(a) For all regulated activities, unless preparation of an SWM Site Plan is specifically exempted in § 1393.02:
(1) Preparation and implementation of an approved SWM Site Plan is required; and
(2) No regulated activities shall commence until the City of Williamsport issues written approval of an SWM Site Plan, which demonstrates compliance with the requirements of this title.
(b) SWM Site Plans approved by the City of Williamsport, in accordance with § 1394.06, shall be on site throughout the duration of the regulated activity.
(c) The City of Williamsport may, after consultation with DEP, approve measures for meeting the state water quality requirements other than those in this title; provided that, they meet the minimum requirements of, and do not conflict with, state law including, but not limited to, the Clean Streams Law.
(e) 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 title 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, as amended and updated.
(f) 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 title.
(3) For projects that add impervious area to a parcel, the total impervious area on the parcel is subject to the requirements of this title; except that the volume controls in § 1393.03 and the peak rate controls of § 1393.04 do not need to be retrofitted to existing impervious areas that are not being altered by the proposed regulated activity.
(g) Storm water flows onto adjacent property shall not be created, increased, decreased, relocated or otherwise altered without written notification to and formal concurrence from the adjacent property owner(s). Such storm water flows shall be subject to the requirements of this title.
(h) All regulated activities shall include such measures as necessary to:
(1) Protect health safety, and property;
(2) Meet state water quality requirements as defined in Art. 1392;
(3) Meet the water quality goals of this title by implementing measures to:
(A) Minimize disturbance to floodplains, wetlands, and wooded areas;
(B) Preserve and maintain trees and woodlands. Maintain or extend riparian buffers and protect existing forested buffers. Provide trees and woodlands adjacent to impervious areas whenever feasible;
(C) Avoid erosive flow conditions in natural flow pathways;
(D) Minimize soil disturbance and soil compaction. Cover disturbed areas and replace topsoil to a depth sufficient to achieve vegetated cover or four inches, whichever is greater. Use tracked equipment for grading when feasible;
(E) Minimize thermal impacts to waters of this Commonwealth; and
(F) Disconnect impervious surfaces by directing runoff to pervious areas, wherever possible.
(4) Incorporate methods described in the Pennsylvania Storm water Best Management Practices Manual (PA BMP Manual).
(i) The design of all facilities over karst shall include an evaluation of measures to minimize adverse effects.
(j) Infiltration BMPs should 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 Title.
(k) Normally dry, open top, storage facilities should 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.
(l) The design storm volumes to be used in the analysis of peak rates of discharge should be obtained from the latest version of the Precipitation-Frequency Atlas of the United States, National Oceanic and Atmospheric Administration (NOAA). National Weather Service, Hydrometeorological Design Studies Center. Silver Spring, Maryland. NOAA/s Atlas 146 can be accessed at http://hdsc.nws.noaa.gov/hdsc/pfds/.
(m) For all regulated activities, SWM BMPs shall be designed, implemented, operated and maintained to meet the purposes and requirements of this title and to meet all requirements under Title 25 of the Pennsylvania Code, the Clean Streams Law, and the Storm Water Management Act.
(n) Various BMPs and their design standards are listed in the BMP Manual.
(o) All materials, workmanship and methods of work shall comply with the Pennsylvania Department of Transportation (PA DOT) Publication 408 Specifications, as accepted and commonly used by the City of Williamsport, and shall be considered to be incorporated into this article as if copied in full. In the event a conflict arises between the requirements of this Title and the PA DOT Publication 408 Specifications, the City of Williamsport shall resolve the difference, and said opinion shall be binding.
(p) Supplemental standards and criteria contained in Art. 1399 are hereby incorporated into this title to govern the hydrologic and hydraulic design provisions contained herein.
(q) The signature and seal of a registered professional engineer, if required, must be provided at the time of plan submission.
(Ord. 6211, approved 4-15-2012; Ord. 6481, approved 3-14-2024)