out, however, that if only the NOEC is used, the TUc would be 16, and the IWC would be 1.25, which is greater than the CCC of one standard TUc.

According to the Department Staff, an NOEC of 6.25 for the Jamaica Bay plant occurred only twice during the study. The first time was the third quarter of 1990, and second time was the first quarter of 1995. For all other test samples from the Jamaica Bay facility, the Staff stated that the IWC would have been less than one standard TUc regardless of whether the NOEC or the chronic value was used to calculate the TUc.

Ruling: The example provided by the Fishermen's Association is not persuasive, and provides no basis for relying on the EPA's guidance for calculating the TUc over the Department's guidance. Consequently, there is no need to adjust the method for calculating the TUc for determining compliance with the CCC in any future toxicity study.

6. Quarterly Testing

The SPDES permit condition setting forth the requirements for toxicity testing specified quarterly testing (i.e., four times per year). However, by letter dated February 16, 1997, Joseph DiMura, P.E., Interim Director for the Bureau of Wastewater Facilities Design, DEC Division of Water, stated that the Department expects to reduce the frequency of routine testing and focus on more intensive testing at the water pollution control plants that have had limited cases of toxicity.

The Fishermen's Association wants the quarterly testing to remain in place. DEP stated that it would continue to abide by the current permit condition which requires quarterly testing, unless the Department modifies the sampling schedule. The Department stated that if permit modification were appropriate, the procedures outlined in 6 NYCRR 621.14, and the guidance provided in the Environmental Benefit Permit Strategy would be used.

Ruling: Mr. DiMura's February 16, 1997 letter does not modify the 1988 SPDES permits. Since the permit modification procedures provided in 621.14, and the Environmental Benefit Permit Strategy would be used before the sampling schedule is modified, members of the public, including the Fishermen's Association, would have an opportunity to review and comment on any proposed changes. Consequently, no further action concerning the testing schedule is necessary within the context of this proceeding.

Based on the discussion above, the protocol for any future toxicity studies should not be modified. In addition, an effluent limitation for total residual chlorine will be determined within the context of this proceeding.

II. Flow Measurement and Plant Capacity

Earlier this year, there were discussions about possibly resolving the flow measurement and plant capacity issues without a hearing (Memorandum dated January 16, 1997). With respect to the flow measurement issue, DEP explained that it had developed a model for using an independent consultant to insure the accuracy of flow measurements at the North River Plant. In January 1997, ISC explained that to resolve this issue, the intervening Parties want DEP to apply the North River Plant model to the other WPCPs. As explained in its submission dated April 11, 1997, this remains ISC's position.

Concerning plant capacity, the Department Staff proposed a permit condition that would require DEP to measure the flow through each of the treatment facilities at two different points (double metering). The measurements would also include recycled flow.

In its submission dated April 11, 1997, however, ISC rejected the proposed permit condition as a way to resolve all its outstanding concerns about plant capacity. Nevertheless, the Department Staff's response dated May 20, 1997 (p. 15) explained that the Staff was going to initiate a permit modification proceeding after the conclusion of this hearing to incorporate the double metering requirement into DEP's SPDES permits.

ISC argued there are six adjudicable issues related to flow measurement and plant capacity. By letter dated April 14, 1997, the Fishermen's Association expressed its support for the issues identified by ISC. ISC's six proposed issues for adjudication are: (1) total flow vs. dry weather flow, (2) design criteria used to determine plant capacity, (3) initial and periodic flow verification and calibration by an independent outside consultant, (4) capacity assurance program, (5) pump back to the WPCPs of flow captured during wet weather, and (6) maximization of CSO flow to the WPCPs. Each topic is discussed separately below.

1. Dry Weather Flow

DEP explained that all the WPCPs, except the Oakwood Beach plant, receive both sanitary sewage (dry weather flow) and wet weather flow, which consists of sanitary sewage mixed with stormwater. For the thirteen treatment plants that receive both dry and wet weather flows, the effluent limitation in the SPDES permits for flow is expressed as dry weather flow. In addition, there is a permit condition that requires DEP to monitor total flow continuously. At the Oakwood Beach plant, the effluent limitation for flow is expressed as total flow since it only receives sanitary sewage.

ISC objects to the permit condition limiting flow to dry weather flows. The basis for ISC's objection is that DEP has allegedly not shown that the method used to calculate dry weather flow is valid and reasonable. According to ISC, the methodology is biased toward lower dry weather average values, which would erroneously suggest that the WPCPs have additional treatment capacity. ISC argued further that the calculated dry weather flow values do not represent the flow conditions under which biological oxygen demand (BOD) and total suspended solids (TSS) are measured. Consequently, ISC recommended that the SPDES permits limit flow to total flow rather than to dry weather flow. In addition, ISC wants DEP to provide additional information about how to calculate dry weather flow.

DEP provided a copy of the methodology used to calculate dry weather flow, and it is attached to this ruling as Appendix B. Citing TOGS 1.3.3 entitled, SPDES Permit Development of POTW, December 1990, DEP argued that the permit condition limiting flow to dry weather flow is consistent with the Department's guidance. According to DEP, the methodology is a conservative statistical analysis where suspected wet weather flows can be quantitatively compared to averages of dry weather flows. DEP explained that some of the suspected wet weather flow data can be included in the dry weather flow average if that data is within a specified confidence interval. Contrary to ISC's contention, DEP asserted that the methodology ensures that the average dry weather flow could only error on the high side.

The Department Staff explained that the SPDES permits require the WPCPs to be able to accept at least two times the design flow to ensure enhanced wet weather capture. The concept of dry weather flow was developed to meet this permit requirement. The Department Staff argued further that assessing dry flow, rather than total flow, is a better way to determine whether a WPCP has too much development connected to it, or whether a WPCP is receiving too much water. The Staff contended that mass loading should be based on dry weather flow, and not on total flow as claimed by ISC, because a large component of the mass loading during wet weather comes from combined sewers. As a result, the Department Staff argued that the WPCPs treat a substantial amount of the flow from combined sewers, which would bypass the treatment plants if the flow limit is based on total flow.

Discussion and ruling: ISC does not raise a substantive and significant issue for adjudication with respect to changing the flow limit from dry weather flow to total flow. The rationale for limiting flow to the dry weather flow is to enhance wet weather capture. As a result, secondary treatment for all dry weather flows is assured This assumes that the WPCP provides secondary treatment. since it would be expected that the dry weather flow for a particular treatment plant is equal to or less than the plant's design capacity. During some minor or short wet weather events, the combined dry and wet weather flows would also receive secondary treatment as long as the flow did not exceed the plant's design capacity. For large wet weather events or for extended wet weather periods, the applicable statutes and regulations recognize that treatment plants that receive combined flow (i.e., dry and wet weather flows) may not be able to meet effluent limits for BOD and suspended solids [40 CFR 133.103(a), and 6 NYCRR 751.1(a)(1)]. As a result, the operators of such plants may seek relief from these requirements [e.g., Ward's Island SPDES permit p. 3, footnote 5].

ISC, however, does raise an adjudicable issue about the method used to calculate dry weather flows. The permit limit on flow is essential to determining compliance with the terms of the SPDES permits. Such things as determining plant capacity, and maintaining adequate capacity hinge on DEP's ability to accurately calculate dry weather flows.

Further inquiry is necessary because there is conflicting expert opinion about how to calculate dry weather flows. Therefore, the issue is substantive. The issue is significant because DEP may need to adjust the method for calculating dry weather flows as a result of the adjudication. Consequently, the flow limits set forth in the SPDES permits may need to be modified, if the method for calculating dry weather flows needs to be adjusted.

In Exhibits B and C attached to ISC's letter dated April 11, 1997, ISC stated that this issue could be resolved without a hearing if DEP provided additional information about the method used to calculate dry weather flows. During the course of this proceeding, the Parties have been able to resolve much more significant and technically complex issues without a hearing. Therefore, I encourage the Parties to do the same with this comparatively minor issue.

2. Design Criteria to Determine Plant Capacity

ISC stated that New York State has adopted the Ten States Standards that set forth design guidelines for sewage treatment plants. The members include: Illinois, Indiana, Iowa, Michigan, Minnesota, Missouri, New York, Ohio, Pennsylvania, and Wisconsin. The Province of Ontario, Canada, is also a member. After reviewing the design parameters for DEP's 14 WPCPs, ISC argued that the primary settling tanks at all the treatment plants violate the design criteria for the maximum surface overflow rate specified in the Ten States Standards. According to ISC, this lack of compliance with design recommendations provides inadequate treatment that adversely effects water quality.

Discussion and ruling: ISC raises no issue for adjudication about using the Ten States Standards to determine plant capacity. By letter dated August 9, 1997, the Department Staff advised DEP that the Department would not approve any future upgrades unless the primary settling tanks are designed to meet the criteria provided in the Ten State Standards. Contrary to ISC's assertions concerning potentially adverse impacts to water quality standards, the BOD and TSS discharges from all 14 WPCPs in Fiscal Year 1996 were well below the effluent limits established in the SPDES permits.

3. Flow Verification

After issues concerning flow measurement and plant capacity were joined for adjudication, ISC compared the 1990 dry weather flows at DEP's 14 WPCPs with the flows from 1989. According to ISC, the comparison showed significant reductions in flows at some of the treatment plants. Although the reductions, in part, were the direct result from improved operations, such as the installation of new flow meters, ISC argued that some reductions in flow were unexplained. To address this concern, ISC proposed that the SPDES permits require DEP to hire an independent consultant to calibrate and verify the flow meters at each of the treatment plants on a quarterly basis.

DEP explained that each plant has a primary flow meter, as currently required. DEP also stated that secondary flow monitoring systems have been installed at all but two plants (Bowery Bay and Coney Island) to provide supplemental flow information. According to DEP, its personnel inspect flow meters daily, and calibrate them semi-annually according to established maintenance and calibration procedures. Contrary to ISC's contentions concerning unexplainable reductions in flow, DEP asserted there has been a steady downward trend in plant flows over the past five years from increased water conservation efforts.

The Department Staff verified that DEP has installed secondary flow monitoring systems at most of the treatment plants. The Staff argued that double metering would assure that flows will be accurately monitored at the WPCPs. The Department Staff also explained that at the conclusion of this hearing, they would rely on the procedures outlined in 6 NYCRR 621.14 and the Environmental Benefit Permit Strategy to modify the SPDES permits by adding a condition for double metering.

Discussion and ruling: DEP's ability to accurately measure flow is essential to calculating reliable dry weather flow values. However, ISC has provided no legal or technical basis for its request that DEP hire an independent consultant to calibrate and verify the flow meters at each of the treatment plants on a quarterly basis. I find that the secondary flow monitoring systems being installed at DEP's WPCPs adequately address concerns about flow verification. Furthermore, ISC offered nothing to show that flow monitoring equipment should be recalibrated quarterly rather than semi-annually. ISC's concern about the significant reduction in flow at the North River WPCP is addressed separately below, and is not sufficient, by itself, to raise a substantive and significant issue for adjudication with respect to DEP's 14 WPCPs.

The Department Staff's proposal to modify the SPDES permits by requiring double metering after the conclusion of this hearing would be grossly inefficient. DEP has essentially complied with the double metering requirement except at the Bowery Bay and Coney Island WPCPs. Therefore, DEP would not be expected to object to such a permit condition. Furthermore, ISC's refusal to settle all proposed issues related to flow measurement and plant capacity by accepting a double metering condition does not prevent the Department from incorporating this condition into the SPDES permits now.

As soon as possible, the Department Staff shall prepare a draft permit condition concerning double metering. The Parties will have an opportunity to review and comment on the proposed draft permit during the public comment period [6 NYCRR 753 (Notice and Public Participation)]. The comment period could coincide with the hearing on the method for calculating dry weather flow.

4. Capacity Assurance

ISC wants a permit condition that requires DEP to file a program with the Department that would prevent the facilities from becoming overloaded whenever the flow at the treatment plants reaches or exceeds 90% of the permitted flow capacity. ISC argued that this permit condition is necessary because seven of the 14 WPCPs were at, or over, their design capacities when the Department issued the 1988 SPDES permits. ISC further proposed that when flows reach 95% of capacity, that the Department issue a notice of moratorium on new connections, and then impose a moratorium if flows reach 100% of capacity.

DEP explained that the City has already implemented many of the points outlined in ISC's Exhibit C concerning capacity assurance. For example, the City has implemented a water conservation program. Also, universal water metering is required by law (NYC Admin. Code 4-334, as amended by Local Law 35 of 1985). Furthermore, the SPDES permits require DEP to initiate and maintain a continuous inflow/infiltration (I/I) assessment and correction program when the average dry weather influent flow reaches 95% of capacity. DEP argued that any moratoria imposed by the Department should be consistent with the guidance provided by TOGS 1.4.7, Sewer Moratorium on New Connections to POTW's, March 14, 1988.

The Department Staff argued that the permit condition requiring continuous I/I assessment and correction program when influent flows reach 95% of capacity, as well as the Department's enforcement authority are sufficient to ensure that the WPCPs will not exceed their capacities. According to the Staff, influent flows have dropped during the 1990s as a direct result of I/I assessments.

Discussion and ruling: ISC has provided no legal or technical basis for its request that an evaluation of plant capacity should begin when influent flows reach 90%. Consequently, there is no issue for adjudication concerning capacity assurance.

In rejecting ISC's proposed issue, I also rely on the following. First, the City of New York has already implemented many of the programs outlined in ISC's Exhibit C concerning capacity assurance with respect to water conservation, metering, and I/I assessments. In addition, I defer to the Department Staff's judgment that initiating continuous I/I assessments and correction programs at 95% capacity would adequately assure that treatment plant capacities will not be exceeded. Finally, ECL Article 17 and Article 71, Title 19 authorize the Department to impose moratoria if plant capacities are exceeded, and TOGS 1.4.7 provides guidance about how the Department would implement this public policy.

5. Pump Back of Wet Weather Flows

Under the terms of the Track 1 Program outlined in the Combined Sewer Outfalls (CSO)/Floatables Consent Order, DEP would construct off-line storage/treatment facilities to collect solids and water from the combined sewer system during wet weather events. Subsequently, the collected stormwater would be pumped back to a WPCP for treatment.

ISC wants a permit condition that controls how collected wet weather flows are pumped back to the WPCPs. According to ISC, the pump back periods could be considered wet weather events for regulatory purposes. During these "artificial" wet weather events, ISC argued that less than secondary treatment might be legally acceptable. ISC is concerned that extending wet weather events with pump backs would adversely impact water quality in the long run.

Discussion and ruling: DEP and the Department Staff argued that ISC's proposed issue concerning pump back of wet weather flows is premature because the terms of the Track 1 Program are just being implemented. According to DEP and the Staff, this issue should be deferred until after off-line storage/treatment facilities are built.

I agree. Therefore, ISC's proposed issue concerning pumping back of wet weather flows will not be considered further in this proceeding.

6. Maximization of CSO flow to WPCPs

The 1988 SPDES permits require those WPCPs that serve combined sewers to accept at least two times the design flow during wet weather events. As explained above, the purpose of this permit condition is to provide enhanced wet weather capture with the understanding that some treatment is better than no treatment. ISC generally agrees with the principle of enhanced wet weather capture. ISC argued, however, that this permit condition may not be appropriate for every WPCP. Instead, ISC recommended that each WPCP should be evaluated individually to determine whether accepting twice the design flow at a particular plant actually protects the quality of the receiving waters.

DEP and the Department Staff argued that ISC's position is contrary to federal and state guidance concerning CSO abatement [EPA Combined Sewer Overflows: Guidance for Nine Minimum Controls, May 1995; DEC TOGS 1.6.3, Combined Sewer Overflow (CSO) Control Strategy, October 1, 1993]. These Parties cited surveys which show that the quality of the receiving waters around New York City has improved since the WPCPs started to accept twice the design capacity during wet weather events.

Discussion and ruling: ISC's position about maximizing CSO flows to the WPCPs is not contrary to the federal and state guidance identified above. Rather, ISC's contention is that requiring all WPCPs to accept twice the design capacity during wet weather events might not be the best way to abate the water quality problems associated with combined sewer overflows.

Nevertheless, ISC offered nothing to support its contention. Without any offers of proof, I dismiss ISC's proposed issue concerning the maximization of CSO flows to the WPCPs as speculative. Consequently, there is no substantive issue for adjudication [Matter of Concerned Citizens Against Crossgates v. Flack, 89 AD2d 759 (3rd Dep't, 1982) aff'd, 58 NY2d 919 (1983)].

III. North River Water Pollution Control Plant

The North River Water Pollution Control Plant is located on the eastern bank of the Hudson River in Manhattan. The WPCP discharges an annual average flow of about 182 million gallons per day (MGD). In April 1991, the treatment plant started to provide secondary treatment.

In April 1994, there was a 26 MGD drop in flow at the North River plant. Staff from the DEC and ISC inspected the facility to determine the causes. For reasons not explained in the record, local elected officials, community groups, and business people are also concerned about the quality of service provided by the plant.

Attached as Exhibit C to ISC's April 7, 1997 submission is a letter dated February 7, 1996 from Howard Golub, P.E., Acting Director and Acting Chief Engineer, Interstate Sanitation Commission, to Richard Newman, P.E., Water Program Director, NYSDEC Region 2. In his letter, Mr. Golub asked the Department to reconsider its position that the drop in flow and other concerns associated with the North River WPCP should be addressed in this adjudicatory hearing. Instead, Mr. Golub recommended that the Department undertake a separate investigation of the North River plant.

In its submission dated May 16, 1997, DEP stated that it supported ISC's recom-mendation concerning the North River plant (footnote 3, p. 10). The Staff's submission dated May 20, 1997, however, is silent about how the Department wants to review operations at the North River WPCP.

Details about the April 1994 drop in flow, and the local community's concerns about the service provided by the North River WPCP are not part of the record of this hearing. These circumstances appear to be unique to the North River plant. In addition, nothing has been offered to showing how the circumstances identified above concerning the North River plant relate to the issues concerning whole effluent toxicity, wastewater flow, or plant capacity. Therefore, this proceeding will not address the drop in flow and the other concerns unique to the North River WPCP.

APPEALS

Pursuant to 6 NYCRR 624.8(d), the Parties may appeal these rulings on issues. The Commissioner must receive any appeals by October 6, 1997. Appeals shall be double-spaced and not longer than 25 pages. Replies are authorized, and the Commissioner must receive them by October 29, 1997. Replies shall be double-spaced and not longer than 15 pages. The Commissioner will not accept service of appeals and replies by fax.

Send one copy of any appeal and reply to the Commissioner, NYS Department of Environmental Conservation, Room 608, 50 Wolf Road, Albany, New York 12233-1010. Also, send one copy of any appeal and reply to everyone named on the attached Service List dated June 5, 1997. Finally, send one copy of any appeal and reply to the Administrative Law Judge. Parties who use word processing equipment to prepare the appeal and reply must also submit a copy of their appeal and reply to the ALJ in electronic form on a 3.5 computer disk formatted in either WordPerfect 5.1 or ASCII.

Appeals and replies must be distributed to everyone at the same time and in the same manner.

Any request for an adjustment to the appeal schedule must be made to the

Chief Administrative Law Judge,
NYS Department of Environmental Conservation,
Office of Hearings and Mediation Services,
50 Wolf Road, Albany, New York 12233-1550
Telephone: 518-457-3468,
FAX: 518-485-7714.

/s/
Daniel P. O'Connell
Administrative Law Judge
Dated: Albany, New York
September 4, 1997

To: Attached Service List dated June 5, 1997

Attachments:
Appendix A, Summary of WET Study Protocol.
Appendix B, Calculation of Average Dry Weather Flow.

APPENDIX A

Summary of the Whole Effluent Toxicity (WET) Study

For a five year period, the 1988 SPDES permits required toxicity studies on effluent samples collected every quarter (i.e., every three months) from the 14 water pollution control plants (WPCPs) operated by the NYC Department of Environmental Protection (DEP). As explained further below, the toxicity study consisted of acute and chronic phases. In addition, the studies included toxicity tests on both unchlorinated and chlorinated effluent samples.

DEP retained Lawler, Matusky & Skelly Engineers, LLP to perform the WET study. DEP's consultant prepared two comprehensive reports entitled, Attainment Evaluation of the Acute Whole Effluent Toxicity Criterion, May 1994, and Attainment Evaluation of the Chronic Whole Effluent Toxicity Criterion, May 1996.

The results from the whole effluent toxicity study show that acute toxicity is related to the degree of treatment provided by the water pollution control plants. Unchlorinated whole effluent from the plants with only primary treatment was toxic. During the study period, some WPCPs were upgraded to include secondary treatment (e.g., North River), and the toxic effect of the effluent was substantially reduced or eliminated. For the acute phase of the study, unchlorinated whole effluent from plants with secondary treatment was generally not toxic. Chlorinated effluent, however, was toxic.

Chronic toxicity is also related to the degree of treatment. Chronic toxicity was exhibited in undiluted effluent samples from all WPCPs. All WPCPs, however, complied with the chronic toxicity criteria (CCC).

The first step of the WET study was to conduct dye studies at each of the 14 WPCPs to determine the areas in the receiving wasters around the treatment plant outfalls from which to collect the effluent samples. The dye studies were used to map two areas in the receiving waters near the outfalls or diffusers. The first area was the acute mixing zone (AMZ). The AMZ is an area close to the outfall or diffuser. Samples taken from the edge of the AMZ were compared to the criteria maximum concentration (CMC) to determine whether the samples were acutely toxic.

The second area was the chronic mixing zone (CMZ). Generally, the area of the CMZ is larger than the AMZ. Samples taken from the edge of the CMZ were compared to the criteria continuous concentration (CCC) to determine whether the samples were chronically toxic. As a result of the dye studies, effluent samples were collected from the AMZ for the acute phase, and from the CMZ for chronic phase of the WET study.

In the laboratory, the effluent samples were divided in half. For each half, a portion of the sample remained undiluted and therefore contained 100% of the sample. The remainder of the sample was diluted by dividing it in half and then adding synthetic dilution water Synthetic dilution water is discussed in the ruling on pp 6-7. to make up the original volume. Repeating the process created a dilution series of 50%, 25%, 12.5%, 6.25% of the original concentration (i.e., 100%) of the sample. In other words, the 50% dilution was half effluent sample and half synthetic dilution water. The 25% sample was effluent sample and three quarters synthetic dilution water, etc. A final a tube containing only synthetic dilution water was added to the dilution series. Since the last tube contained no (or 0%) of the sample, it served as a control for the synthetic dilution water.

Each half of the sample was diluted in the same manner. Different test organism were then added to each of the two sets of dilutions. The two animal test species are: (1) sheepshead minnow [Cyprinodon variegatus], a vertebrate, and (2) mysid shrimp [Mysidopsis bahia], an invertebrate. The purpose of the WET study was to determine whether these organisms could live in the various dilutions, and if not, in which dilutions did the test organisms die.

For the acute phase of the toxicity study, the dilution series were examined after 48 hours, and the median lethal concentrations (LC50) were determined. The LC50 is the dilution (i.e., 100%, 50%, etc.) in which 50% of the test organisms die after 48 hours. Then, the LC50 values for each effluent sample were converted into acute toxic units (TUa). The TUa is equal to 100 times the inverse of the LC50. The calculated TUa values were then compared to the criteria maximum concentration (CMC).

The EPA defines the CMC as the highest in-stream concentration of a toxic substance or effluent to which organisms can be exposed for a brief period of time (i.e., 48 hours) without causing mortality. For the acute phase of the toxicity study, the standard TUa (which is defined as the criteria maximum concentration) was .3 TUa. Therefore, dilutions were not considered acutely toxic if the calculated TUa for any dilution sample was less than .3 TUa.

For the chronic phase of the WET study, the dilution series were examined after 7 days to determine whether the test organisms survived, and whether they grew. Since the reproductive cycle for the mysid is less that seven days, observations were also made about whether the mysid reproduced. For each effluent sample, two result values were obtained for the chronic phase of the toxicity study. They were: (1) the No-Observable-Effect-Concentration (NOEC), and (2) the Lowest-Observable-Effect-Concentration (LOEC).

The NOEC is the highest concentration to which organisms can be exposed in a chronic test that causes no observable adverse effect on the test organisms. In other words, the NOEC is the highest effluent concentration where the results are not statistically different from the control (i.e., the 0% dilution). The LOEC is the lowest effluent concentration to which organisms can be exposed in a chronic test that causes adverse effects on the test organisms.

Based on the Department's guidance, the chronic toxicity unit (TUc) is equal to 100 times the inverse of the critical value (ChV). The ChV is the geometric mean The geometric mean is the square root of the product of two values. To calculate the chronic value, one would first multiply the NOEC value and the LOEC value together, and then take the square root of that product. of the NOEC and the LOEC. The calculated TUc values are then compared to the criteria continuous concentration (CCC).

The EPA defines the CCC as the highest in-stream concentration of a toxic substance or effluent to which organisms can be exposed indefinitely without causing any unacceptable effects. For the purposes of the chronic phase of the toxicity study, the standard TUc (which is defined as the criteria continuous concentration) was 1 TUc.

To determine compliance with the criterion continuous concentration (CCC), the in-stream waste concentration (IWC) for effluent samples taken from each water pollution control plant was compared to the CCC. To comply with the CCC, the IWC must be less than the standard 1 TUc, as explained above. For each effluent sample collected, the IWC is the TUc divided by the design dilution factor for each WPCP.

Each treatment plant's design dilution factor is unique because it depends on the characteristics of the receiving water body. For example, three treatment plants discharge to Jamaica Bay, which is an enclosed shallow bay with a relatively high detention time. Six treatment plants discharge to the East River, which is a tidal river. Tidal rivers are generally characterized by limited widths and swift-moving currents that promote rapid mixing and high dilution. Finally, the Oakwood Beach treatment plant discharges to the Atlantic Ocean. There are no disputes associated with determining the dilution factors for each of DEP's 14 WPCPs.

For example, the in-stream waste concentration (IWC) for the Jamaica Bay WPCP was calculated as follows. The Jamaica Bay plant has a design dilution factor of 12.8. In the third quarter of 1990, the NOEC for the facility was 6.25 and the LOEC was 12.5. Using the Department's guidance, the chronic value is 8.8, which is the mean square root of 6.25 and 12.5 ( 6.25 x 12.5 = 8.8). The TUc is 11.4 (100/8.8 = 11.4), and the IWC is 0.9 (11.4/12.8 = 0.9).

APPENDIX B

Calculation of Average Dry-Weather Flow

  1. Hourly flows are recorded daily and entered on a spreadsheet at each plant. For plants using influent flow meters which also record recycles, correction for the recycle flow rate is made.
  2. If there is rain, it is noted in the log by the watch engineer.
  3. At the end of the month, when all of the hourly flows for the month have been entered, "preliminary dry-weather hourly flows" are determined. This is done by eliminating all of the hourly flow data on the days and/or watch-shifts for the time period when rainfall was recorded. Flow data that is attributable to stormwater runoff which enters the plant after a rainfall has ended is also eliminated.
  4. A "preliminary-average dry-weather flow" is then calculated using the preliminary dry-weather hourly flows. A standard deviation of these data points is also determined.
  5. Using the information, a statistical analysis is performed. All of the hourly flows for the month (both wet and dry) are checked to determine if they fall within the 2 standard deviations of the preliminary-average dry-weather flow. This is the 95% confidence level. If an hourly "wet" flow falls outside of the confidence interval, it is estimated; the preliminary-average dry-weather flow is used to replace the data point for that hour. Conversely, if a suspected "wet" hourly flow is within the confidence interval, its value is put back into the data set. No dry data is ever thrown out, even if it exceeds the confidence interval.
  6. Final dry-weather daily and monthly averages are then calculated using the data points that were determined in Step 5. The final numbers are then reported.
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