Section NR 211.11 - Categorical pretreatment standards(1) Categorical pretreatment standards for specific point source categories are set forth in chs. NR 221 to 297. Limits in categorical pretreatment standards shall apply to the effluent from the process regulated by the standard, unless otherwise specified in the standard. Limits in categorical pretreatment standards shall apply to wastestreams which are transported off-site for disposal as well as those discharged on-site. Industrial users shall comply with applicable categorical pretreatment standards, in addition to complying with the general prohibitions established in s. NR 211.10, unless specifically noted otherwise in the categorical pretreatment standard.(2) COMPLIANCE DATES. (a) All industrial users, except new sources, shall comply with the applicable categorical pretreatment standards within 3 years from the effective date of the standard or within a shorter time period if specified in the applicable standard. A direct discharger which becomes an industrial user after promulgation of an applicable categorical pretreatment standard may not be considered a new source unless it falls within the definition of a "new source"contained in s. NR 211.03(9).(b) New sources shall install, have in operating condition and start up all of the pollution control equipment required to meet the applicable pretreatment standards before beginning discharge. Within the shortest feasible time, not to exceed 90 days, new sources shall meet all applicable pretreatment standards.(3) CONVERSION TO EQUIVALENT MASS OR CONCENTRATION STANDARDS.(a)1. When the limits in a categorical pretreatment standard are expressed only in terms of mass of pollutant per unit of production, the control authority may convert the limits to equivalent limitations expressed either as mass of pollutant discharged per day or effluent concentration for purposes of calculating limits for individual users.2. Equivalent mass per day limits shall be calculated by multiplying the limits in the standard by the industrial user's average rate of production. This average rate of production shall be based upon a reasonable measure of the industrial user's actual long-term daily production, such as average daily production, during a representative year. For new sources, actual production shall be estimated using projected production.3. Equivalent concentration limits shall be calculated by dividing the mass limits derived according to subd. 2. by the average daily flow rate of the industrial user's process wastewater. This average daily flow rate shall be based upon a reasonable measure of the industrial user's actual long-term average flow rate, such as the average daily flow rate during the same representative year used in subd. 2.4. When pretreatment standards specify both daily and long-term limits, the same production or flow figures shall be used in calculating daily and long-term equivalent limits.5. Any industrial user operating under a control mechanism incorporating equivalent mass or concentration limits calculated from a production based standard shall notify the control authority within 2 business days after the industrial user has reason to know that the production level will significantly change within the next calendar month. Any industrial user which does not notify the control authority of such anticipated change shall meet the mass or concentration limits in its control mechanism that were based on the original estimate of the long-term average production rate.(bm)1. When the limits in a categorical pretreatment standard are expressed only in terms of pollutant concentrations, an industrial user may request that the control authority convert the limits to equivalent mass limits. The determination to convert concentration limits to mass limits is within the discretion of the control authority. The control authority may establish equivalent mass limits only if the industrial user: a. Employs or demonstrates that it will employ water conservation methods and technologies that substantially reduce water use during the term of its control mechanism;b. Uses control and treatment technologies that are adequate to achieve compliance with the applicable categorical pretreatment standard, and has not used dilution as a substitute for treatment;c. Provides 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. Both the actual average daily flow rate and the long-term average production rate shall be representative of current operating conditions;d. Does 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; ande. Has consistently complied with all applicable categorical pretreatment standards during the period prior to the industrial user's request for equivalent mass limits.2. Upon approval by the control authority an industrial user subject to equivalent mass limits shall: 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 control authority whenever production rates are expected to vary by more than 20 percent from its baseline production rates determined in subd.1. c. Upon notification of a revised production rate, the control authority shall reassess the equivalent mass limit and revise the limit as necessary to reflect changed conditions at the facility; andd. Continue to employ the same or comparable water conservation methods and technologies as those implemented pursuant to subd. 1. a. so long as it discharges under an equivalent mass limit.3. A control authority which chooses to establish equivalent mass limits: a. Shall calculate the equivalent mass limit by multiplying the actual average daily flow rate of the regulated processes 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, shall reassess the equivalent mass limit and recalculate the limit as necessary to reflect changed conditions at the facility; andc. May retain the same equivalent mass limit in subsequent control mechanism 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 as prohibited by s. NR 211.10(4). The industrial user shall also be in compliance with s. NR 211.19.4. A control authority may not express limits in terms of mass for pollutants such as pH, temperature, radiation, or other pollutants which cannot appropriately be expressed as mass. (cm) The control authority may convert the mass limits of the categorical pretreatment standards in chs. NR 233, 235, and 279 to equivalent concentration limits. When converting such limits to concentration limits, the control authority shall use the concentrations listed in the applicable subparts of chs. NR 233, 235, and 279 and document that dilution is not being substituted for treatment as prohibited by s. NR 211.10(4).(d) Equivalent limitations calculated in accordance with par. (a) , (bm), or (cm) are deemed pretreatment standards for the purposes of this chapter and s. 283.21(2), Stats. The control authority shall document how the equivalent limits were derived and make this information available to the public. Once incorporated into its control mechanism, the industrial user shall comply with the equivalent limitations in lieu of the promulgated categorical standards from which the equivalent limitations were derived. (e) When pretreatment standards specify both maximum daily and maximum average limits, the same production or flow figures shall be used in calculating maximum daily and maximum average limits.(4) COMPENSATION FOR POLLUTANTS IN INTAKE WATER.(a) Categorical pretreatment standards may be adjusted to reflect the presence of pollutants in an industrial user's intake water if the applicable categorical pretreatment standards specifically provide that they may be applied on a net basis or if the industrial user demonstrates to the control authority that: 1. The control system used or proposed to meet the categorical pretreatment standards would meet the categorical pretreatment standards in the absence of pollutants in the intake water if the control system is properly installed and operated;2. The constituents of a generic measure, such as BOD, TSS or oil and grease, in the industrial user's effluent are substantially similar to the constituents of the generic measure in the intake water. The control authority may waive this requirement if appropriate additional limits are placed on process water pollutants either at the point of discharge or elsewhere; and3. The intake water is drawn from the same water body as the water body to which the POTW discharges. The control authority may waive this requirement if it finds that no environmental de-gradation will result.(b) The control authority shall grant credits only to the extent necessary to meet the applicable categorical pretreatment standards, up to a maximum value equal to the influent value. The control authority may require additional monitoring to determine eligibility for credits and compliance with the adjusted standards.Wis. Admin. Code Department of Natural Resources § NR 211.11
Amended by, Cr. Register, July, 1983, No. 331, eff. 8-1-83; am. (1), r. and recr. (2) and (3), cr. (4), Register, March, 1992, No. 435, eff. 4-1-92; CR 13-006: am. (3) (title), cr. (3) (a) 5., r. (3) (b), cr. (3) (bm), r. (3) (c), cr. (3) (cm), (d), (e), am. (4) (a) (intro.) Register January 2014 No. 697, eff. 2-1-14.