Mont. Admin. R. 17.30.1105 - PERMIT REQUIREMENT

(1) On or after October 1, 1994, operators must obtain an MPDES permit for discharges composed entirely of storm water that are not required by (4) to obtain a permit only if:

(a) the discharge is associated with small construction activity as defined in ARM 17.30.1102;

(b) the discharge is from a small municipal separate storm sewer system as defined in ARM 17.30.1102 or as designated pursuant to ARM 17.30.1107;

(c) the department determines that storm water controls are needed based on wasteload allocations that are part of TMDLs that address the pollutants of concern; or

(d) the department determines that the discharge is contributing to a violation of a water quality standard or is a significant contributor of pollutants to surface waters.

(2) Any person who discharges or proposes to discharge storm water combined with municipal sewage from a point source shall obtain MPDES permits in accordance with the procedures set out in ARM Title 17, chapter 30, subchapter 13 and is not subject to the provisions of this subchapter.

(3) The department may waive the permit requirements in this subchapter for a storm water discharge associated with construction activity that disturbs less than five acres of total land area if either of the following two conditions exist:

(a) the value of the rainfall erosivity factor ("R" in the revised universal soil loss equation) is less than five during the period of construction activity. The rainfall erosivity factor must be determined using a state-approved method. The owner or operator must certify to the department that the construction activity will take place only during a period when the value of the rainfall erosivity factor is less than five. If unforeseeable conditions occur that are outside of the control of the waiver applicant, and which will extend the construction activity beyond the dates initially applied for, the owner or operator shall reapply for the waiver or obtain authorization under the general permit for storm water discharges associated with construction activity. The waiver reapplication or notice of intent must be submitted within two business days after the unforeseeable condition becomes known; or

(b) storm water controls are not needed based on a TMDL approved or established by EPA that addresses the pollutants of concern or, for non-impaired waters that do not require TMDLs, an equivalent analysis that determines allocations for construction sites disturbing less than five acres of total land area for the pollutants of concern or that determines that such allocations are not needed to protect water quality based on consideration of existing in-stream concentrations, expected growth in pollutant contributions from all sources, and a margin of safety. For the purposes of this rule, pollutants of concern include sediment, or a parameter that addresses sediment (such as total suspended solids, turbidity or siltation) , and any other pollutant that has been identified as a cause of impairment of any water body that will receive a discharge from the construction activity. The operator shall certify to the department that the construction activity will take place, and that storm water discharges will occur, within the drainage area addressed by the TMDL or equivalent analysis.

(4) Prior to October 1, 1994, discharges composed entirely of storm water are not required to obtain an MPDES permit except for:

(a) discharges with respect to which an MPDES permit has been issued prior to February 4, 1987;

(b) a discharge associated with an industrial activity; or

(c) a discharge that the department or EPA regional administrator determines contributes to a violation of a water quality standard or is a significant contributor of pollutants to state waters.

(5) For storm water discharges designated by the department under (1) (e) and (f) , the owner or operator shall apply for a permit within 180 days of receipt of the department's notice of designation, unless the department grants a later date.

(5) For storm water discharges designated by the department under (1) (c) and (d) or (4)(c), the owner or operator shall apply for a permit within 180 days of receipt of the department's notice of designation, unless the department grants a later date.

(6) Except as provided in (7), any storm water discharge associated with an industrial activity as defined in ARM 17.30.1102 that is not covered under an existing MPDES permit must submit a permit application to the department by October 1, 1992.

(7) The permit requirements in this subchapter are effective beginning March 10, 2003, for any storm water discharge associated with industrial activity from a facility that is owned or operated by a municipality with a population of under 100,000 that is not authorized by a general or individual permit, other than an airport, powerplant, or uncontrolled sanitary landfill.

(8) The eligibility of an owner or operator of a discharge from an MS4 for funding under Title II, Title III, or Title VI of the federal Clean Water Act shall not be affected by the regulation or nonregulation of the MS4 under this subchapter.

(9) A person may petition the department to require an MPDES permit for a discharge that is composed entirely of storm water that contributes to a violation of a water quality standard or is a significant contributor of pollutants to surface waters.

Notes

Mont. Admin. R. 17.30.1105

NEW, 2003 MAR p. 219, Eff. 2/14/03; AMD, 2014 MAR p. 3056, Eff. 12/25/2014.

75-5-201, 75-5-401, MCA; IMP: 75-5-401, MCA;