TO PROVIDE FUNDS FOR THE FIXED CHARGES AND FOR THE OPERATION AND MAINTENANCE OF THE ENTIRE SEWER SYSTEM IN THE CITY OF BUFFALO AND ALL OF THE BUFFALO SEWER AUTHORITY FACILITIES FOR THE CONVEYANCE, TREATMENT AND DISPOSAL OF SEWAGE AND STORM WATER OPERATED BY THE BUFFALO SEWER AUTHORITY.

I. SEWER RENTS FOR PREMISES SITUATED WITHIN THE LIMITS OF THE CITY OF BUFFALO

(a) $12,050,000 shall be collected from all real property in the City of Buffalo (the "City") by apportioning the said amount upon such property within the City as the same is set down on the last completed annual assessment roll of the City, except that no ad valorem sewer rent shall be assessed against real property exempt from real property taxes pursuant to subdivision one of section four hundred, sections four hundred four, four hundred six, four hundred twelve, four hundred eighteen, subdivision one section four hundred twenty, section four hundred forty-six, four hundred fifty-two, four hundred sixty-two and four hundred seventy-seven of the New York Real Property Tax Law.

(b) In the event a person, lot, parcel of land, building or premises, other than a City department, situated within the limits of the City, discharging sewage, water or other liquids into the Buffalo Sewer Authority (the "Authority") sewer system, either directly or indirectly, is a user of water supplied by the Buffalo Water Board or from any other source, and the quantity of water used is measured by a water meter acceptable to the Authority, then in each such case, the quantity of water used, as measured by said meter, shall be used to determine the sewer charge or rental, and the charge for such use shall be as follows:

1. $48.30 for 0 to 4,000 cubic feet of water used per quarter year, if the meter is read quarterly, and any water used in excess thereof shall bear a sewer charge or rental of $11.09 per thousand cubic feet ($.0111 per cubic foot).

2. $16.10 for 0 to 1,333 cubic feet of water used per month, if the meter is read monthly, and any water used in excess thereof shall bear a sewer charge or rental of $11.09 per thousand cubic feet ($.0111 per cubic foot).

Provided that the minimum charge shall be $16.10 per month if the meter is read monthly and $48.30 per quarter year if the meter is read quarterly.

II. SEWER RENTS FOR PREMISES SITUATED OUTSIDE THE LIMITS OF THE CITY OF BUFFALO

(a) An annual service charge for the privilege of connecting with the facilities of the Authority shall be due for any premises situated outside the limits of the City for each $1,000 of assessed valuation as determined on the last completed annual assessment, the same rate of $2.71239 per $1,000 of assessed valuation for 2021-2022.

(b) In the event a person, lot, parcel of land, building or premises, other than a City department, situated outside the limits of the City, discharging sewage, water or other liquids into the Authority sewer system, either directly or indirectly, is a user of water supplied by the Buffalo Water Board or from any other source, and the quantity of water used is measured by a water meter acceptable to the Authority, then in each such case, the quantity of water used, as measured by said meter, shall be used to determine the sewer charge or rental, and the charge for such use shall be as follows:

1. $48.30 for 0 to 4,000 cubic feet of water used per quarter year, if the meter is read quarterly, and any water used in excess thereof shall bear a sewer charge or rental of $11.09 per thousand cubic feet ($.0111 per cubic foot).

2. $16.10 for 0 to 1,333 cubic feet of water used per month, if the meter is read monthly, and any water used in excess thereof shall bear a sewer charge or rental of $11.09 per thousand cubic feet ($.0111 per cubic foot).

Provided that the minimum charge shall be $16.10 per month if the meter is read monthly and $48.30 per quarter year if the meter is read quarterly.

III. GENERAL PROVISIONS

(a) In the event a person, lot, parcel of land, building or premises discharging sewage, water or other liquids into the Authority sewer system, either directly or indirectly, is a user of water supplied by the Buffalo Water Board, and the quantity of water used is not measured by a water meter acceptable to the Authority, then the sewer charge or rental for all such accounts shall be in the respective amounts (expressed in dollars) set forth in Exhibit A, attached hereto and made a part hereof, as the Authority determines applicable to such person, lot, parcel of land, building or premises.

(b) In addition to all other rentals and charges provided herein, a monthly drainage connection service charge shall be due for any and all persons, lots, parcels of land, building or premises, other than a City department, that discharge sewage, water or other liquids into the Authority sewer system, either directly or indirectly, as follows:

1. A monthly charge of $6.00 shall be due for all lots, parcels, land, buildings or premises where the quantity of water used is not measured by a meter acceptable to the Authority.

2. A monthly charge in the amounts set forth below shall be due for all lots, parcels, land, building or premises where the quantity of water used is measured by a meter acceptable to the Authority in accordance with the following meter size:

(c) In the event a person, lot, parcel of land, building or premises discharging sewage, water or other liquids into the Authority sewer system, which directly or indirectly, uses water obtained from a source other than the Buffalo Water Board, and the water so obtained is not measured by a water meter acceptable to the Authority, then, in each such case, the owner, user or other interested party shall, at his own expense, furnish, install, and maintain a water meter or other water or sewage measuring device acceptable to the Authority and the quantity of water used, as measured by said meter, or as otherwise determined, shall be used to determine the sewer charge or rental and there shall be charged an amount determined as set forth in paragraphs II(a), III(a) and III(b) as the case may be.

(d) In the event a person, lot, parcel of land, building or premises discharging sewage, water or other liquids into the Authority sewer system, either directly or indirectly, uses water in excess of 4,000 cubic feet per quarter year and it can be shown to the satisfaction of the Authority, that a portion of the water as measured by the water meter does not and cannot enter the Authority sewer system, then the Authority may determine in such manner as may be found practicable the percentage of metered water entering the Authority sewer system and the quantity of water used to determine the sewer charge or rental shall be that percentage, so determined, of the quantity of water measured by the water meter, or the Authority may require or permit the installation of additional meters or measuring devices in such a manner as to determine the quantity of water or sewage actually entering the Authority sewer system, in which case the quantity of water used to determine the sewer charge or rental shall be the quantity of water actually entering the Authority sewer system and so determined.

(e) In the event a person, lot, parcel of land, building or premises discharges sewage or other wastes into the Authority sewer system which, in the opinion of the Authority, contain unduly high concentrations or any substances which add to the operating costs of the Authority facilities, then the Authority may elect to establish and collect special rates of charge, based on the quantity of these substances, which rate of charge may be established and collected in such manner as the Authority may elect and such charge shall be paid to the Authority, or it may elect to exclude such sewage or other wastes from its facilities.

(f) As a condition of a Buffalo Discharge Elimination System Permit (BPDES), a user may be required to pay an industrial waste surcharge for discharging sewage or waste exhibiting a strength of sewage or waste greater than normal domestic sewage. The Industrial Waste Surcharge Formula reflecting the Treatment Plant unit costs for treatment of Biochemical Oxygen Demand (BOD₅) Total Suspended Solids (TSS) and Total Phosphate (TPO₄) is as follows:

Surcharge = 8.34 QMGY (0.1855 (BOD₅-250) + 0.2079 (TSS-250) + 0.0203 (TPO₄-15.35))

$0.1855 Cost/lb. for treatment of BOD₅ $0.2079 Cost/lb. for treatment of TSS $0.0203 Cost/lb. for treatment of TPO₄

QMGY shall mean the annual total industrial and sanitary discharge - water retention.

BOD₅ shall mean the average concentration of BOD₅ in sewage or waste discharged to the Authority facilities.

TSS shall mean the average concentration of TSS in sewage or waste discharged to the Authority facilities.

TPO₄ shall mean the average concentration of TPO₄ in sewage or waste discharged to the Authority facilities.

Surchargeable concentrations are as follows:

BOD₅ - Over 250 mg/L; TSS - Over 250 mg/L; TPO₄ - Over 15.35 mg/L

This formula shall be applied in computing the Buffalo Industrial Waste Surcharge subsequent to July 1, 2020 and ending June 30, 2021 for all users that discharge sewage or waste exhibiting a strength of sewage or waste greater than normal domestic sewage. In addition, this formula with the above rates will be used to calculate all monthly, quarterly, semiannual, and annual accounts subsequent to July 1, 2021.

(g) Any person who violates the Sewer Regulations of the Authority or the conditions of the permits issued thereunder shall be subject to fines as specified in said regulations.

(h) Whenever sewage or other wastes result in conditions in the Authority sewer system as to cause blockage or a substantial reduction in the flow, charges for the work necessary to eliminate such blockage or reduction in flow may be made, based upon costs incurred by the Authority for labor, materials, equipment hire, insurances, and other overhead, against the owner of the property or premises that caused the discharge of such sewage or other wastes into the Authority sewer system.

(i) Where sewer facilities have been installed to serve improved and unimproved property and have been paid for in whole or in part by the Authority, a charge shall be made based on a proportionate share of the original cost, determined by the foot frontage of the parcel served, or by the area of such parcels, or by such other method the Authority determines to be equitable, as a condition to a permit for a connection to the Authority's facilities.

(j) An application and inspection fee for sewer connection permits shall be paid as follows at the time said application is filed with the Authority:

(k) An application fee of $50 per 2,500 square feet or part thereof of soil disturbance or impervious area being drained, whichever is greater, shall be paid at time of plans and/or calculations are submitted to the Authority for site stormwater management review.

(l) An application fee of $150 plus $25 for every 100 linear feet or part thereof of new sanitary sewer pipe proposed shall be paid at the time that plans and/or calculations are submitted to the authority for any facility proposing to discharge 2,500 gallons per day or more of additional sanitary and/or industrial flow than existing conditions.

(m) All persons owning or operating a pump truck or other transport vehicle and desiring to discharge wastes, directly or indirectly, into the Authority's facilities shall first secure a valid Truckers Discharge Permit after paying an annual permit fee of $120.00. In addition to said permit fee, a separate charge shall be billed based upon the verified quantity or truck capacity, and character of the waste discharged and, if applicable, the point of discharge.

The following surcharge rates are hereby charged for such wastehaulers who are located outside the City:

The above surcharge rates, along with costs incurred by the Authority when handling, testing, conveying, and administering each wastehauler, will be used to determine the cost per gallon of each wastestream. The wastehauler user charges for various wastestreams are as follows:

1. Septage and portable toilet wastes - The rate of $0.04 per gallon discharged will be assigned to all permitted septage and portable toilet wastehaulers.

2. Grease trap wastes - The rate of $0.05 per gallon discharged will be assigned to all permitted grease trap wastehaulers.

3. Sludge wastes - This rate will vary dependent on strength and volume. Sludge rates will be calculated using the parameter costs for the mixing tank location.

4. Miscellaneous Wastes -This rate will vary dependent on strength of waste, volume and discharge location.

These rates will be used for all permits effective July 1, 2021.

(n) In the event a person, lot, parcel of land, building or premises threatens to discharge or discharges sewage or waste into or near the Authority's publicly owned treatment works, either directly or indirectly, which in the opinion of the Authority will or is likely to bypass, upset, harm or endanger the facilities of the Authority, then such person or the owner or operator of such lot, parcel of land, building or premises shall pay to the Authority charges for any and all clean up, removal and remediation costs actually incurred by the Authority, including but not limited to labor, materials, equipment, insurances or laboratory services for the (i) containment or attempted containment of such discharge or threatened discharge, (ii) sampling and analysis of such discharge or threatened discharge, (iii) removal or attempted removal of such discharge or threatened discharge, (iv) taking of reasonable measures to prevent or mitigate damage to property, public health, safety or welfare, or (v) remediation, treatment, storage or disposal of such discharge or threatened discharge and all soils, water or structures affected by such discharge.

(o) All industrial users and wastehaulers shall pay to the Authority a charge for the actual costs of analysis incurred by the Authority for monitoring of any and all discharges of such users.

(p) Any person who is granted a temporary permit to discharge into the facilities of the Authority shall pay a permit fee of $800.00 to the Authority as a condition of the issuance of such permit.

(q) Except as otherwise defined herein, all terms and phrases used or contained in this schedule of sewer rents shall bear the same meaning and definition as set forth in the Authority's Sewer Use Regulations 21 N.Y.C.R.R. Part 10075 and New York Public Authorities Law Section 1175 et seq.

(r) Sewer rents and charges as herein provided shall be payable at the office of the Director of the Treasury for the City at Room 117, City Hall, Buffalo, New York 14202, or at such other location or address as may be set forth on the Authority's invoice, and shall become due and payable as follows:

1. So much of the sewer rents and charges as are based upon water use and the drainage connection service charge covering the respective premises, or such other charges as provided herein shall be due and payable, except as otherwise stated in this schedule or in such invoice, on the same day, one month following the month of the invoice billing date, and such invoice may be billed monthly, quarterly or as otherwise determined by the Authority; and

2. So much of the sewer rents and charges as are based upon the assessed valuation of chargeable real estate shall become due and payable from the first day of July 1938, and each year thereafter, and may be paid without interest on or before September 30th next succeeding.

(s) Such sewer rents and charges that remain unpaid after their respective due dates shall be charged interest, and such interest shall continue to be charged until such sewer rents and charges are paid in full, as follows:

1. sewer rents based upon water use and drainage connection service charges shall be charged interest at the same rate as unpaid City taxes, to wit: four and one-half percent (4.5%) interest shall be added to amounts unpaid from the first through the thirtieth day after the due date and thereafter one and one-half percent (1.5%) shall be added to all amounts that remain unpaid for each succeeding month;

2. sewer rents based upon assessed valuation of chargeable real estate that remain unpaid on October 1st of each year shall be charged interest at the rate of two percent (2%), and such sewer rents that remain unpaid shall be charged two percent (2%) for each month thereafter until paid; and

3. all other sewer rents and charges of the Authority shall be charged interest at the rate of one and one-half percent (1.5%) per month if not paid by the due date stated on the invoice issued by the Authority.

(t) All persons and property served by the Authority shall be subject to paying reasonable costs and expenses, including attorney fees incurred in the collection of sewer rents and charges that remain unpaid, as may be determined by the Board of the Authority. In addition to any other remedy or provision hereof, the Authority reserves the right to engage in such collection activities, as it deems appropriate, for all accounts that remain unpaid after the due date. In consideration of such collection activities and to defray the cost thereof with respect to accounts based on water use and drainage connection service, the person or property served by the Authority may pay an additional charge of twenty-one percent (21%) of the amount of each such delinquent account, together with interest as provided herein, that remains unpaid for more than (i) one hundred twenty (120) days from the due date for metered accounts, and (ii) two hundred ten (210) days from the due date for non-metered flat rate accounts. Due date, as used herein, means the date that the Authority's sewer rent and other charges are due and payable pursuant to III (q)(1) and III (q)(2), herein, respectively.

(u) Invoice statements shall be mailed or delivered to the address of the owner or user, as the case may be, as such address appears on the Authority's records. Such mailing or delivery is a matter of convenience. Failure of an owner or user to receive an invoice statement shall not release such owner or user from the obligation to pay such invoice statement, together with any other charges and interest which may accrue on unpaid amounts.

(v) All invoices shall be paid in United States dollars and may be paid by cash, check or credit card at Room 117, City Hall, Buffalo, New York or such other location or address as may be provided on such invoice, by internet, or by telephone as set forth on the invoice. All persons who pay through the City of Buffalo website or by telephone shall pay any processing fees charged by the City of Buffalo. Multiple payments in the same transaction will be charged the convenience fee only once. The convenience fee will be added automatically to each transaction.

IV. LIEN OF SEWER RENT From and after the due date thereof, such sewer rents and charges, together with any interest and collection costs shall constitute a lien upon the real property served by the facilities. Such lien shall have the same priority and superiority as the lien of the general tax of the City.

V. EFFECTIVE DATE OF THIS SCHEDULE This schedule of sewer rents and other charges shall become effective July 1, 2021; provided, however, that the sewer rents and other charges herein set forth, applicable to water use, shall become effective on all billings on and after August 1, 2021, excepting only monthly metered accounts for July 2021, and Section "W" of the quarterly metered accounts for the period May, June, and July 2021, which shall be billed according to the schedule of rents in effect prior to July 1, 2021.

1.0 INTRODUCTION

The Buffalo Sewer Authority (BSA) recently completed its development of a pretreatment program in conformance with the General Pretreatment Regulations (40CFR403). A formal application for the approval of this program has been prepared and submitted to both the United States Environmental Protection Agency (USEPA) and the New York State Department of Environmental Conservation (NYSDEC). Once this program has been approved, the BSA will have the primary responsibility of ensuring that all industrial users of the Authority's wastewater collection and treatment system comply with both the BSA pretreatment program requirements and the EPA categorical pretreatment standards.

The primary mechanism to be utilized by the BSA to ensure industrial compliance with its sewer use regulations will be industrial discharge limits which have been developed for various pollutants. This approach is mandated by the General Pretreatment Regulations (40CFR403.5(c)), which require that POTW's developing pretreatment programs derive and enforce specific local discharge limits which will be applied to all industrial users within the POTW's service area. The actual function of these local limits is to protect both the BSA POTW against interference from pollutants and the environment from pollutants which pass through the treatment facility. The BSA has opted to refine the limit development process by deriving critical (allowable) mass loadings for each control parameter addressed. This approach gives the industries more operational leeway regarding discharges and allows the BSA more flexibility in administering the pretreatment program while still protecting the BSA treatment plant.

The purpose of this report is to present the derivation and allocation of critical mass loadings for the control parameters identified in the BSA's Industrial Pretreatment Program report. Both the methodology used to develop this approach and the ramifications of its implementation are discussed.

2.0 METHODOLOGY

The methodology utilized to allocate the critical influent masses for specific control parameters identified in the BSA's Industrial Pretreatment Program is presented in detail in Appendix A. The process of deriving these critical masses is comprised of several basic steps. First is the determination of critical influent limits for the control parameters. Threshold pollutant concentrations which would either inhibit wastewater and sludge treatment processes, adversely impact sludge disposal practices or cause NYS water quality standards to be exceeded were calculated, taking into consideration the BSA POTW's ability to remove the identified pollutants. The critical limit for each pollutant was then determined to be the most restrictive of the threshold concentrations derived previously.

The second step is the development of specific industrial discharge limits based on the allocation of allowable pollutant mass loadings. The treatment plant critical influent mass was calculated using the POTW design hydraulic capacity (180 mgd) and the critical influent concentration for each pollutant. This quantity was then distributedbetween four loading categories: uncontrollable sources (domestic,natural background, etc.), present industrial users, an unallocated portion reserved for future industrial users and a non-allocated safety margin. The portion of the POTW's critical mass which has been allocated to the existing industrial users will be distributed according to each industry's discharge volume and pollutant loading. The mass limits designated for each industry will be implemented through the BSA's BPDES permit system, with all pollutant mass discharge restrictions being set forth in the respective discharge permits.

3.0 CRITICAL INFLUENT MASS ALLOCATION

3.1 Critical Influent Mass

The critical influent mass is the maximum amount of a pollutant that could be received at the POTW without any adverse effects being experienced. Generally, this mass is expressed as a loading rate, such as pounds per day. The critical influent mass for any pollutant is determined by multiplying the POTW's design hydraulic capacity (180 mgd) times the pollutant's critical influent concentration (limit) and the appropriate conversion factors to get the loading rate. The calculations made to obtain the critical masses listed in Table 1 are presented in Appendix B.

The critical influent mass is also the quantity which is apportioned among the four loading categories. These categories represent both the masses of pollutants which are being received at the treatment plant currently and additional amounts reserved for POTW protection and future industrial users. A description of each loading category follows.

3.2 Safety Factor

A safety factor equal to twenty percent of the critical influent mass has been set aside for each control parameter (except selenium)as a non-allocated reserve. This reserved amount provides a margin of safety to ensure both protection of the POTW and compliance with SPDES permit requirements.

3.3 Uncontrollable Source Mass

For each pollutant received at the POTW, a specific load is attributed to background sources such as eroded minerals and domestic/commercial discharges. These quantities of the pollutants cannot be controlled by the BSA through enforcement of sewer use regulations. Consequently, the uncontrollable mass of each pollutant has been subtracted from the total mass available for allocation to industrial users. The specific mass of pollutants from uncontrollable sources is calculated by multiplying the design hydraulic capacity of the POTW times the background concentration for each pollutant and the appropriate conversion factors. Background concentrations were obtained by sampling sewer flows in areas which were not downstream of any industrial sources. The analytical results were considered to be representative of natural background concentrations for all control parameters. In comparison, the results of a similar analytical program are shown in Table 2. As can be seen, the concentrations found in the BSA's system are quite similar to those obtained elsewhere.

One problem this approach has presented is that for PCB, BHC, pyrene and 1,2,4-dichlorobenzene, the background concentrations recorded were higher than the POTW's critical influent limits. This may indicate that the samples taken are not truly representative and that additional sampling should be completed, which seems to be the case since the critical influent limits for these parameters are not being exceeded in the treatment plant influent.

3.4 Allocated Mass

To determine the portion of the critical influent mass for each control parameter to be allocated to industrial users, data from the BSA's Pretreatment Program industrial survey were used. Various industrial users were sampled for parameters related to their specific manufacturing processes. From the available data, the loadings of each control parameter discharged to the POTW were calculated using an industry's discharge rate and detected pollutant concentrations. For each parameter, all industrial loads were complied to produce each respective allocated mass (Table 1). In cases where a categorical industry was discharging a pollutant at concentrations exceeding the appropriate categorical pretreatment standard discharge limits, the categorical limits were used for calculation purposes since this discharge level will be required once the BSA Pretreatment Program is approved by the USEPA. Calculations used to develop the allocated mass loading for each control parameter are presented in Appendix C.

To prevent an industry from discharging its total allowable daily loading over a short time period, (i.e., slug or batch discharges), maximum instantaneous discharge concentrations for each pollutant have been developed and included in both the BSA's Sewer Use regulations and all discharge permits.

3.5 Unallocated Mass

Following the calculation of the pollutant loadings which comprised the safety margin, uncontrollable source and allocated mass loading categories for each control parameter, a quantity of the respective critical influent masses remained unallocated. These unallocated masses remain reserved for any industries which may begin to discharge to the BSA system in the future or for the expansion of existing industries.

4.0 THE MASS ALLOCATION APPROACH

Under this mass allocation system, existing industrial sources will be allocated an allowable mass discharge limit equivalent to their present discharge level. Following Categorical Pretreatment Standard compliance dates, industries subject to the standards will be allocated a mass based on the regulated concentration limits and their respective discharge volumes. Should an existing industry expand its production level, its allowable mass discharge will be increased accordingly by giving it a portion of the unallocated mass reserve. .Similarly, if a new industry begins to operate within the BSA's service area, its allowable discharge mass would be taken from the unallocated mass reserve. Conversely, if an industry reduces or ceases production, its allocated mass which is lost would be placed into the unallocated reserve.

Table 1 is a summary table for the mass allocation of pollutants received by the BSA POTW. Each control parameter's critical influent mass is divided between the four loading categories. To help clarify the relationships between these categories for each parameter, pie charts are presented in Figures 1 through 16. As indicated, all of the control parameters except selenium exhibit considerable unallocated masses which are available for future industrial expansion. It is reasonable to expect from this information and in consideration of the industrial environment within the BSA's service area, that this approach to implementing the pretreatment program should operate adequately in the future. The selenium problem is one which must be addressed, but this will serve as a good test of the reallocation system which may be required again in the future.

The intent of the BSA in implementing the mass allocation approach is to provide a degree of flexibility to the administration of its pretreatment program. Benefits which may be realized initially by industry as a result of using mass allocation include the elimination of industry's need to install costly pretreatment facilities required to remove pollutants adequately handled by the POTW. In the future, if the POTW's critical influent mass for any of the control parameters should be reached or if the unallocated mass should be depleted, the BSA will have to reallocate the masses for the problem pollutant such that some industries may find it necessary to pretreat their wastewater to remain in compliance.

The mass of each specific pollutant that initially will be allocated to specific industrial users once this mass allocation system is implemented is presented in Appendix C. Presently, it is anticipated that all BPDES permits containing the specific mass limits will be issued during the first five (5) months following EPA/NYSDEC approval of the Authority's pretreatment program. (Assuming that program approval will be received during August 1984, all BPDES permits will be issued by January 1985.) Top priority will be given to issuance of BPDES permits to Electroplating and Metal Finishing facilities. Subsequently all other permits will be issued. The total number of BPDES permits to be issued is 222.

The primary function of the local pretreatment program is to provide a mechanism for the control of industrial pollutants which can have a significant adverse impact on the POTW or the receiving stream water quality. The development and enforcement of local industrial discharge limits are essential mechanisms for meeting these objectives. The development process basically involves identification of those operational, environmental and health and safety factors which are most sensitive to and could be most adversely impacted by industrial pollutants. Limits are then derived which are expressly designed to mitigate and prevent the potential for an adverse impact.

The methodology used to develop the limits which have been incorporated into the BSA Sewer Use Regulations are presented in this manual. All revisions of existing limits and development of additional limits will also be based on this methodology.

The approach to develop specific industrial discharge limits effort is based on initial determination of critical treatment plant influent concentrations necessary to meet the following objectives:

Critical influent limits developed on the basis of the basis of the criteria identified are used to derive critical mass loadings for each pollutant of concern. This mass is then allocated - in conjunction with the BSA BPDES permit system - to industrial contributors in the form of mass discharge limits.

The specific manner in which critical influent limits and industrial mass limits are developed is presented below.

Critical Influent Limits. Critical influent limits are developed for the BSA treatment plant using the methodology of Anthony and Breimhurst, 1981 (Ref.1). This methodology involves the following steps:

The specific manner in which this methodology is applied to derive limits to meet the previously stated objectives is presented below.

Inhibition of the Anaerobic Sludge Digestion Process - The pollutant concentrations which are limiting to the BSA anaerobic sludge digestion process are calculated on the basis of the methodology presented in Table 1. Values for C_s and R_p will be determined from the literature.

Table 1- Methodology for Calculation of Influent Concentration Limits Necessary to Prevent Inhibition of the BSA Anaerobic Sludge Digestion Process.

Inhibition of the Aerobic Process (Activated Sludge) - The pollutant concentrations which are inhibitory to the BSA activated sludge process will be calculated as shown in Table 2. Values for C_p and R _p will be determined from the literature.

Table 2- Methodology for Calculation of Influent Concentration Limits Necessary to Prevent Inhibition of the BSA Activated Sludge Process.

Limitation of Sludge Disposal Options - The BSA presently incinerates its wastewater treatment plant sludge and landfills the ash. Occasionally, when the incinerators aren't operating the sludge is landfilled. This situation is not expected to change in the foreseeable future. Therefore, the consideration of other sludge disposal options, such as landspreading, is impractical for purpose of defining limiting pollutant influent concentrations. Furthermore, no problems have been noted in the past which would adversely impact on continuation of the present practice of sludge disposal. For example, both the BSA sludge and incinerator ash have been tested for a hazardous. leachate potential (i.e. EP Toxicity test) and were determined to be nonhazardous. For these reasons, the development of limiting influent concentrations necessary to prevent limitation of sludge disposal options is not presently required.

Contravention of N.Y. State Water Quality Based Permit Limits - The BSA's most recent SPDES draft permit contains proposed water quality based discharge limitations for a number of pollutant parameters. The maximum treatment plant influent concentrations which could be allowed without violating such limits are calculated as shown in Table 3. Values for C _e are taken directly from the BSA's SPDES permit. Values for R _o will be determined on the basis of historical BSA treatment plant data.

Table 3- Methodology for Calculation of Influent Limits Necessary to Prevent Contravention of proposed NYS Water Quality Permit Limits.

Violation of Incinerator Emission Standards - Since the BSA incinerates its sludge it is subject to the National Emission Standards for Hazardous Air Pollutants (40 CFR Part 61). Review of these standards indicates that mercury is presently the only pollutant parameter which is pertinent to BSA's situation. The methodology for determination of the maximum treatment plant influent concentration which could be allowed without violating the mercury emission standard is presented in Table 4.

Table 4- Methodology for Calculation of Influent Limits Necessary to Prevent Violation of Incinerator Emission Standards.

The value for I _s is determined from the 40 CFR 61 regulations, section 61.52. The value for V_p is determined from the literature (Ref. 2). Values for Q _ip and Q are determined on the basis of BSA Treatment Plant data and information. The value for R _o is determined on the basis of historical BSA treatment plant data.

Summary of Critical Limits - The critical limit for each pollutant is defined as the most restrictive of the limiting concentrations derived on the basis of the criteria and methodology identified above.

Industrial Limits - The approach used to develop specific industrial discharge limits is based on derivation and allocation of critical pollutant (allowable) mass loadings. The treatment plant critical influent mass is determined on the basis of the critical influent concentration and the treatment plant hydraulic design capacity (e.g. 180 MGD) according to the following relationship:

Critical Inf. Limit (mg/l) × g/1000 mg × 1b/454 g × 3.785 l/gal. × hydraulic design capacity (180 MGD) =Critical Inf. Mass

To determine the quantity of the critical mass available for allocation to industrial users, the mass contributed by uncontrollable sources (domestic sources, etc.) is subtracted. Twenty percent of the critical influent mass is also subtracted and permanently set aside as a nonallocated reserve to provide a margin of safety for treatment plant protection and compliance with SPDES permit water quality based limits.

Under this mass allocation system, existing industrial sources will be allocated an allowable mass discharge limit equivalent to their present level of discharge. (Following Categorical Pretreatment Standard Compliance Dates, industries subject to such standards will be allocated a mass based on the regulated concentration limits and each industry's volume of discharge.) All unallocated mass will be set aside in an unallocated mass reserve. This situation allows the BSA to exercise flexibility in administration of this system. For example, when an existing industry expands its production level, its allowable mass discharge could be increased accordingly by giving that industry a portion of the unallocated mass reserve. Likewise, when a new industry moves into the BSA service area, its allowable mass discharge would also be drawn from the unallocated mass reserve. Conversely, when an existing industry moves out of the BSA service area, its mass allocation would be placed back into the unallocated mass reserve.

The mass allocation system described above is specifically designed to protect the treatment plant and receiving stream water quality without imposing unnecessary regulatory restrictions on industry. This system is especially intended to eliminate the need for industry to install costly pretreatment facilities to remove pollutants that are being adequately removed at the BSA treatment plant and that are not present in the treatment plant influent at levels that could have an adverse impact on the treatment plant operation. If, however, the treatment plant critical influent limit for any pollutant is approached or the mass reserve depleted, the BSA will reallocate the mass for that pollutant such that some industries may find it necessary to pretreat their wastewater to remove that pollutant.

The mass limits allocated to each industry will be implemented through the BSA BPDES permit system. All pollutant mass discharge restrictions will be set forth in each industry's permit. To prevent an industry from discharging its total allowable daily mass over a short period of time (i.e. slug or batch discharges), maximum instantaneous discharge concentration limits for each pollutant parameter will also be placed in each permit and the Sewer Use Regulations. The slug discharge limits have been determined on the basis of the following relationship:

Values for R are obtained from the results of the industrial survey. Specifically, the industrial sources of each of the pollutants have been determined on the basis of the wastewater discharge analyses submitted by all the significant industrial users in the BSA service area, including the outlying service areas. Then, for each individual pollutant, the total volume of wastewater from all industrial sources of that pollutant was determined. Each value for R was then determined by dividing the total volume of wastewater received at the BSA treatment plant by the total volume of industrial wastewater containing a given pollutant.

To determine the background concentrations (B) of pollutants (i.e. pollutant quantities from uncontrollable sources such as private residential areas, commercial establishments and storm water runoff), samples of sewerage were collected for subsequent analysis from locations in the BSA sewer system that contained no industrial wastes.

STP DESIGN HYDRAULIC CAPACITY X CRITICAL INFLUENT LIMIT × 8.345 lb/mg = CRITICAL INFLUENT MASS

Cadmium: 180 mgd × 0.45 mg/l × 8.345 lb/mg = 675.95 lb/d

Chromium (Total): 180 mgd × 0.72 mg/l × 8.345 lb/mg = 1,081.51 lb/d

Chromium (He×): 180 mgd × 0.17 mg/l × 8.345 lb/mg = 255.36 lb/d

Copper: 180 mgd × 0.27 mg/l × 8.345 lb/mg = 405.57 lb/d

Lead: 180 mgd × 0.77 mg/l × 8.345 lb/mg = 1,156.62 lb/d

Mercury: 180 mgd × 0.0047 mg/l × 8.345 lb/mg = 7.06 lb/d

Nickel: 180 mgd × 0.11 mg/l × 8.345 lb/mg = 165.23 lb/d

Selenium: 180 mgd × 0.0117 mg/l × 8.345 lb/mg = 17.58 lb/d

Silver: 180 mgd × 0.89 mg/l × 8.345 lb/mg = 1,336.87 lb/d

Zinc: 180 mgd × 0.57 mg/l × 8.345 lb/mg = 856.20 lb/d

Cyanide (Total): 180 mgd × 0.22 mg/l × 8.345 lb/mg = 330.46 lb/d

Cyanid (Amen): 180 mgd × 0.02 mg/l × 8.345 lb/mg = 30.04 lb/d

Chloroform: 180 mgd × 0.047 mg/l × 8.345 lb/mg = 70.60 lb/d

Fluoranthene: 180 mgd × 0.0067 mg/l × 8.345 lb/mg = 10.05 lb/d

Endosulfan: 180 mgd × 0.0003 mg/l × 8.345 lb/mg = 0.45 lb/d

DDD: 180 mgd × 0.00013 mg/l × 8.345 lb/mg = 0.20 lb/d