The purpose of this subchapter is to provide for the health, safety, and general welfare of the citizens of the village through the regulation of stormwater and nonstormwater discharges to the storm drainage system to the maximum extent practicable as required by Federal and state law. This subchapter establishes methods for controlling the introduction of pollutants into the municipal separate storm sewer system (MS4) in order to comply with requirements of the National Pollutant Discharge Elimination System (NPDES) permit process. The objectives of this subchapter are:
(A) To regulate the contribution of pollutants to the municipal separate storm sewer system (MS4) by stormwater discharges by any user.
(B) To prohibit illicit connections and discharges to the municipal separate storm sewer system.
(C) To establish legal authority to carry out all inspection, surveillance, and monitoring procedures necessary to ensure compliance with this subchapter.
(D) As a requirement of the NPDES stormwater discharge permit and the village's municipal separate storm sewer system permit, the village accepts the following Oakland County Standards for Post-Construction Storm Water Runoff:
(1) The Oakland County Post-Construction Storm Water Runoff Program including the Oakland County Stormwater Engineering Design Standards as amended from time to time, is hereby adopted by the Village of Lake Orion in this section for the control and treatment of stormwater runoff with the exception that all developments subject to this section shall provide acceptable water quality treatment BMPs designed to achieve 80% removal efficiency of total suspended solids from the runoff produced by a one-inch rainfall event.
(2) The property owner, upon completion of construction, must enter into a binding long-term maintenance agreement with the village, at their own expense, to document, routinely monitor and maintain the stormwater quantity and quality BMPs so they continue to operate as designed. The agreement shall be set up that if the property owner should be determined to be non-responsive to a notice of required maintenance actions, that the village may enter the property to perform the maintenance required.
(3) These standards shall apply to address post-construction storm water runoff from new development and redevelopment projects that disturb one or more acres, including projects less than one acre that are part of a larger common plan of development or sale, and that discharge into the village's MS4.
(4) All permanent and temporary stormwater management BMPs, constructed as part of the requirements of this section, are subject to this section.
(5) This section also applies to any activities which may affect the quantity or quality of a private or stormwater conveyance system or any waterway within the village. Any person(s) engaged in activities that may result in excessive quantities or pollutants entering any stormwater conveyance systems or waterways may be subject to the remedies for violation of this section. Examples of such pollutants may include, but is not limited to, debris, concrete washings, deicing materials, fertilizers, heavy metals, automobile fluids, topsoil, yard wastes, and commercial or light industrial wastes.
(6) Natural swales and channels should be preserved, whenever possible. If channel modification must occur, the physical characteristics of the modified channel will meet the existing channel in length, cross-section, slope, sinuosity, and carrying capacity. Streams and channels will be expected to withstand all events up to the two-year storm without increased erosion.
(7) Channel Protection Volume Control (CPVC) must retain onsite the post-development runoff volume from a 1.3-inch rainfall event. Provide infiltration and/or storage/reuse BMPs to the Maximum Extent Possible (MEP).
(8) Channel Protection Rate Control (CPRC) must provide extended detention for the post-development runoff volume from a 1.9-inch rainfall event.
(9) All structural and vegetative BMPs must be installed and implemented to meet the performance standards shall be operated and maintained in perpetuity. The permittee shall implement and enforce the ordinance or regulatory mechanism program to ensure long-term operation and maintenance of BMPs.
(10) The regulatory mechanism and procedures for site plan approval and the Design and Construction Standards shall apply for projects that disturb one or more acres, including projects less than one acre that are part of a larger common plan of development or sale, and discharge to the permittee's MS4, including projects where the permittee is the developer. The final site plan review and approval shall demonstrate compliance with the performance standards and long-term operation and maintenance requirements stated in this subchapter.
(Ord. 23.35, passed 2-8-16; Am. Ord. 23.29, passed 4-25-22)