Section 212.76. Establishing WQBELs for publicly and privately owned wastewater facilities or treatment works.

 

(1)   WQBEL calculation procedures. Calculation of WQBELs derived from TMDL wasteload allocations shall be derived consistent with the wasteload allocation and assumptions of an EPA-approved TMDL. The department shall use scientifically defensible methods to calculate these WQBELs. All of the following conditions shall apply when calculating WQBELs derived from TMDL wasteload allocations:

(a) WQBELs shall be expressed as mass limitations unless the pollutant cannot appropriately be expressed by mass or a mass limitation is infeasible because the mass of the pollutant cannot be related to a measure of operation.

(b) When establishing WQBELs in permits the department shall ensure that substances are not present in amounts that are acutely toxic to animals, plants, or aquatic life in all surface waters including those portions of the mixing zone normally habitable by aquatic life and effluent channels as required by s. NR 102.04 (1) .

(c) When establishing WQBELs in permits the department shall ensure that substances are not exceeding applicable chronic toxicity criteria, wildlife criteria, taste and odor criteria, human threshold criteria, human cancer criteria, and secondary values, as specified in chs. NR 102 to 105 , after dilution with an appropriate allowable quantity of receiving water flow unless the conditions specified in s. NR 102.05 (3) or the TMDL wasteload allocation require less dilution or no dilution be allowed. WQBELs may be more restrictive than the applicable water quality criteria in order to be consistent with the wasteload allocation and assumptions of an EPA-approved TMDL.

(2)   WQBEL calculation procedures in Great Lakes basin. In addition to the requirements in sub. (1) , WQBELs derived from TMDLs under ss. NR 212.74 and 212.75 shall also meet all of the following:

(a) WQBELs shall be sufficiently stringent to ensure that accumulation of the pollutant of concern cannot occur in sediments at levels injurious to designated or existing uses, human health, wildlife, or aquatic life.

(b) When establishing WQBELs in permits the department shall assume that the pollutant of concern does not degrade over time unless any the following conditions are met:

1. Scientifically valid field studies or other relevant information demonstrate that degradation of the pollutant is expected to occur under the full range of environmental conditions expected.

2. Scientifically valid field studies or other relevant information address other factors that affect the level of pollutants in the water column including suspension of sediments, chemical speciation, and biological and chemical transformation.

(3)   Mixing zones for bioaccumulative chemicals of concern (BCCs). WQBELs derived from TMDL wasteload allocations for BCCs shall be consistent with and no less stringent than the mixing zone provisions under s. NR 106.06 (2) .

(4)   Expression of limits. WQBELs derived from TMDL wasteload allocations shall be expressed consistent with the provisions specified in s. NR 205.065 unless impracticable or an alternative expression of limitations is determined appropriate by the department and is consistent with the assumptions of the TMDL.

(5)   Compliance schedules. When a permit is issued, reissued, or modified with new WQBELs based on a TMDL established using the procedures in this subchapter, the department may include a compliance schedule to achieve compliance with the TMDL based limitation if the permittee's treatment system is unable to immediately comply with the limitation. The compliance schedule shall meet all of the following conditions:

(a) The schedule of compliance will lead to compliance with the water quality based effluent limitation as soon as possible.

(b) The compliance schedule may not extend beyond the expiration date of the permit unless extended compliance schedules are authorized in ch. NR 217 , other Wisconsin administrative code chapters, or a TMDL schedule in an approved areawide water quality management plan under ch. NR 121 . Compliance schedules for toxic and organoleptic substances shall be consistent with the requirements of s. NR 106.117 .

(c) Dates between interim compliance steps in the compliance schedule may not exceed one year.

(d) Development and implementation of an optimization plan or pollution minimization plan may be included as part of the compliance schedule as a means of complying with the effluent limitation.

(6)   Relationship of WQBELS derived from TMDL wasteload allocations and other wqbels. The department may include WQBELs derived from TMDL wasteload allocations in a permit in addition to, or in lieu of, other WQBELs.

History: CR 15-085 : cr. Register August 2016 No. 728 , eff. 9-1-16.