Township of Washington, PA Article XX Environmental Performance Standards

[Added 4-24-1997 by Ord. No. 1997-1]

§ 131-111 Purpose.

A. These regulations are intended to protect the rights of the residents of Washington Township to enjoy clean air, pure water and the natural scenic, historic and aesthetic values of the environment as set forth in the Pennsylvania Constitution and in other commonwealth and federal statutes. In particular, it is the Township's purpose, through the environmental performance standards established by this article, to adjust the allowable density of development and to establish minimum required building areas free of environmental constraints in order to conserve the following natural features:

(1) Natural features identified as land or water resources areas, e.g., groundwater recharge zones, springs, streams, agriculturally suited soils, prime wildlife habitats and areas constituting high recreational and other amenity value.

(2) Natural features performing beneficial ambient air quality or microdimate functions, e.g., by abating glare and noise, entrapping dust and other particulate and contributing to the reduction of climatic stress and energy costs.

(3) Natural features which, if disturbed, may cause hazards or stress to life and property, e.g., steep slopes and floodplains.

B. Under the authority of the Pennsylvania Municipalities Planning Code (Act of 247 of 1968, as amended) and the Second Class Township Code and in recognition of the fact that its natural features contribute to the welfare of its residents, the Township has enacted these regulations to provide reasonable standards governing the conservation of such features.

C. No provisions of these regulations shall be construed to deny the right of any property owner to use his land as may be permitted by the Township's Zoning Ordinance. Rather, it is the purpose of these regulations to ensure that such uses minimize disturbances to natural features and that reasonable measures are taken to mitigate any adverse impacts of such uses.

§ 131-112 Applicability.

[Amended 8-14-1997 by Ord. No. 1997-7; 3-25-2004 by Ord. No. 2004-1]

The provisions of this article apply to any and all lots created by subdivision or land development in the A, WSC, R1, R2, HDV, C, LI and GI Zoning Districts.

§ 131-113 Area, bulk and layout.

A. Conformance with purposes. Site planning, including the layout of lots, streets and structures, shall be in compliance with the purposes of this article and with the overall purposes of this chapter.

B. Adjusted tract area (ATA), density, buildable area and exemptions. The maximum density in all zoning districts shall be determined by applying the following density adjustment factors to the tract of land under application for subdivision and/or land development. The adjusted tract area, that area remaining after the application of density factors, shall be used to calculate the maximum number of units permitted on a tract.

(1) In determining the ATA, the following factors shall be deducted, in their entirety, from the gross tract acreage:

(a) All areas within existing public or private streets or within existing rights-of-way, including overhead rights-of-way of utility lines.

(b) All areas of floodway as defined in § 131-47A of this chapter.

(c) Open space required by § 107-28 of the Washington Township Subdivision Code shall not be deducted, except that open space area within the floodway and rights-of-way of utility lines.

(2) In determining the ATA, the following environmental weighting factors (EWF's) shall be applied to and subtracted from the gross tract acreage:

(a) Slopes. Multiply acreage of land with natural ground slopes in excess of 25% by an EWF of 0.75. Multiply acreage of land with natural ground slopes of between 15% and 25% by an EWF of 0.50. Slope shall be based on five-foot contour intervals or less, and only those areas of contiguous slopes in excess of 15% exceeding 2,000 square feet shall be counted.

(b) Floodplain. Multiply acreage of land in the one-hundred-year floodplain (excluding floodways or wetlands within floodplains) by an EWF of 0.50.

(c) Wetlands. Multiply acreage of land comprised of wetlands by an EWF of 0.95.

(d) Seasonal high-water table. Multiply acreage of land with a seasonal high-water table less than three feet from the surface for three or more months of the year by an EWF of 0.67. (Proposed developments where water supply and sewage disposal are provided by either a community system or a public system shall apply an EWF of 0.33.) In the absence of a high-intensity soil survey conducted by a licensed soil scientist, data from the medium-intensity soil survey published by the USDA Soil Conservation Service shall be used. The Board of Supervisors may require a high-intensity soil survey to be conducted if, in its judgment, the medium-intensity survey is inaccurate or inadequate.

(e) Shallow bedrock. Multiply acreage of soils where the depth to bedrock is less than 3.5 feet by an EWF of 0.67. Multiply acreage of soils with surface ledge or rock outcroppings, comprising an area of 500 square feet or greater, by an EWF of 0.95. (Proposed developments where both water supply and sewage disposal are provided by either a community system or a public system shall apply an EWF of 0.33 for shallow bedrock and 0.90 for rock outcroppings, respectively.) In the absence of a high-intensity soil survey conducted by a licensed soil scientist, data from the medium-intensity soil survey published by the USDA Soil Conservation Service shall be used. The Board of Supervisors may require a high-intensity soil survey to be conducted if, in its reasonable judgment, the medium-intensity survey is inaccurate or inadequate.

(3) Minimum required buildable area.

(a) The minimum required buildable area in any zoning district shall be not less than 50 feet wide and 50 feet deep and in no case less than 2,500 square feet, contiguous and not interrupted by rights-of-way, utility easements or by the Floodplain Overlay District.

(b) In determining the minimum required buildable area, the following shall be excluded, and their acreages shall be listed on the preliminary and final plans.

[1] Any area within public or private street rights-of-way or overhead utility easement.

[2] Any area comprising a stormwater management basin.

[3] Any area of Floodplain Overlay District.

[4] Any area of slope in excess of 25%.

[5] Setback areas required by area and bulk regulations of the applicable zoning district.

[6] Any area of sanitary sewage fields.

[7] Any area of wetlands.

(4) Application of environmental weighting factors. In determining the adjusted tract area, if a portion of the gross tract area contains more than one of the EWF constraints, then only the most restrictive of the EWF's shall apply to that portion of the tract.