3. The project plan shall specify permanent stormwater BMPs to be implemented, operated
   and maintained to meet legal water quality, rate and volume requirements. Ifmethods other
   than low impact development (LID) and green infrastructure methods are proposed to
   achieve the volume and rate controls required under this ordinance, the SWM Site Plan
   must include a detailed justification demonstrating that the use of LID and green
   infrastructure is not practicable.
4. In order to protect and maintain water quality, additional stormwater runoff created by the
   development project must be captured, stored and treated. In addition, post construction
   stormwater infiltration of runoff must replicate preconstruction infiltration of runoff to the
   maximum extent possible with the exception of hot spots. As a minimum, this shall be a
   volume of additional runoff generated by a 2-year, 24 hour storm. Preferred BMP's for a
   hot spot include storm inlet filters, proprietary stormwater quality devices, underground
   detention tanks, detention ponds with forebays, tree planting, green roof. Permeable
   pavement, infiltration BMP's, and rain gardens are not recommended for hotspots.
5. In addition to the provisions set forth in paragraphs A. through c., inclusive, as set forth
   above, all regulated development activities within the [Municipality] shall be designed,
   implemented, operated and maintained to meet the purposes of this Ordinance, through
   these two elements:

1. Erosion and sediment control during the earth disturbance activities (e.g., during
   construction).
2. Water quality, rate and volume protection measures after completion of earth
   disturbance activities (e.g., post-construction stormwater management), including
   operations and maintenance.

6. No regulated development activities within Bolivar Borough shall commence until the
   requirements of this Ordinance are met.
7. All best management practices (BMPs) used to meet the requirements of this Ordinance
   shall conform to the State water quality requirements, and any more stringent requirements
   as determined by Bolivar Borough.
8. LID and green infrastructure techniques described in the P A DEP Stormwater BMP Manual
   2006 or most current edition are encouraged.

§30B. Watershed Standards

1. The stormwater management performance standards in this Ordinance are intended to
   implement the provisions, standards and criteria contained in the Pennsylvania Stormwater
   Management Act (Act 167), 32 P.S. §680.1 et seq. If there is any discrepancy between the
   provisions of this Ordinance and the provisions, standards and criteria of the Act, or if a
   storm water management plan is subsequently approved and adopted by the appropriate
   governmental agency or body, then the provisions, standards and criteria of the current
   watershed plan shall govern.
2. Management of stormwater runoff is key objective of25 Pa.Code, Chapter 93, of the DEP Regulations, because runoff can change the physical, chemical and biological integrity of waterbodies thereby impacting rate, volume and water quality.

3. The project plan shall describe how these rate, volume and water quality protection
   requirements will be met. Infiltration BMPs shall be evaluated and utilized to the maximum
   extent possible to manage the net change in stormwater runoff generated so that post
   construction discharges do not degrade the physical, chemical or biological characteristics
   of the receiving waters. These BMPs may be used to satisfy all or part of the requirements
   found within this Ordinance.
4. Refer to the Stormwater Performance Districts outlined in Appendix A, and the
   Westmoreland County Integrated Water Resources Plan (IWRP) at
   www.westmorelandstormwater.org. The project plan shall describe how the proposed
   project will address performance standards, impairments, and pollutant loading found in the
   IWRP. For areas not covered by a stormwater performance district, the release rate shall be
   80% of the pre-development peak flow as set by the municipality.

      §309.         Design Criteria for Stormwater Management Facilities and BMPs.

A. General Criteria.

1. Applicants may select runoff control techniques, or a combination of techniques,
   which are most suitable to control stormwater runoff from the development site.
   Refer to the Acceptable Computation Methodologies table of this ordinance. All
   controls must be subject to approval of the Bolivar Borough engineer and the WCD.
   The [Municipality] engineer may request specific information on design and/or
   operating features of the proposed stormwater controls in order to determine their
   suitability and adequacy in terms of the standards of this Ordinance.
2. If the proposed development site is located in an impaired water shed according to
   Category 4 of the P A Integrated Water Quality Monitoring and Assessm ent Report,
   or in a watershed with a TMDL according to Category 5 of the same Report, the
   applicant shall identify the source and cause of impairment and shall propose, if
   required or applicable the use ofBMPs to mitigate any impacts to the waters.
3. The applicant should consider the effect of the proposed stormwater management
   techniques on any special soil conditions or geological hazards which may exist on
   the development site. In the event such conditions are identified on the site, the
   Bolivar Borough engineer may require in depth studies by a competent geotechnical
   engineer. Not all stormwater control methods may be advisable or allowable at a
   particular development site.
4. The applicant shall consider the effect of the proposed stormwater management
   techniques on existing stream impairments and pollutant loading. Refer to the
   Westmoreland County Integrated Water Resources Plan (IWRP) at
   www.westmorelandstormwater.org .
5. The applicant shall consider existing conditions on the site for the prior [five] years
   to determine prevailing land use and impervious cover, and shall consider 20% of
   existing impervious cover as meadow for pre-existing conditions on redevelopment
   sites.
6. The stormwater management practices to be used in developing a stormwater management plan for a particular site shall be selected according to the following order of preference:

                           a.       Site planning for locating proposed buildings, impervious areas and grading which minimizes disruption of the natural site characteristics especially utilizing low impact development techniques.

2. Minimization of impervious areas and promotion of retentive grading.
3. Implementation of non-structural measures (refer to the PA DEP
   Stormwater BMP Manual 2006 or current edition).

                           d.      Implementation of innovative / green infrastructure structural measures (refer to the PA DEP Stormwater BMP Manual 2006 or current edition).

                           e.       Stormwater detention/retention structures.

7. Any BMP which is a dam, culvert, stream obstruction or encroachment or outfall
   as defined in 25 Pa.Code, Chapter 105, shall be designed according to the
   requirements in those regulations.
8. Drainage easements shall be provided for all stormwater conveyance and BMPs
   serving multiple properties and not located within a public right of way. Easements
   shall include ingress and egress to a public right of way, and shall be recorded at
   the County with the final plan. Terms of easement shall prohibit excavation or
   placement of fill or structures and any alteration that may adversely affect the flow
   of stormwater within any portion of the easement.
9. No person shall install, create, modify, remove, fill, landscape or otherwise alter
   or place any structure, soil, rock, material or vegetation in or on, or otherwise
   adversely affect, any stormwater management facility or any area within a
   stormwater easement without the written approval of the Bolivar Borough.
10. Persons engaged in land development activities shall provide the required [financial
    security, O&M Agreements] to the [municipality] as outlined in the Appendix B.

B. Criteria for Stormwater Management Facilities and BMPs.

1. If stormwater management facilities and BMPs are utilized for the development
   site, the facility(s) shall be designed such that post-development peak runoff rates
   from the developed site are controlled to those rates defined by a Stormwater
   Management Performance District for the 100 year storm frequencies. Rainfall
   data shall be obtained from NOAA Atlas 14 or other source as approved by the
   municipality.
2. All stormwater management facilities and BMPs shall be equipped with
   outlet/overflow structures to provide rate discharge control for the designated storm
   frequencies. Provision shall also be made to safely pass the entire post-development
   100-year storm without breaching or otherwise damaging the facilities, downstream
   or neighboring properties.
3. Release of stormwater flow from a development site must be to an existing
   stormwater conveyance or easement whether natural or man-made. Calculations
   and information shall be presented as to the ownership, responsible party, capacity,
   and stability of such conveyance. Release of 'sheet flow' as from a level spreader,
   will be permitted on a case-by-case basis as approved by the municipality and
   WCD.
4. All stormwater management facilities and BMPs shall be designed to control volume and water quality as defined by the Stormwater Management Performance District. Refer to Appendix A.

1. Shared stormwater management facilities and BMPs, which provide control of
   runoff for more than one development site within a single subarea may be
   considered and are encouraged. Such facilities shall meet the criteria contained in
   this Section. In addition, runoff from the development sites involved shall be
   conveyed to the facility in a manner that avoids adverse impacts (such as flooding
   or erosion) to channels and properties located between the development site and the
   shared storage facilities.
2. Where stormwater management facilities and BMPs will be utilized, multiple use
   facilities, such as wetlands, lakes, ballfields or similar recreational/open space uses
   are encouraged wherever feasible, subject to the approval of the [Municipality].
3. Other considerations which shall be incorporated into the design of the stormwater
   management facilities and BMPs include:
4. Inflow and outflow structures shall be designed and installed to prevent
   erosion and embankments, cuts, fills and bottoms of impoundment type
   structures should be protected from soil erosion.
5. Control and removal of debris both in the storage structure and in inlet or
   outlet devices shall be a design consideration.
6. Inflow and outflow structures, pumping stations and other structures shall
   be designed and protected, using safety benches, trash racks, energy
   dissipaters and other means to minimize safety hazards.
7. Access may be restricted as specified by [the provisions for fencing
   swimming pools] as found in the municipality Zoning Ordinance, and in
   appropriate instances such restriction of access may include fencing in a
   minimum height of 6 feet
8. Interior slopes of storage ponds shall not exceed a ratio of three to one
   horizontal to vertical dimension with a combination of interior and exterior
   slopes not exceeding five. Steeper slopes may be approved by the
   municipality engineer if documented to be stable by a geotechnical analysis.

                           f       Landscaping shall be provided for the facility which stabilizes disturbed
areas and preserves the natural and beneficial values of the surrounding
area.

7. Facility shall be located to facilitate maintenance, considering the frequency
   and type of equipment that will be required.
8. Underground detention / retention / infiltration facilities shall be equipped
   with open grate inlet or manhole access to facilitate visual inspections.

C. Criteria for Collection/Conveyance Facilities.

1. All stormwater runoff collection or conveyance facilities, whether storm sewers or
   other open or closed channels, shall be designed 'in accordance with the following
   basic standards:

1. All building sites shall use measures to provide drainage away from and
   around the structure in order to prevent any potential flooding damage as
   much as practical. Such measures shall include grading the surrounding
   lawn or pavement area so that it slopes away from the structure by a minimum of 5% slope over a minimum distance of 10 feet; raising the floor of the structure so that it is a minimum of 6 inches above the predominate surrounding land elevation and above the designated floodplain elevation for those located within a floodplain; eliminating or waterproofing penetrations thru the structure's walls or foundation; constructing berms, curbs, or swales to divert surface water around the structure; arranging roof and area drains to carry water away from the structure.