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(A) Under no circumstance shall the applicant be exempt from implementing such measures as necessary to:
(1) Meet state water quality standards and requirements;
(2) Protect health, safety and property; or
(3) Meet special requirements for high quality (HQ) and exceptional value (EV) watersheds.
(B) The applicant must utilize the following BMPs to the maximum extent practicable to receive consideration for the exemptions:
(1) Design around and limit disturbance of floodplains, wetlands, natural slopes over 15%, existing native vegetation and other sensitive and special value features;
(2) Maintain riparian and forested buffers;
(3) Limit grading and maintain non-erosive flow conditions in natural flow paths;
(4) Maintain existing tree canopies near impervious areas;
(5) Minimize soil disturbance and reclaim disturbed areas with topsoil and vegetation; and
(6) Direct runoff to pervious areas.
(C) The applicant’s proposed development/additional impervious area may not adversely impact the following:
(1) Capacities of existing drainageways and storm sewer systems;
(2) Velocities and erosion;
(3) Quality of runoff if direct discharge is proposed;
(4) Existing known problem areas;
(5) Safe conveyance of the additional runoff; and/or
(6) Downstream property owners.
(D) An applicant proposing regulated activities, after demonstrating compliance with divisions (A) through (C) above may be exempted from various requirements of this chapter according to the following table.
New Impervious Area (Square Footage) 1,2 | Applicant Must Provide |
New Impervious Area (Square Footage) 1,2 | Applicant Must Provide |
0-1,000 | - |
1,000-2,500 | Documentation of impervious area 3 |
2,500-5,000 | Volume controls and small project SWM application |
> 5,000 | Rate controls, volume controls and SWM Site Plan |
Notes: | |
(1)New impervious area since the date of adoption of this chapter. | |
(2)Gravel in existing condition shall be considered pervious and gravel in proposed condition shall be considered impervious. | |
(3)The small project stormwater management application included in Appendix E may be used for projects under 5,000 square feet of new impervious surface and single-family home construction. The small project SWM application allows documentation of new impervious surface, credits through disconnection of impervious surfaces and free planting, and sizing of volume control BMPs that may be required. | |
(E) Single-family residential activities are exempt from these requirements provided the construction:
(1) Comply with § 152.020(G) and divisions (A) through (C) above;
(2) Have building setback 75 feet from downstream property lines;
(3) Driveways:
(a) Runoff must discharge onto pervious surface with a gravel strip or other spreading device;
(b) No more than 1,000 square feet of paved surface may discharge to any one point; and
(c) The length of flow on the pervious must exceed the length of the paved surface flow.
(4) The municipality can require more information or require mitigation of certain impacts through installation of stormwater management BMPs if there is a threat to property, health or safety.
(F) An applicant proposing regulated activities, after demonstrating compliance with divisions (A) through (C) above, may be exempted from various requirements of this chapter if documentation can be provided that a downstream human-made water body (i.e., reservoir, lake, human-made wetlands or other BMP) has been designed or modified to address the potential stormwater flooding and volume impacts of the proposed development.
(G) The purpose of this section is to ensure consistency of stormwater management planning between local ordinances and NPDES permitting (when required) and to ensure that the applicant has a single and clear set of stormwater management standards to which the applicant is subject. The city may accept alternative stormwater management controls under this section provided that:
(1) The city, in consultation with the PADEP (or delegated authority), determines that meeting the volume control requirements (see § 152.023) is not possible or places an undue hardship on the applicant.
(2) The alternative controls are documented to be acceptable to PADEP, or delegated authority, for NPDES requirements pertaining to post construction stormwater management requirements.
(3) The alternative controls are in compliance with all other sections of this chapter, including but not limited to, § 152.020(D) and divisions (A) through (C) above.
(H) Agricultural activity is 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.
(I) Forest management and timber operations are exempt from the rate and volume control requirement and SWM Site Plan preparation requirement of this chapter, provided the activities are performed according to the requirements of 25 Pa. Code Chapter 102. It should be noted that temporary roadways are not exempt.
(J) The city may deny or revoke any exemption pursuant to this section at any time for any project that the municipality believes may pose a threat to public health, safety, property or the environment.
(Ord. 1508, passed 12-20-2010)
(A) (1) All waiver requests must meet the provisions of divisions (G) below. Waivers shall not be issued from implementing such measures as necessary to:
(a) Meet state water quality standards and requirements; and
(b) Protect health, safety and property.
(B) If an applicant demonstrates to the satisfaction of the governing body of the city that any mandatory provision of this chapter is unreasonable or causes unique or undue hardship as it applies to a proposed project, and that an alternate design produces equal or better results within the context of meeting the purpose and requirements of this chapter, the governing body of the city, upon obtaining the comments and recommendations of the City Engineer, may grant a waiver or relief so that substantial justice may be done and the public interest is secured; provided, that such waiver will not have the effect of nullifying the intent and purpose of this chapter.
(C) Applicants shall submit requests for waivers in writing and these requests shall be included as part of a permit application submission. In the request for waiver, the applicant shall state in full the facts of undue hardship on which the request is based, identify the provision or provisions of the chapter that are causing such undue hardship and state the minimum waiver or relief that is necessary. The applicant shall state how the proposal in the applicant’s waiver request provides equal or better results in meeting the purpose and requirements of this chapter.
(D) The city shall keep a written record of all actions on waiver requests in the project file.
(E) The city may charge applicants fees for waiver requests sufficient to cover all costs incurred by the city to process the requests, including, but not limited to, administrative costs and costs for the City Engineer to review the waiver request.
(F) In granting waiver requests, the city may impose reasonable conditions that will, in its sole judgment, resolve the undue hardship while meeting the purpose and requirements of this chapter.
(G) The municipality may grant requests for waivers when the following findings are made by the city, when each is determined solely by the city to be applicable and relevant:
(1) The waiver shall result in an equal or better means of complying with the purpose and requirements of this chapter;
(2) The waiver is the minimum necessary to provide relief from undue hardship;
(3) The applicant is not requesting a waiver based solely on cost considerations;
(4) Existing down gradient stormwater problems will not be exacerbated by the proposed waiver request;
(5) Runoff is not being diverted to a different drainage area in a manner that may cause hardship to others;
(6) Increased flooding or ponding on off-site properties or roadways will not be caused by the waiver request;
(7) Potential icing conditions will not be caused by the waiver request;
(8) Increased or unusual municipal maintenance expenses will not result from the waiver request; and
(9) Operation and maintenance requirements are not reduced by the waiver request.
(Ord. 1508, passed 12-20-2010)
(A) The low impact development practices provided in the BMP Manual and in Appendix B of this chapter shall be utilized for all regulated activities to the maximum extent practicable.
(B) Stormwater runoff volume controls shall be implemented using the design storm method or the simplified method as defined 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 method; therefore, the applicant may select either method 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-I in the BMP Manual) is applicable to any sized regulated activity. This method requires detailed modeling based on site conditions.
(a) Do not increase the post-development total runoff volume for all storms equal to or less than the two-year 24-hour storm;
(b) For hydrologic modeling purposes:
1. Existing non-forested pervious areas must be considered meadow (good condition) for pre-development hydrologic calculations; and
2. Twenty percent of existing impervious area, when present within the proposed project site, shall be considered meadow (good condition) for pre-development hydrologic calculations for re-development.
(2) The simplified method (CG-2 in the BMP Manual) 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 surface waters of the state). 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 half-inch of the permanently removed runoff should be infiltrated; and
(d) Actual field infiltration tests at the location of the proposed elevation of the stormwater BMPs are required. Infiltration test shall be conducted in accordance with the BMP Manual. A minimum 48-hour notification of the municipality shall be provided to allow witnessing of the testing.
(3) In cases where it is not possible or desirable to use infiltration-based best management practices to partially fulfill the requirements in either divisions (B)(1) or (B)(2) above, the following procedure shall be provided to allow witnessing of the testing.
(a) At a minimum, the following documentation shall be provided to justify the decision to reduce the use of infiltration BMPs:
1. Description of and justification for field infiltration/permeability testing with respect to the type of test and test locations);
2. An interpretive narrative describing existing site soils and their structure as these relate to the interaction between soils and water. In addition to providing soil and soil profile descriptions, this narrative shall identify depth to seasonal high water tables and depth to bedrock, and provide a description of all subsurface elements (fragipans and other restrictive layers, geology and the like) that influence the direction and rate of subsurface water movement;
3. A qualitative assessment of the site’s contribution to annual aquifer recharge shall be made, along with identification of any restrictions or limitations associated with the use of engineered infiltration facilities; and
4. The provided documentation must be signed and sealed by a professional engineer or geologist.
(b) The following water quality pollutant load reductions will be required for all disturbed areas within the proposed development.
Pollutant Load | Units | Required reduction (%) |
Total nitrate (NO3) | Pounds | 50 |
Total phosphorous (TP) | Pounds | 85 |
Total suspended solids (TSS) | Pounds | 85 |
(c) The performance criteria for water quality best management practices shall be determined from the state’s Stormwater Best Management Practices Manual most current version.
(C) The applicable worksheets from the BMP Manual must be used in calculations to establish volume control.
(Ord. 1508, passed 12-20-2010)
(A) Lands contained within the county that have not had release rates established under an approved Stormwater Management Act, 32 P.S. §§ 680.1 et seq. Post-development discharge rates shall not exceed the pre-development discharge rates for the one-year, two-year, ten-year, 25-year, 50-year and 100-year storms.
(B) Lands contained within the county that have had release rates established under an approved Stormwater Management Act, 32 P.S. §§ 680.1 et seq. The post-development peak discharge rates shall be in accordance with the approved release rate map for the following watersheds (see appendices for release rate map): Lake Erie watersheds.
(Ord. 1508, passed 12-20-2010)
E&S STANDARDS
(A) The applicant shall meet requirements as contained in 25 Pa. Code, Chapters 92a and 102 as required and applicable as follows:
(1) The implementation and maintenance of erosion and sediment control BMPs;
(2) Development of written plans;
(3) Submission of plans for approval;
(4) Obtaining erosion and sediment control and NPDES permits; and
(5) Maintaining plans and permits on site.
(B) Evidence of any necessary plan or permit approval for earth disturbance activities from PADEP or the County Conservation District must be provided to Wayne Township.
(C) A copy of the approved Erosion and Sediment Control Plan and any other permit, as required by PADEP or the County Conservation District, shall be available at the project site at all times if required under Chapter 102.
(D) Construction of temporary roadways (e.g., for utility construction, timber harvesting and the like) shall comply with all applicable standards for erosion and sedimentation control and stream crossing regulations under 25 Pa. Code, Chapters 102 and 105. The Erosion and Sedimentation Control Plan shall be submitted to the County Conservation District for approval and shall address the following, as applicable:
(1) Design of the roadway system, including haul roads, skid roads, landing areas, trails and storage and staging areas;
(2) Runoff control structures (e.g., diversions, culverts, detention ponds and the like);
(3) Stream crossings for both perennial and intermittent streams;
(4) Access to public roadways, including design of rock construction entrance for mud and debris control; and
(5) A remediation plan for restoring the disturbed area through re-grading, topsoil placement, reseeding and other stabilization techniques, as required.
(E) Additional erosion and sedimentation control design standards and criteria that must be applied where infiltration BMPs are proposed include the following.
(1) Areas proposed for infiltration BMPs shall be protected from sedimentation and compaction during the construction phase, as to maintain their maximum infiltration capacity.
(2) Infiltration BMPs shall be protected from receiving sediment-laden runoff.
(3) The source of protection for infiltration BMPs shall be identified (i.e., orange construction fence surrounding the perimeter of the BMP).
(Ord. 1508, passed 12-20-2010)
DESIGN CRITERIA
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