NR 211.11(3)(a)3.
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. NR 211.11(3)(a)4.
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.
NR 211.11(3)(a)5.
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.
NR 211.11(3)(bm)1.1. 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:
NR 211.11(3)(bm)1.a.
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;
NR 211.11(3)(bm)1.b.
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;
NR 211.11(3)(bm)1.c.
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;
NR 211.11(3)(bm)1.d.
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; and
NR 211.11(3)(bm)1.e.
e. Has consistently complied with all applicable categorical pretreatment standards during the period prior to the industrial user's request for equivalent mass limits.
NR 211.11(3)(bm)2.
2. Upon approval by the control authority an industrial user subject to equivalent mass limits shall:
NR 211.11(3)(bm)2.a.
a. Maintain and effectively operate control and treatment technologies adequate to achieve compliance with the equivalent mass limits;
NR 211.11(3)(bm)2.b.
b. Continue to record the facility's flow rates through the use of a continuous effluent flow monitoring device;
NR 211.11(3)(bm)2.c.
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; and
NR 211.11(3)(bm)2.d.
d. 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.
NR 211.11(3)(bm)3.
3. A control authority which chooses to establish equivalent mass limits:
NR 211.11(3)(bm)3.a.
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;
NR 211.11(3)(bm)3.b.
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; and
NR 211.11(3)(bm)3.c.
c. 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.
NR 211.11(3)(bm)4.
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.
NR 211.11(3)(cm)
(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).
NR 211.11(3)(d)
(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.
NR 211.11(3)(e)
(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.
NR 211.11(4)
(4) Compensation for pollutants in intake water. NR 211.11(4)(a)(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:
NR 211.11(4)(a)1.
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;
NR 211.11(4)(a)2.
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; and
NR 211.11(4)(a)3.
3. 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.
NR 211.11(4)(b)
(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.
NR 211.11 History
History: 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.
NR 211.12(1)(1)
Where effluent from a process regulated by a categorical pretreatment standard is mixed prior to treatment with wastewaters other than those generated by the regulated process, fixed alternative discharge limits may be established by the control authority or by the industrial user with the written concurrence of the control authority. These alternative limits shall apply to the mixed effluent. When deriving alternative categorical limits, the control authority or industrial user shall calculate both an alternative daily maximum value using the daily maximum values specified in the appropriate categorical pretreatment standards and an alternative monthly average value using the monthly average values specified in the appropriate categorical pretreatment standards. The industrial user shall comply with the alternative daily maximum and monthly average limits approved by the control authority until the control authority modifies the limits or approves an industrial user modification request. Modification is authorized whenever there is a material or significant change in the values used in the calculation to fix alternative limits for the regulated pollutant. An industrial user shall immediately report any such material or significant change to the control authority. New alternative categorical limits shall be calculated within 30 days.
NR 211.12(2)
(2) Alternative limit calculation. Alternative limits shall be derived according to the following formulas:
NR 211.12(2)(c)1.
1. Boiler blowdown, non-contact cooling, stormwater and demineralizer backwash streams. However, if these streams contain a significant amount of a pollutant and if the combination of these streams with an industrial user's regulated process waste-stream prior to treatment will result in a substantial reduction of that pollutant, the control authority, upon the industrial user's application, shall determine whether these streams should be classified as diluted or unregulated. In its application to the control authority, the industrial user shall provide engineering, production, sampling and analysis and other information necessary for the control authority to make its determinations;
NR 211.12(2)(c)2.
2. Sanitary wastestreams where the streams are not regulated by a categorical pretreatment standard; or
NR 211.12(2)(c)3.
3. Any process wastestreams which were or could have been entirely exempted from categorical pretreatment standards for one or more of the following reasons:
NR 211.12(2)(c)3.a.
a. The pollutants regulated by the categorical pretreatment standards used in the formula are not detectable in the effluent from the industrial user;
NR 211.12(2)(c)3.b.
b. The pollutants of concern are present only in trace amounts and are neither causing nor likely to cause toxic effects;
NR 211.12(2)(c)3.c.
c. The pollutants of concern are present in amounts too small to be effectively reduced by technologies known to the administrator of EPA; or
NR 211.12(2)(c)3.d.
d. The wastestream contains only pollutants that are compatible with the POTW.
NR 211.12(3)
(3) Alternate limits below detection limit. An alternative pretreatment limit may not be used if the alternative limit is below the analytical detection limit for any of the regulated pollutants.
NR 211.12(4)
(4) Self-monitoring. Self-monitoring to insure compliance with the alternative categorical limit shall be conducted in accordance with s.
NR 211.15 (4).
NR 211.12(5)(a)(a) If a treated regulated process wastestream is combined with wastewaters other than those generated by the regulated process, the industrial user may monitor either the segregated process wastestream or the combined wastestream for purposes of determining compliance with the applicable pretreatment standards. If the industrial user chooses to monitor the segregated process wastestream, the industrial user shall apply the applicable categorical pretreatment standard. If the industrial user chooses to monitor the combined wastestream, the industrial user shall apply an alternative discharge limit calculated according to the combined wastestream formula in sub.
(2).
NR 211.12(5)(b)
(b) An industrial user may change monitoring points only after receiving approval from the control authority. The control authority shall ensure that any change in an industrial user's monitoring point will not allow the industrial user to substitute dilution for adequate treatment.
NR 211.12 History
History: Cr.
Register, September, 1986, No. 369, eff. 10-1-86; am. (1), r. and recr. (2) and (4), cr. (5) and (6),
Register, March, 1992, No. 435, eff. 4-1-92;
CR 13-006: r. (6)
Register January 2014 No. 697, eff. 2-1-14.
NR 211.13(1)(a)
(a) Any POTW receiving wastes from an industrial user to which a categorical pretreatment standard applies may, subject to the conditions of this section, grant removal credits for removal by the POTW of pollutants specified in the categorical pretreatment standard. The POTW may grant a removal credit equal to or less than its consistent removal rate. Upon being granted a removal credit, each affected industrial user shall calculate its revised discharge limits in accordance with par.
(c).
NR 211.13(1)(b)1.
1. The POTW applies for and receives authorization from the department to give a removal credit in accordance with the requirements and procedures specified in sub.
(5). Removal credits may only be given for indicator or surrogate pollutants regulated in a categorical pretreatment standard if the categorical pretreatment standard so specifies.
NR 211.13(1)(b)2.
2. The POTW demonstrates and continues to achieve consistent removal of the pollutant in accordance with sub.
(2).
NR 211.13(1)(b)3.
3. Except as provided in sub.
(7), the POTW has an approved pretreatment program as required by this chapter; however, a POTW which does not have an approved pretreatment program may, pending approval of such a program, conditionally give credits as provided in sub.
(4).
NR 211.13(1)(b)4.
4. The granting of removal credits will not cause the POTW to violate the local, state and federal sludge requirements which apply to the sludge management method chosen by the POTW. Alternatively, the POTW can demonstrate to the department that even though it is not presently in compliance with applicable sludge requirements, it will be in compliance when the industrial user to whom the removal credit would apply is required to meet its modified categorical pretreatment standard.
NR 211.13(1)(b)5.
5. The granting of removal credits will not cause a violation of the POTW's permit limitations or conditions. Alternatively, the POTW can demonstrate to the department that even though it is not presently in compliance with applicable limitations and conditions in its WPDES permit, it will be in compliance when the industrial user to whom the removal credit would apply is required to meet its modified categorical pretreatment standard.
NR 211.13(1)(b)6.
6. The granting of removal credits will not result in a discharge of pollutants to waters of the state greater than the discharge that would be allowed if the pollutants were discharged other than through a POTW.
NR 211.13(1)(c)
(c) Revised discharge limits for a specific pollutant shall be derived by use of the following formula:
y = x
l-r
where:
x = pollutant discharge limit specified in the applicable
categorical pretreatment standard.
r = removal credit for that pollutant as established under
sub. (2) (percentage removal expressed as a proportion, i.e., a number between 0 and 1).
y = revised discharge limit for the specified pollutant
(expressed in same units as x).
NR 211.13(2)
(2) Demonstration of consistent removal. In order to demonstrate consistent removal, the POTW shall, for each pollutant [for] which removal credit authorization is sought, collect influent and effluent data and calculate consistent removal in accordance with the following requirements:
NR 211.13(2)(a)
(a) At least 12 representative samples of influent and effluent shall be taken at approximately equal intervals throughout one full year. Sampling shall be evenly distributed over the days of the week to include non-work days as well as work days. Upon concurrence of the department, a POTW may utilize a historical data base either in lieu of or as a supplement to these 12 samples. In order to be approved, the historical data base shall represent the yearly and seasonal conditions to which the POTW is subject and the POTW's performance for at least one year. Alternatively, a POTW, upon approval of the department, may utilize an alternative sampling design, if the samples to be taken represent the POTW's normal operating conditions and the different seasonal conditions to which the POTW is subject.
NR 211.13(2)(b)
(b) The POTW shall use the composite sampling method unless the grab sampling method is more appropriate.
NR 211.13(2)(b)1.a.a. Influent and effluent operational data should be obtained through 24-hour flow proportional composite samples. Sampling may be done manually or automatically, and discretely or continuously. If discrete sampling is employed, at least 12 aliquots shall be composited. Discrete sampling may be flow proportioned either by varying the time interval between each aliquot or the volume of each aliquot. All composites shall be flow proportional to either the stream flow at the time of collection of the influent aliquot or to the total influent flow since the previous influent aliquot. Volatile pollutant aliquots shall be combined in the laboratory immediately before analysis.
NR 211.13(2)(b)1.b.
b. Effluent sample collection need not be delayed to compensate for hydraulic detention. However, the POTW may elect to include detention time compensation or the department may require detention time compensation. The department may require that each effluent sample is taken approximately one detention time later than the corresponding influent sample if necessary to represent actual POTW operation. The detention period shall be based on a 24-hour average daily flow value. The average daily flow shall be based on the average of the daily flows during the same month of the previous year.
NR 211.13(2)(b)2.
2. Grab method. If composite sampling is not an appropriate technique, grab samples shall be taken to obtain influent and effluent operational data. A grab sample is an individual sample collected over a period of time not exceeding 15 minutes. The collection of influent grab samples shall precede the collection of effluent samples by approximately one detention period except that where the detention period is greater than 24 hours such staggering of the sample collection may not be necessary or appropriate. The detention period shall be based on a 24-hour average daily flow value. The average daily flow shall be based upon the average of the daily flows during the same month of the previous year. Grab sampling shall be employed where the pollutants being evaluated are those which may not be held for an extended period because of biological, chemical or physical interaction after sample collection which affects the results.
NR 211.13 Note
Note: Examples: Cyanide and phenol.
NR 211.13(2)(c)
(c) The POTW shall analyze the samples for pollutants in accordance with the analytical techniques prescribed in ch.
NR 219. If ch.
NR 219 does not contain analytical techniques for the pollutant in question, or if the department determines that ch.
NR 219 analytical techniques are inappropriate, the analysis shall be performed using validated analytical methods or any other applicable analytical procedures approved by the department including procedures suggested by the POTW.
NR 211.13(2)(d)1.1. For purposes of this paragraph “measurable" refers to the ability of the analytical method to quantify as well as identify the presence of the pollutant in question. “Limit of detectability" refers to the lowest limit at which the analytical method can quantify the pollutant in question.
NR 211.13(2)(d)2.
2. For each sample, removal shall be calculated by dividing the difference between the concentrations of a pollutant in the POTW's influent and effluent by the influent concentration. If the number of samples with measurable concentrations is greater than 12, the consistent removal is the average of the lowest half of the removals. If the number of samples with measurable concentrations is between 8 and 12, the consistent removal is the average of the lowest 6 removals. If less than 8 samples have measurable concentrations, the department may approve a means for demonstrating consistent removal on a case-by-case basis.
NR 211.13(2)(d)3.
3. If a substance is measurable in the influent but not in the effluent, the effluent concentration may be assumed to be the limit of measurement, and those data may be used by the POTW, subject to approval by the department.
NR 211.13(2)(d)4.
4. When calculating consistent removal, the POTW shall use all of the data obtained for measuring removal, except for measurements in which a substance is not measurable in the influent.
NR 211.13(2)(e)
(e) If an overflow of untreated water to receiving water occurs at least once per year, a POTW may claim consistent removal only by complying with either subd.
1. or
2., except as provided in subd.
3. NR 211.13(2)(e)1.a.
a. All industrial users to which the POTW proposes to apply removal credits have demonstrated the ability to contain or reduce discharges or increase pretreatment to compensate for the removal not being provided by the POTW during circumstances in which overflow can be reasonably expected to occur;
NR 211.13(2)(e)1.b.
b. The POTW has identified circumstances in which an overflow event can be reasonably expected to occur and has a notification plan or other viable plan to ensure that industrial users will learn of an impending overflow event in sufficient time to contain or reduce discharges or increase pretreatment to prevent untreated overflow from occurring;
NR 211.13(2)(e)1.c.
c. The POTW will monitor and verify the data required in subd.
1. d. to ensure that industrial users are containing or reducing discharges or pretreatment during overflow events; and
NR 211.13(2)(e)1.d.
d. All industrial users to which the POTW proposes to apply removal credits have demonstrated the ability and commitment to collect and make available, upon request, to the POTW, department or EPA, daily flow reports or other data sufficient to demonstrate that all discharges from regulated processes containing the pollutant for which the removal credit is requested were contained, reduced or subject to increased pretreatment during all circumstances in which an overflow was reasonably expected to occur.
NR 211.13(2)(e)2.a.a. The consistent removal calculated according to par.
(d) is reduced according to the following equation:
rc = rm 8760 - Z
8760
NR 211.13(2)(e)2.b.
b. The POTW is complying with all WPDES permit requirements and any additional requirements in any order or decree issued pursuant to the Federal Water Pollution Control Act, (33 U.S. Code section 1251
et seq.), (Clean Water Act), affecting combined sewer outflows. These requirements include, but are not limited to, any requirements contained in EPA's Combined Sewer Overflow Control Policy.
NR 211.13(2)(e)3.
3. This paragraph does not apply if the industrial user can show that overflow does not occur between the industrial user and the POTW treatment plant.
NR 211.13(3)
(3) Provisional credits. For pollutants which are not discharged currently (i.e., new or modified facilities, or production changes) the POTW may apply for authorization to give removal credits prior to the initial discharge of the pollutant. Consistent removal for the first 18 months of discharge shall be based on data from treatability studies or demonstrated removal at other treatment facilities where the quality and quantity of influent are similar. Eighteen months after initial discharge of pollutants, consistent removal shall be demonstrated pursuant to the requirements of sub.
(2). If the POTW cannot demonstrate consistent removal pursuant to the requirements of sub.
(2), the authority to grant provisional removal credits shall be terminated by the department. All industrial users to whom the revised discharge limits had been applied shall achieve compliance with the applicable categorical pretreatment standards within a reasonable time, not to exceed the period of time prescribed in the applicable categorical pretreatment standards, as may be specified by the department.
NR 211.13(4)
(4) Terms and conditions for POTW granting and continuing conditional removal credits. A POTW required to develop a local pretreatment program by s.
NR 211.20 may give removal credits pending approval of the program under the following terms and conditions:
