(a) Written approval of a SWM Site Plan must be issued by the Municipality prior to commencement of regulated activities unless exempt from this requirement under Section 1488.10.
(b) SWM Site Plans approved by the Municipality shall be on-site throughout the duration of the regulated activity.
(c) The Municipality may, after consultation with the PA DEP, approve measures for meeting the State Water Quality Requirements other than those in this chapter, provided they meet the minimum requirements of, and do not conflict with, State law including but not limited to the Clean Streams Law.
(d) For all regulated activities, implementation of peak rate controls and preparation of a SWM Site Plan are required, unless exempted by Section 1488.10.
(e) Impervious Areas.
(1) The measurement of impervious areas shall include all of the impervious areas in the total proposed development even if development is to take place in stages.
(2) For development taking place in stages, the entire development plan must be used in determining conformance with this chapter.
(3) For projects that add impervious area to a parcel, the total impervious area on the parcel is subject to the requirements of this chapter, unless, the project is otherwise deemed exempt from storm water management provisions per the criteria set forth in Section 1488.09.
(4) Existing gravel parking areas, driveways, and roads shall not be considered impervious. These areas shall be treated as semi-pervious and shall be analyzed using the appropriate SCS curve number based on the appropriate HSG underlying the gravel areas, which is defined as:
A. HSG A. Gravel area curve number shall be 76.
B. HSG B. Gravel area curve number shall be 85.
C. HSG C. Gravel area curve number shall be 89.
D. HSG D. Gravel area curve number shall be 91.
(5) Proposed gravel parking areas, driveways, and roads shall be considered impervious.
(f) Storm water discharges onto adjacent property shall not be created, increased, decreased, or relocated, or otherwise altered without [permission|written notification] of adjacent property owner(s). Such discharges shall be subject to the requirements of this chapter.
(g) All regulated activities shall include such measures as necessary to:
(1) Protect health, safety, and property;
(2) Meet the water quality goals of this chapter by implementing measures to:
A. Minimize disturbance to floodplains, wetlands, natural slopes over 15%, and existing native vegetation.
B. Minimize thermal impacts to waters of the Commonwealth.
C. Preserve and maintain trees and woodlands. Maintain or extend riparian buffers and protect existing forested buffer. Provide trees and woodlands adjacent to impervious areas.
D. Establish and maintain non-erosive flow conditions in natural flow pathways.
E. Minimize soil disturbance and soil compaction. Cover disturbed areas with topsoil having a minimum depth of four inches. Use tracked equipment for grading.
F. Disconnect impervious surfaces by directing runoff to pervious areas.
(3) Incorporate the techniques described in the Appendices attached to Ordinance 2458 whenever practical.
(h) The design of all facilities over Karst shall include an evaluation of measures to minimize adverse effects.
(i) Infiltration BMPs shall be spread out, made as shallow as practicable, and located to maximize use of natural on-site infiltration features while still meeting the other requirements of this chapter.
(j) Storage facilities shall completely drain both the volume control and rate control capacities over a period of time not less than 24 and not more than 72 hours from the end of the design storm.
(k) The design storm volumes to be used in the analysis of peak discharge rates shall be obtained from the Precipitation-Frequency Atlas of the United States, Atlas 14, Volume 2, U.S. Department of Commerce, National Oceanic and Atmospheric Administration, National Weather Service, Hydrometeorological Design Studies Center, Silver Spring, Maryland, 20910. NOAA's Atlas 14 can be accessed at Internet address:
(l) The Municipality and its engineer may require that regulated activities maintain a minimum distance between proposed impervious areas/storm water management facility outlets and down slope property line(s).
(m) SWM BMPs for all regulated activities shall be designed, implemented, operated, and maintained to meet the purposes and requirements of this chapter and to meet all requirements under Title 25 of the Pennsylvania Code, the Clean Streams Law, and the Storm Water Management Act.
(n) For all regulated earth-disturbance activities, erosion and sediment control BMPs shall be designed, implemented, operated, and maintained during the regulated earth- disturbance activities (e.g., during construction) to meet the purposes and requirements of this chapter and to meet all requirements under Title 25 of the Pennsylvania Code and the Clean Streams Law. Various BMPs and their design standards are listed in the Erosion and Sediment Pollution Control Program Manual/(E&S Manual), No. 363-2134-008 (April 15, 2000), as amended and updated.
(Ord. 2458. Passed 11-15-10.)