(1) GENERAL.
(a) An owner or operator of a permitted
wastewater treatment system that consists primarily of a stabilization pond
system or a lagoon system may apply for a variance to the phosphorus water
quality based effluent limitations pursuant to s. 283.15(4) (a)
1 f., Stats., using the procedures in this
section.
Note: Stabilization ponds and lagoons are operated
primarily by communities serving a population of 2000 or less and small
industries. With currently available technology that could be used in
conjunction with stabilization ponds or lagoons, it is unlikely that phosphorus
water quality based effluent limits less than 1 mg/L can be consistently met.
To meet phosphorus water quality based effluent limits of less than 1 mg/L, it
will be necessary for owners of the systems to construct new wastewater
treatment plants which could result in substantial and widespread adverse
social and economic impacts.
(b) A new discharger may not receive approval
for a variance under this section or pursuant to any other variance
procedure.
(2)
APPLICATION FOR A VARIANCE.
(a) The
application for a variance under this section shall be submitted with the WPDES
permit application for reissuance, or within 30 days after the permittee
receives written notification of the proposed phosphorus limits, if the
notification occurs later. The application shall be submitted on the phosphorus
lagoon and stabilization pond variance form made available from the department
or on a form containing equivalent information.
Note: Owners or operators of stabilization ponds or lagoon
systems may obtain the variance application form from the offices of the
department of natural resources, bureau of watershed management at 101 South
Webster Street, P.O. Box 7921, Madison, Wisconsin 53707. The form will provide
guidance on the type of information needed to demonstrate widespread social and
economic impacts.
(b) The
application shall, at a minimum, include the following information:
1. Information required by s.
NR 200.22, except for the information in s.
NR 200.22(1) (e) 6.
2. A statement that the permittee is seeking
a variance pursuant to this section and s. 283.15(4) (a)
1 f., Stats.
3. Information on the number and volume of
lagoon or pond treatment cells, treatment processes, discharge periods,
retention times, population served, influent flow, and available capacity for
holding wastewater.
4. Other
information requested by the department that is relevant to the review
conducted under sub. (3).
Note: It is recommended that the permittee ask for
calculation of potential phosphorus water quality based limits at least 12
months prior to permit expiration. This information will help the permittee
complete their variance request portion of the permit application which is due
180 days prior to permit expiration.
(3) DEPARTMENT REVIEW.
(a) The department shall review the submitted
application for the variance and determine whether the permittee can achieve
the phosphorus effluent limitations calculated pursuant to s.
NR 217.13 with out widespread adverse social and economic
impacts. In making this determination, the department shall:
1. Compare the calculated phosphorus effluent
limitations to the phosphorus effluent data submitted under sub. (2). If the
permittee does not have sufficient phosphorus discharge data for its system,
the department may augment the data set with effluent data from a similar
lagoon or pond system in the state to make the comparison. The department may
apply statistical methodologies to make its determination on the ability of the
current lagoon or stabilization pond system to meet phosphorus
limitations.
2. Evaluate the
financial affordability analysis submitted by the permittee in response to the
variance application requirement in s.
NR 200.22(1) (p).
Note: The department may use a US EPA publication titled,
Interim Economic Guidance for Water Quality Standards - Workbook,
EPA-823-B-95-002, March 1995, which provides information on evaluating economic
and social impacts.
(b) The department's decision to approve or
deny a variance under this section shall be made on or before the date of the
s.
283.53(3) (d), Stats., public notice for the proposed
permit reissuance and shall be made in accordance with the following:
1. If the department determines that the
permittee cannot meet the phosphorus water quality based effluent limitation
without widespread adverse social and economic impacts, the department shall
approve the variance. If the variance is approved, the department shall specify
in the permit that the variance has been granted for phosphorus, and the
requirements in sub. (4) shall also be included in the permit.
2. If the department determines that the
permittee can meet the phosphorus effluent limitations without widespread
adverse social and economic impacts or that effluent limitations are not
necessary as determined by s.
NR 217.15, the department shall deny the variance and
notify the applicant of this determination in writing.
(c) If the department denies a variance under
this section, a permittee may not apply again after the permit is issued for a
variance from the phosphorus water quality standard based on the factor in s. 283.15(4) (a)
1 f., Stats., for the same permit
term.
(d) A permittee may seek a
variance from a phosphorus limit in a reissued WPDES permit based on the
factors in s. 283.15(4) (a)
1 a. to e., Stats., and using the procedures
and requirements in s.
283.15,
Stats., and ch. NR 200.
Note: All variances are subject to US EPA review and
approval.
(4)
PERMIT TERMS IF VARIANCE IS APPROVED. If the department approves a variance to
the phosphorus effluent limitations under this section, the following
requirements shall be included in the reissued permit:
(a) The permit shall include a phosphorus
variance effluent limitation as follows:
1.
The numeric limitation shall equal the upper 99th percentile of representative
daily discharge concentrations (one-day P99) as calculated in s.
NR 106.05(5) (a).
2. The variance limitation shall be expressed
as a daily maximum concentration.
(b) The permittee shall conduct monitoring of
phosphorus during discharge periods at a frequency specified in the
permit.
(c) The permittee shall, to
the extent practicable, identify and minimize the non-domestic sources of
phosphorus to the system and operate the treatment system to minimize
exceedances of the calculated limits.
(d) The permittee shall investigate treatment
technologies, process changes, pollutant source reduction steps, wastewater
reuse or other techniques that may result in compliance by the permittee with
the applicable phosphorus water quality standard, and shall submit reports on
those investigations as required by the department.
(5) CONTINUED VARIANCES. If a permittee
received approval for a variance to the phosphorus standard under this section
in a reissued permit, the permittee may request a continued variance from the
phosphorus standard in a subsequent reissued permit pursuant to the procedures
and requirements in this section.
