Current through August 26, 2024
(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.
