(a) Under no circumstance shall the applicant be exempt from implementing such measures as necessary to:
(1) Meet special requirements for projects within high quality (HQ) and exceptional value (EV) watersheds (Section 1488.15(g)).
(b) The applicant must demonstrate that the following BMPs are being used 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.
(6) Direct runoff to pervious areas.
(c) The applicant must demonstrate that the proposed development/additional impervious area will not adversely impact the following:
(1) Capacities of existing drainage ways 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.
(6) Downstream property owners.
(d) An applicant proposing regulated activities, after demonstrating compliance with division (a) through (c) of this section , may be exempted from various requirements of this chapter according to the following table:
Table 302-1
0 SF new impervious area < 1,000 SF | Required: Exempt from additional requirements |
1,000 SF new impervious area < 2,500 SF | Required: Small Project SWM Application1 (See Appendices attached to Ordinance 2458) |
2,500 SF new impervious area < 5,000 SF | Required: Volume Control (Section 1488.12) and Small Project SWM Application (See Appendices attached to Ordinance 2458) |
5,000 SF new impervious area | |
1 The municipality can require the applicant to provide supplemental and additional information beyond the Small Project SWM Application if there is a threat to property, health or safety | |
All regulated activities must comply with the state water quality requirements.
(1) Complies with divisions (a) through (c) of this section; and
(2) Has building setbacks of at least 75 feet from downslope property lines; and
(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.
C. For each discharge point, the flow length on the pervious surface must exceed the flow length on the paved surface flow.
(f) The Municipality may accept alternative storm water management controls under this section provided that:
(1) The alternative controls are documented to be acceptable to PADEP (or delegated authority), for NPDES requirements pertaining to post-construction storm water management requirements.
(2) The alternative controls comply with all other sections of this chapter, including but not limited to Sections 1488.09(c) and 14880.10(a) through (c).
(g) Agricultural activities are exempt from the rate and SWM Site Plan preparation requirements of this chapter provided the activities are performed according to the requirements of 25 Pa. Code Chapter 102.
(h) Forest management and timber operations are exempt from the rate and volume 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. Refer to Section 1488.16 for additional information and guidance concerning timber operations.
(i) Exemptions from any provisions of this chapter shall not relieve the applicant from the requirements in Sections 1488.09(f) through (k).
(j) Proposed Municipal projects are bound to the following requirements and criteria:
Table 302-2
Type of Project | Description | Requirements | |
Roadway Restoration (Cont.) | Intersection* | Nominal channelization of intersections and addition of turning lanes. | Required: Minor practices and BMP implementation that uses low-impact practices such as: Preservation of existing vegetation Minimization of soil compaction Maintenance of erosion control and any PCSM BMPs |
Pavement | Replace portions, overlay, or mill and resurface the roadway's surface. | ||
Shoulders | Resurface, stabilize, upgrade (dirt or gravel to paved), or widen the existing shoulders within the existing footprint. | ||
Other | Replace and/or repair guide rail, signs, traffic signals, and drainage systems to their original specifications; various minor safety improvements. | ||
New Construction | Major Widening* | Addition of one or more travel lanes, including acceleration and deceleration lanes, to an existing road. | |
New Alignment* | New roadway corridor. | ||
Interchange* | Reconfiguration of ramps, lane modification within interchange area, etc. | ||
Municipal Facilities | New stockpile sites, buildings, or other structures or facilities not otherwise addressed by the requirements of this section | ||
* Projects falling into the noted categories and that have the potential to discharge into surface waters that have existing or designated HQ or EV uses (including EV wetlands), have impairments due to storm water, are connected to combined sewer systems, or have the potential to have an adverse effect on threatened or endangered species, or critical habitat for such species, are subject to additional storm water management requirements, beyond the requirements listed in the table. The additional BMP measures that must be considered and implemented for projects occurring in these areas are as follows:
Table 302-3
Constructed wetlands/Wet ponds | Significant detention of peak flow rates is needed and the contributing drainage area is large; retrofit existing detention basins are feasible. |
Permeable pavement | Parking lots only. |
Manufactured products: Subsurface storage, water quality inlets, etc. | Subsurface storage products are designed to attenuate peak runoff events through infiltration and/or discharge rate reduction. Storm sewer inlet structures or inserts are designed to minimize the discharge of solids, floatables, and oil/grease pollutants. Regular maintenance of these products is necessary.
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Projects occurring in the areas listed above and not previously bound to such requirements (roadway restoration projects), are also required to achieve the following targeted outcomes:
(1) For project areas within a release rate district, reduce the post-construction runoff peak rate as required by the release rate district in this chapter. For project areas not within a release rate district, reduce the post-construction runoff peak rate to the pre-construction peak rate for the one-year through 100-year storm events.
(2) Reduce the post-construction runoff volume to the pre-construction runoff volume for the two-year, 24-hour storm event and smaller.
(Ord. 2458. Passed 11-15-10.)