(A) All sites shall develop a stormwater pollution prevention plan. The plan must include: a description of potential pollutant sources from the proposed land use, that may reasonably be expected to add a significant amount of pollutants to stormwater discharge; location, dimensions, detailed specifications, and construction details of all post construction stormwater quality measures; a description of measures that will be installed to control pollutants in stormwater discharges that will occur after construction activities have been completed; a sequence describing when each post construction stormwater quality measure will be installed; and a narrative description of the maintenance guidelines for all post construction stormwater quality measures to facilitate their proper long term function.
(B) All site designs shall establish stormwater management practices to control the peak flow rates of stormwater discharge associated with specified design storms and reduce the generation of stormwater. These practices should seek to utilize swales and natural depressions as site conditions allow, utilize pervious areas for stormwater treatment and to infiltrate stormwater runoff generated from driveways, sidewalks, rooftops, parking lots, and landscaped areas to the maximum extent practical to provide treatment for both water quality and quantity.
(C) All stormwater runoff generated from new development shall not discharge untreated stormwater directly into a jurisdictional wetland or local water body without adequate treatment. Where such discharges are proposed, the impact of the proposal on wetland functional values shall be assessed using a method acceptable to the city. In no case shall the impact on functional values be any less than allowed by the Army Corp of Engineers (ACE) or the Indiana Department of Natural Resources (IDNR).
(D) All sites shall preserve buffer strips and riparian zones, create filter strips, minimize land disturbance, minimize surface imperviousness, minimize directly connected impervious areas, maximize open space, direct growth away from sensitive areas and toward areas that can support it without compromising water quality, have storage, have infiltration, in any combination, where appropriate to reduce the impact of pollutants in stormwater runoff on receiving waters.
(E) Infiltration practices will not be allowed in wellhead protection areas.
(F) Discharges from an MS4 area will not be allowed directly into sinkholes or fractured bedrock without treatment that results in the discharge meeting Indiana ground water quality standards as referenced in 327 IAC 2-11.
(G) Any stormwater practice that is a Class V injection well must ensure that the discharge from such practices meets Indiana ground water quality standards as referenced in 327 IAC 2-11.
(H) As site conditions allow, the rate at which water flows through the MS4 conveyances shall be regulated to reduce outfall scouring and stream bank erosion. Where necessary, channel protection shall be provided to protect stream channels from degradation.
(I) As site conditions allow, a vegetated filter strip of appropriate width shall be maintained along unvegetated swales and ditches.
(J) New retail gasoline outlets, new municipal, state, federal, or institutional refueling areas, or outlets and refueling areas that replace their existing tank systems shall be required to design and install appropriate practices to reduce lead, copper, zinc, and polyaromatic hydrocarbons in stormwater runoff.
(K) Stormwater discharges to critical areas with sensitive resources (i.e., wellhead protection areas, cold water fisheries, shellfish beds, swimming beaches, recreational waters, recharge areas, water supply reservoirs) may be subject to additional performance criteria, or may need to utilize or restrict certain stormwater management practices.
(L) Certain industrial sites are required to prepare and implement a stormwater pollution prevention plan in accordance with 327 IAC 15-6, and shall file a notice of intent (NOI) under the provisions of the National Pollutant Discharge Elimination System (NPDES) general permit. The stormwater pollution prevention plan requirement applies to both existing and new industrial sites.
(M) Stormwater discharges from land uses or activities with higher potential pollutant loadings, known as "hotspots", may require the use of specific structural stormwater treatment practices and pollution prevention practices.
(Ord. 2005-30, passed 8-23-2005)