A. 
No regulated activities shall commence until the municipality approves a plan, which demonstrates compliance with the requirements of this chapter.
B. 
Plans approved by the municipality shall be on site throughout the duration of the regulated activity.
C. 
The municipality may, after consultation with DEP, approve alternative methods for meeting the state water quality requirements other than those in this chapter, provided that 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 equal to or greater than 1,000 square feet in area, implementation of peak rate controls and preparation of a SWM site plan are required, unless exempted by § 253-9 of this chapter. Please note that a predesign conference is recommended to discuss the design and implementation of peak rate controls, and the preparation of a SWM site plan. Also note that both the applicant and the qualified professional must attend this predesign conference.
E. 
Impervious areas.
(1) 
The measurement of impervious areas shall include the all of the imperious 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 subsequent to enactment of this chapter, the total impervious area on the parcel, created subsequent to enactment of this chapter, shall be subject to the requirements of this chapter.[1]
[1]
Editor's Note: Amended at time of adoption of Code (see Ch. 1, General Provisions, Art. I).
F. 
Discharges onto adjacent property shall not be created, increased, relocated, decreased, or relocated, or otherwise altered without permission of the adjacent property owner(s) unless it is determined by Borough Council, after consultation/review or recommendation by the Borough Engineer that such discharges do not adversely affect the adjacent property, taking into consideration the intent and the requirements of this chapter. Such discharges shall otherwise be subject to all the requirements contained in of this chapter.
G. 
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 Article II;
(3) 
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) 
Preserve and maintain trees and woodlands. Maintain or extend riparian buffers and protect existing forested buffer. Provide trees and woodlands adjacent to impervious areas whenever feasible.
(c) 
Establish and maintain nonerosive flow conditions in natural flow pathways.
(d) 
Minimize soil disturbance and soil compaction. Cover disturbed areas with topsoil having a minimum depth of four inches. Use tracked equipment for grading when feasible.
(e) 
Disconnect impervious surfaces by directing runoff to pervious areas.
(4) 
Incorporate the techniques described in Appendix D of this chapter (Low Impact Development Practices) whenever practical.[2]
[2]
Editor's Note: Appendix D is included at the end of this chapter.
H. 
The design of all facilities over Karst shall include an evaluation of measures to minimize adverse effects.
I. 
The design storm volumes to be used in the analysis of peak rates of discharge should 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: http://hdsc.nws.noaa.gov/hdsc/pfds/.
J. 
All project sites shall be evaluated for the presence of wetlands. If wetlands are present, then the applicant shall obtain a jurisdictional determination from the USACE.
A. 
Regulated activities that create disconnected impervious areas smaller than 400 square feet are exempt from the peak rate control and the SWM site plan preparation requirement of this chapter.
B. 
Regulated Activities that create disconnected impervious areas equal to or greater 400 square feet and less than 1,200 square feet are exempt only from the peak rate control requirement of this chapter.
C. 
Agricultural plowing and tilling are exempt from the rate control and SWM site plan preparation requirements of this chapter provided the activities are performed according to the requirements of 25 Pa. Code, Chapter 102.
D. 
Forest management and timber operations are exempt from the rate control and SWM site plan preparation requirements of this chapter provided the activities are performed according to the requirements of 25 Pa. Code, Chapter 102.
E. 
Exemptions from any provisions of this chapter shall not relieve the applicant from the requirements in § 253-8F, G, H, and J.
The low-impact development practices provided in the SWM Manual[1] shall be utilized for all regulated activities to the maximum extent practicable.
A. 
Areas tributary to high-quality or exceptional-value waters. All regulated activities occurring in drainage areas tributary to waters designated high quality or exceptional value pursuant to 25 Pa. Code, Chapter 93, shall not change any biological, chemical, or physical characteristic, including volume, rate, velocity, course, current, cross-section, or temperature of the waters, unless the activity is specifically permitted in accordance with the environmental laws of this commonwealth.
B. 
Areas not tributary to high quality or exceptional value waters. For regulated activities in drainage areas that are not tributary to special protection waters, water quality controls shall be implemented using the design storm method in Subsection B(1) or the simplified method in Subsection B(2) below. For regulated activity areas equal or less than one acre that do not require hydrologic routing to design the stormwater facilities, this chapter establishes no preference for either methodology; therefore, the applicant may select either methodology on the basis of economic considerations, the intrinsic limitations on applicability of the analytical procedures associated with each methodology, and other factors.
(1) 
The design storm method (CG-1 in the SWM Manual[2]) is applicable to any size of regulated activity. This method requires detailed modeling based on site conditions.
(a) 
Do not increase the postdevelopment total runoff volume for all storms equal to or less than the two-year twenty-four-hour duration precipitation.
(b) 
For modeling purposes:
[1] 
Existing (predevelopment) nonforested pervious areas must be considered meadow or its equivalent.
[2]
Editor's Note: See Reference 1 in Appendix E, which is included at the end of this chapter.
(2) 
The simplified method (CG-2 in the SWM Manual[3]) provided below is independent of site conditions and should be used if the design storm method is not followed. This method is not applicable to regulated activities greater than one acre or for projects that require detailed design of stormwater storage facilities. For new impervious surfaces:
(a) 
Stormwater facilities shall capture at least the first two inches of runoff from all new impervious surfaces.
(b) 
At least the first one inch of runoff from new impervious surfaces shall be permanently removed from the runoff flow; i.e., it shall not be released into the surface waters of this commonwealth. Removal options include reuse, evaporation, transpiration, and infiltration.
(c) 
Wherever possible, infiltration facilities should be designed to accommodate infiltration of the entire permanently removed runoff; however, in all cases at least the first 0.5 inch of the permanently removed runoff should be infiltrated.
(d) 
This method is exempt from the requirements of § 253-11, Rate controls.
[3]
Editor's Note: See Reference 1 in Appendix E, which is included at the end of this chapter.
[1]
Editor's Note: See Reference 1 in Appendix E, which is included at the end of this chapter.
A. 
Areas not covered by a release rate map from an approved Act 167 Stormwater Management Plan. Postdevelopment discharge rates shall not exceed the predevelopment discharge rates for the two-, ten-, fifty-, and one-hundred-year storms. If it is shown that the peak rates of discharge indicated by the postdevelopment analysis are less than or equal to the peak rates of discharge indicated by the predevelopment analysis for two-, ten-, twenty-five-, and one-hundred-year, twenty-four-hour storms, then the requirements of this section have been met. Otherwise, the applicant shall provide additional controls as necessary to satisfy the peak rate of discharge requirement.
B. 
Areas covered by a release rate map from an approved Act 167 Stormwater Management Plan. For the two-, ten-, twenty-five-, and one-hundred-year storms, the postdevelopment peak discharge rates will follow the applicable approved release rate map. For any areas not shown on the release rate map, the postdevelopment discharge rates shall not exceed the predevelopment discharge rates.
C. 
BMPs for rate controls. A list of BMPs for peak rate controls is provided in Appendix C, Item C.[1]
[1]
Editor's Note: Appendix C is included at the end of this chapter.