Current through 2024-38, September 18, 2024
An owner or operator of property in an urban impaired stream
watershed that has been designated by the U.S. Environmental Protection Agency
pursuant to the Clean Water Act,
33 U.S.C.
§§1251 et seq., and
40
C.F.R.
§122.26(a)(9)(i)(D), or
the Department pursuant to Chapter 521(9)(a)(1)(v), as requiring a storm water
discharge permit due to post-construction storm water flow from impervious
area, shall either provide a notice of intent to comply with a general permit
adopted pursuant to Chapter 529, if available, or shall apply for an individual
permit.
(a) Individual permit
requirements. To qualify for an individual permit, the following requirements
must be met in addition to otherwise applicable requirements.
(1) The basic standards described in the
Department's Stormwater Management Rules, Chapter 500, Section 4(A), addressing
erosion and sedimentation control, inspection and maintenance, and housekeeping
must be met.
(2) Provisions for
treatment of stormwater from the impervious area of the property must be
provided that comply with the general standards described in the Department's
Stormwater Management Rules, Chapter 500, Section 4(B), with no exception for a
linear portion of a project. If on-site conditions make storm water treatment
on the operator's site impracticable, off-site treatment may be approved if
located in the same watershed. If provisions for treatment of storm water
meeting these standards are not in place at the time of application, then the
application must include plans for storm water treatment measures that will be
put in place within two years of permit issuance. The Department may extend the
two-year period up to five years if the parcel includes five acres or more of
impervious area and interim milestones are approved.
(3) Inspections of best management practices
must occur at least annually by a qualified person to determine if they are in
place and functioning as intended, and if not, corrective action must be taken
within 30 days. Maintenance plans for the property must include provisions for
sweeping paved areas at least once per year after snowmelt.
(4) An on-going monitoring program must be
established, either by measuring the water quality of storm water discharge
from the project site for parameters and at a frequency approved by the
Department, or by contributing to a Department-approved monitoring program, at
a rate consistent with assessments to other participants of a
Department-approved watershed management plan for monitoring work.
(b) Stream restoration. When the
stream channel or riparian area has been impacted due to storm water flow from
the applicant's impervious area, the Department may require the following:
(1) Measures be taken to mitigate the effects
of the past storm water discharges from the applicant's property on the urban
impaired stream, such as restoration of floodplain area, establishment of
vegetated riparian buffers, and stabilization of the stream channel. Where the
adverse effect to be mitigated is the result of discharges from the property of
applicant in combination with discharges from other property, then the
mitigation required will be in proportion to the estimated discharge from the
applicant's property in relation to the amount of contributing discharge from
other properties; or
(2) Where a
Department-approved watershed management plan exists and is being implemented,
a financial contribution, or a combination of a financial contribution and
mitigation toward restoration of floodplain area, establishment of vegetated
riparian buffers, and stabilization of the stream channel, consistent with the
approved watershed management plan. The financial contribution must be based on
the amount of impact caused by the operator's past discharges where this can be
assessed, Otherwise, payment may be based on the percentage of impervious area
in the watershed that is located on the applicant's property, multiplied by the
estimated total cost for stream channel restoration. Payments may be spread
over multiple years in accordance with a schedule approved by the Department,
and must be utilized for specific mitigation work identified in the watershed
plan.
(c) Credit for
watershed plan contributions. The Department may allow an applicant to reduce
the amount of treatment for impervious area required in section 9-A(a) by
giving credit for prior contributions toward implementation of a
Department-approved watershed management plan. The amount of credit given is
determined by the department on a case-by-case basis.
(d) Additional requirements. The Department
may establish additional on-site mitigation and stream restoration
requirements, if necessary, to ensure progress in restoring water quality in
the impaired stream.
