A. National categorical pretreatment standards as promulgated and amended by the U.S. environmental protection agency (EPA) pursuant to the act and found in 40 CFR chapter 1, subchapter N, parts 405 through 471 are hereby incorporated and shall be enforceable by this chapter.
1. All pollutant analyses, including sampling techniques, to be submitted as part of a wastewater discharge permit application or report shall be performed in accordance with the techniques prescribed in 40 CFR Part 136 and amendments thereto, unless otherwise specified in an applicable categorical Pretreatment Standard.
B. The collection and testing of the wastewater shall be done in accordance with the newest edition of the three (3) following publications:
1. “Standard Methods For The Examination Of Water And Wastewater” as published jointly by the American Water Works Association, the American Public Health Associations and the Water Pollution Control Federation.
2. American Society For Testing Materials, “ASTM Standards, Part 23, Water, Atmospheric Analysis”.
3. Environmental protection agency, water quality office, analytical control laboratory, “Methods For Chemical Analysis Of Water Wastes”.
C. A CIU may obtain a net/gross adjustment to a categorical Pretreatment Standard in accordance with the following paragraphs.
1. Categorical Pretreatment Standards may be adjusted to reflect the presence of pollutants in the Industrial User’s intake water by making an application to the Wastewater Superintendent. Upon request of the Industrial User, the applicable Standard will be calculated on a “net” basis (i.e., adjusted to reflect credit for pollutants in the intake water) if the following requirements of this Section are met.
2. Criteria:
a. Either (i) The applicable categorical Pretreatment Standards contained in 40 CFR subchapter N specifically provide that they shall be applied on a net basis; or (ii) The Industrial User demonstrates that the control system it proposes or uses to meet applicable categorical Pretreatment Standards would if properly installed and operated, meet the Standards in the absence of pollutants in the intake waters.
b. Credit for generic pollutants such as biochemical oxygen demand (BOD), total suspended solids (TSS), and oil and grease should not be granted unless the Industrial User demonstrates that the constituents of the generic measure in the User’s effluent are substantially similar to the constituents of the generic measure in the intake water or unless appropriate additional limits are placed on process water pollutants either at the outfall or elsewhere.
c. Credit shall be granted only to the extent necessary to meet the applicable categorical Pretreatment Standard(s), up to a maximum value equal to the influent value. Additional monitoring may be necessary to determine eligibility for credits and compliance with the Standard(s) adjusted under this Section.
d. Credit shall be granted only if the User demonstrates that the intake water is drawn from the same body of water as that into which the POTW discharges. The City may waive this requirement if it finds that no environmental degradation will result.
D. The Wastewater Superintendent may convert the mass limits of the categorical Pretreatment Standards of 40 CFR Parts 414, 419, and 455 to concentration limits for purposes of calculating limitations applicable to individual Industrial Users. The conversion is at the discretion of the Wastewater Superintendent.
E. When a categorical Pretreatment Standard is expressed only in terms of pollutant concentrations, an Industrial User may request that the City convert the limits to equivalent mass limits. The determination to convert concentration limits to mass limits is within the discretion of the Wastewater Superintendent.
1. To be eligible for equivalent mass limits, the Industrial User must:
a. Employ, or demonstrate that it will employ, water conservation methods and technologies that substantially reduce water use during the term of its wastewater discharge permit;
b. Currently use control and treatment technologies adequate to achieve compliance with the applicable categorical Pretreatment Standard, and not have used dilution as a substitute for treatment;
c. Provide sufficient information to establish the facility’s actual average daily flow rate for all waste streams, based on data from a continuous effluent flow monitoring device, as well as the facility’s long-term average production rate.
d. Both the actual average daily flow rate and the long-term average production rate must be representative of current operating conditions;
e. Not have daily flow rates, production levels, or pollutant levels that vary so significantly that equivalent mass limits are not appropriate to control the Discharge; and
f. Have consistently complied with all applicable categorical Pretreatment Standards during the period prior to the Industrial User’s request for equivalent mass limits.
2. An Industrial User subject to equivalent mass limits must:
a. Maintain and effectively operate control and treatment technologies adequate to achieve compliance with the equivalent mass limits;
b. Continue to record the facility’s flow rates through the use of a continuous effluent flow monitoring device;
c. Continue to record the facility’s production rates and notify the Wastewater Superintendent whenever production rates are expected to vary by more than 20 percent from its baseline production rates determined in paragraph 2.2F(1)(c) of this Section. Upon notification of a revised production rate, the Wastewater Superintendent will reassess the equivalent mass limit and revise the limit as necessary to reflect changed conditions at the facility; and
d. Continue to employ the same or comparable water conservation methods and technologies as those implemented pursuant to paragraphs 13.10.050(I)(1)(a) of this Section so long as it discharges under an equivalent mass limit.
3. When developing equivalent mass limits, the Wastewater Superintendent:
a. Will calculate the equivalent mass limit by multiplying the actual average daily flow rate of the regulated process(es) of the Industrial User by the concentration-based Daily Maximum and Monthly Average Standard for the applicable categorical Pretreatment Standard and the appropriate unit conversion factor;
b. Upon notification of a revised production rate, will reassess the equivalent mass limit and recalculate the limit as necessary to reflect changed conditions at the facility; and
c. May retain the same equivalent mass limit in subsequent individual wastewater discharge permit terms if the Industrial User’s actual average daily flow rate was reduced solely as a result of the implementation of water conservation methods and technologies, and the actual average daily flow rates used in the original calculation of the equivalent mass limit were not based on the use of dilution as a substitute for treatment pursuant to Section 13.10.080. The Industrial User must also be in compliance with Section 13.10.250 regarding the prohibition of bypass.] (Ord. 1526 § 4, 2023: Ord. 1056, 1992)