Township of Worcester, PA Stormwater Management Application and Permit Requirements

A feasibility analysis that evaluates the potential application of infiltration, flow attenuation, bioretention, wetland, or wet pond BMPs must be submitted with the stormwater management site plans required in Article IV.

The feasibility analysis must allow the Township to review the general soil characteristics of a site and the proposed development for that site and determine if infiltration BMPs or wet pond or artificial wetland BMPs could have been more thoroughly pursued for use by the applicant. The information required in the analysis shall be detailed enough to determine the potential applicability of these BMPs for a proposed development, but general enough not to force an applicant into incurring excessive cost associated with conducting laborious field and/or laboratory soil testing for a site which ultimately may not be suitable for infiltration or wet pond or artificial wetland BMP implementation. Applicants are expected to use these BMPs wherever possible and are required to provide adequate justification if these BMPs are not to be implemented. Applicants for those sites that are determined to be generally suitable from these analyses (taking into consideration the areal extent of suitable soils necessary to accommodate an infiltration or wet pond or wetland BMP for the type and size of development proposed) are required to conduct the detailed soil testing and other feasibility testing required in other sections of this chapter which contain the description and additional design criteria of these BMPs.

This analysis shall provide:

(a)

A general assessment of the anticipated additional runoff based on the design storm and postdevelopment condition and utilizing the calculation procedures required in § 129-19;

(b)

An indication of drainage areas on the development site resulting in impervious, pervious, and rooftop runoff;

(c)

An indication of type of land use (residential, nonresidential) generating the impervious surface runoff;

(d)

A delineation of soils on the site from the NRCS, Soil Survey of Montgomery County and on-site soil study. The soil study shall be conducted by a soil scientist and shall include sufficient probes/deep holes to evaluate application of BMPs;

(e)

An indication of soils generally suitable for infiltration and/or wet pond/artificial wetland BMPs;

(f)

The calculated acreage of suitable soils for infiltration BMPs and wet pond or artificial wetland BMPs and percentage of suitable soils based on total site acreage;

(g)

The calculated acreage of suitable soils for infiltration BMPs and wet pond or artificial wetland BMPs made unavailable due to proposed development layout and justification that an alternative development layout which would reduce impact on suitable soil availability is unfeasible;

(h)

An analysis of potential infiltration or wet pond or artificial wetland BMPs which could be implemented to manage the projected postdevelopment runoff with consideration of suitable soil availability runoff point and type of land use [Subsection C(3)(b) and (c) above] and the general design standards and maintenance issues included in this chapter, including an indication of how most postdevelopment runoff can be managed by these BMPs (e.g., the entire postdevelopment runoff or partial amount of runoff expressed as a percentage); and

(i)

The rationale for a decision to not proceed with implementation of infiltration BMPs or wet pond or artificial wetland BMPs such as excessive cost of implementation, insufficient soil suitability, and development constraints.

A detailed geologic evaluation of the project site pursuant to § 129-15E and Appendix B[1] of this chapter shall be performed to determine the suitability of recharge facilities. The evaluation shall be performed by a qualified geologist and/or soil scientist and shall address, at a minimum, soil permeability, depth to bedrock, susceptibility to sinkhole formation, and subgrade stability.

Editor's Note: Appendix B is included as an attachment to this chapter.

Whenever a stormwater management facility will be located in an area underlain by limestone, a geological evaluation of the proposed location shall be conducted to determine susceptibility to sinkhole formations. The design of all facilities over limestone formations shall include measures to prevent groundwater contamination and, where necessary, sinkhole formation. Soils used for the construction of basins shall have low-erodibility factors ("K" factors). Installation of an impermeable liner shall be required in detention basins to be constructed over or in close proximity (less than 150 feet) to limestone. It shall be the applicant's responsibility to verify whether the site is underlain by limestone. The following note shall be attached to all stormwater management site plans and signed and sealed by the applicant's professional engineer: "I, __________, certify that the proposed stormwater management facility (circle one) is/is not underlain by limestone."

General:

General description of project.

General description of permanent stormwater management techniques, including construction specifications of the materials to be used for stormwater management facilities.

Complete hydrologic, hydraulic, and structural computations for all stormwater management facilities.

Four copies of the stormwater management site plan for the parcel shall be submitted on twenty-four-inch-by-thirty-six-inch sheets and shall be prepared in a form that meets the requirements for recording at the offices of the Recorder of Deeds of Montgomery County. The contents of the plan shall include, but not be limited to:

The location of the project relative to highways, municipalities, or other identifiable landmarks.

Watershed(s) within which the project is located (e.g., Skippack Creek, Wissahickon Creek, Stony Creek/Saw Mill Run).

Existing contours at intervals of two feet. In areas of steep slopes (greater than 25%), five-foot contours may be used.

Existing streams, lakes, ponds, or other bodies of water within the project area and all drainage channels leading to such bodies of water.

(5)

Other physical features including riparian corridors, flood hazard boundaries, sinkholes, streams, existing drainagecourses, swales, wetlands, areas of natural vegetation to be preserved, and the total extent of the upstream area draining through the site.

(6)

The locations of all existing and proposed utilities, sanitary sewers, and waterlines located on the site and/or within 50 feet of property lines with minimum setback distances for all existing and proposed water supply wells and on-lot sewage disposal systems.

(7)

An overlay showing soil names and boundaries. This overlay shall include a table on the map showing the recharge capabilities of each soil represented on site in inches per hour and describe their recharge or infiltration capabilities.

(8)

Proposed changes to the land surface and vegetative cover, including a tabulation of impervious surface area which identifies the type of surface and the quantity of existing impervious surface area, existing impervious surface area to be removed and proposed impervious surface area.

(9)

Proposed structures, roads, paved areas, and buildings. Where pervious pavement is proposed for parking lots, recreational facilities, nondedicated streets, or other areas, detailed pervious pavement construction specifications shall be noted on the plan.

(10)

Final contours at intervals at two feet.

(11)

The name of the development, the name and address of the owner of the property, and the name of the individual or firm preparing the plan.

(12)

The date of submission.

(13)

A graphic and written scale of one inch equals no more than 50 feet. For tracts of 20 acres or more, the scale may be one inch equals no more than 100 feet.

(14)

A North arrow.

(15)

The total tract boundary and size with distances marked to the nearest foot and bearings to the nearest degree.

(16)

Existing and proposed land use(s).

(17)

A key map showing all existing man-made features beyond the property boundary that may be affected by the project.

(18)

Horizontal and vertical profiles of all open channels, including hydraulic capacity.

(19)

All existing and proposed stormwater management facility and/or drainage easements described by metes and bounds, including the purpose and ownership and maintenance provisions for each easement.

(20)

A twenty-foot-wide access easement around all stormwater management facilities that would provide ingress to and egress from a public right-of-way or paved driveway within an existing or proposed easement that accesses a public right-of-way.

(21)

A note on the plan indicating the location and responsibility for maintenance of stormwater management facilities that would be located off site. All off-site facilities shall meet the performance standards and design criteria specified in this chapter.

(22)

A construction detail of any improvements made to sinkholes and the location of all notes to be posted, as specified in this chapter.

(23)

A statement, signed by the landowner, acknowledging the stormwater management system to be a permanent fixture that can be altered or removed only after approval of a revised plan by the Township, which shall be recorded with the record plan and which shall be applicable to all future landowners.

(24)

The location of all erosion and sedimentation control facilities.

(25)

The following signature block for the design engineer:

(Design engineer), on this date (date of signature), has reviewed and hereby certify that the Stormwater Management Site Plan meets all design standards and criteria of the Worcester Township Stormwater Management Ordinance No. 278.

(26)

The stormwater management site plan shall include an operation and maintenance plan for all existing and proposed stormwater management/BMP facilities, addressing long-term ownership and maintenance responsibilities for such facilities, including schedule for operation and maintenance activities.

Required supplemental information:

A written description of the following information shall be submitted:

(a)

The overall stormwater management concept for the project.

(b)

Stormwater runoff computations as specified in this chapter.

(c)

Stormwater management techniques to be applied both during and after development.

(d)

Expected project time schedule.

A soil erosion and sedimentation control plan, where applicable, including all reviews and approvals, as required by PADEP and/or Montgomery County Conservation District.

A geologic assessment of the effects of runoff on sinkholes as specified in this chapter.

The effect of the project (in terms of runoff volume, peak flow, and discharge duration) on adjacent properties and on any existing Township stormwater collection system that may receive runoff from the project site.

(5)

A declaration of adequacy and highway occupancy permit from the PADOT District Office when utilization of a PADOT storm drainage system is proposed.

(6)

An operations and maintenance (O&M) plan for all existing and proposed physical stormwater facilities, as well as schedules and costs for O&M activities. The plan shall address long-term ownership and responsibilities for O&M.

Stormwater management BMPs.

All stormwater management facilities must be located on a plan and described in detail.

When groundwater recharge methods such as seepage pits, beds, or trenches are proposed, the locations of existing and proposed septic tank infiltration areas and drinking water wells must be shown. A minimum separation distance of no less than 50 feet shall be provided between any septic system and any facility used for stormwater management. An analysis shall be submitted to verify that stormwater infiltration shall not affect groundwater elevations of the septic drain field site if this distance is approved by the Township to be less than 50 feet. In no case shall this distance be less than 20 feet.

All calculations, assumptions, and criteria used in the design of the stormwater management facilities must be shown. If multiple facilities are proposed in conjunction with each other, such as infiltration best management practices with vegetation-based management practices, a summary narrative shall be included describing any sequence and how the facilities are meant to function with each other to manage stormwater runoff.

All stormwater management/BMP facility easements required by this chapter must be shown on the stormwater management site plan, including the bearing and distance of each segment of the easement(s) boundary.

§ 129-23 Simplified stormwater management site plan (SSMSP) contents and requirements.

For all regulated activities that qualify for exemption of certain provisions of this chapter pursuant to § 129-5C, and that are required to install a predesigned infiltration facility(s) in accordance with Worcester Township design and construction criteria (to be provided by the Township at the time of permit application), a simplified stormwater management site plan (SSMSP) is required and shall include the following items:

Four copies of the completed Township Stormwater Management Application form.

Stormwater management review fee and escrow, as established by separate resolution of the Township Supervisors.

Four copies of the simplified stormwater management site plan for the parcel containing, at a minimum, the following information:

Property boundaries and area of the site, based on deed information, or field survey.

Location map identifying the site relative to streets and other parcels in the vicinity of the site.

Location of significant natural and existing man-made features, including wetlands, watercourses, riparian corridors, woodlands, steep slopes, structures, parking areas, driveways, utilities, flood hazard boundaries, sinkholes, wells, and septic systems within 200 feet of proposed impervious surface, regardless of the location of the property boundary.

Location and dimensions of existing and proposed impervious surface and other improvements, with setbacks drawn to relate the location of same to property lines, streets, and existing features. Impervious surface area tabulation must be provided identifying existing area of impervious surface, existing impervious surface area to be removed, and proposed impervious surface area.

(5)

North arrow.

(6)

Plan scale, as applicable.

(7)

Existing contours at intervals of two feet. In areas of steep slopes (greater than 25%), five-foot contours may be used.

(8)

Proposed contours at intervals at two feet as well as spot elevations as necessary to provide sufficient clarification of positive slope and drainage divides.

(9)

Infiltration/BMP facility design calculations and construction details.

(10)

An overlay on the site showing soil names and boundaries from the NRCS, Soil Survey of Montgomery and Philadelphia Counties or on-site soil study, conducted by a soil scientist. This overlay shall include a table on the map showing the recharge capabilities of each soil represented onsite in inches per hour and describe their recharge or infiltration capabilities.

(11)

Watershed(s) within which the project is located (e.g., Skippack Creek, Wissahickon Creek, Stony Creek/Saw Mill Run).

(12)

A graphic and written scale of one inch equals no more than 50 feet. For tracts of 20 acres or more, the scale may be one inch equals no more than 100 feet.

(13)

The name of the development, the name and address of the owner of the property, and the name of the individual or firm preparing the plan.

(14)

A soil erosion and sedimentation control plan, where applicable, including all reviews and approvals, as required by PADEP and/or Montgomery Conservation District.

(15)

A certification on the plan, signed by the landowner, acknowledging the stormwater management system to be a permanent fixture that cannot be altered or removed without written approval of a revised plan by the Township, which shall be recorded with the record plan and which shall be applicable to all future landowners.

(16)

Other information deemed necessary by the Township Engineer to determine compliance with exemption criteria contained in § 129-5B.

(17)

The following signature block for the design engineer:

(Design engineer), on this date (date of signature), has reviewed and hereby certify that the stormwater management plan meets all design standards and criteria of the Worcester Township Stormwater Management Ordinance No. 278.

(18)

Locations of existing and proposed septic tank infiltration areas and all wells must be shown. A minimum separation distance of no less than 50 feet shall be provided between any septic system and any facility used for stormwater management. An analysis shall be required to verify that stormwater infiltration shall not affect groundwater elevations of the septic drain field site, if this distance is approved by the Township to be less than 50 feet. In no case shall this distance be less than 20 feet.

(19)

It shall be the applicant's responsibility to verify whether the site is underlain by limestone. The following note shall be attached to all simplified stormwater management site plans and signed and sealed by the applicant's professional engineer:

"I, __________, certify that the proposed stormwater management facility (circle one) is/is not underlain by limestone."

§ 129-24 Plan submission.

For all activities regulated by this chapter, the steps below shall be followed for submission of a SMSP or SSMSP (both referred to in this section as "plan"). For any activities that require a PADEP permit regulated under Chapter 105 (Dam Safety and Waterway Management) or Chapter 106 (Floodplain Management) of PADEP's Rules and Regulations,[1] a PADOT highway occupancy permit, or any other permit under applicable local, state, or federal regulations, the permit(s) shall be supplied as part of the plan.

The SMSP shall be submitted by the applicant as part of any preliminary subdivision and/or land development plan submission.

A minimum of four copies of the plan shall be submitted in conjunction with regulated activities not exempt pursuant to § 129-5B of this chapter. Additional copies shall be submitted if requested by the Township.

Distribution of the plan will be as follows:

Two copies to the Township accompanied by the requisite Township review fee and escrow, as specified in this chapter.

Two copies to the Township Engineer.

Editor's Note: See 25 Pa. Code Chapters 105 and 106.

§ 129-25 Review of stormwater management site plan and simplified stormwater management site plan.

The Township Engineer shall review the plan for consistency with the adopted Watershed Act 167 Stormwater Management Plan and applicable Township ordinances. The Township shall require receipt of a complete plan, as specified in this chapter.

The Township Engineer shall review the plan for any subdivision or land development against the Subdivision and Land Development Ordinance[1] provisions not superseded by this chapter.

§ 129-27 Resubmission of disapproved stormwater management site plans and simplified stormwater management site plans.

Editor's Note: See Ch. 130, Subdivision and Land Development.

For activities regulated by this chapter (not including subdivision or land development), the Township Engineer shall review the plan for conformance with the Watershed Act 167 Stormwater Management Plan. The Township Engineer will forward a review letter to the Township with a copy to the applicant. Any disapproved plan may be revised by the applicant and resubmitted consistent with this chapter.

The Township shall not approve any subdivision or land development or regulated activities specified in § 129-4E(1) and (2) of this chapter if the plan has been found to be inconsistent with the Watershed Act 167 Stormwater Management Plan. All required permits from PADEP must be obtained prior to, or as a requirement of, final approval.

The Worcester Township Building Code Official shall not issue a building permit for any regulated activity specified in § 129-4 of this chapter if the stormwater management site plan has been found to be inconsistent with the adopted Watershed Act 167 Stormwater Management Plan, as determined by the Township Engineer, or without considering the comments of the Township Engineer. All required permits from PADEP must be obtained prior to issuance of a building permit.

The Township's approval of a stormwater management site plan or simplified stormwater management site plan prepared in conjunction with a stormwater management permit application (for a regulated activity that is not a subdivision or land development, and which is not exempt from provisions of this chapter pursuant to § 129-5B) shall be valid for a period not to exceed one year. This time period shall commence on the date that the Township signs and issues a stormwater management permit. If stormwater management facilities included in the approved plan have not been constructed, or if an as-built survey of these facilities pursuant to § 129-28 of this chapter has not been approved within this time period, the Township may consider the plan disapproved and may revoke any and all permits. Plans that are considered disapproved by the Township shall be resubmitted in accordance with § 129-27 of this chapter.

The Township's approval of a stormwater management site plan prepared in conjunction with an approved subdivision or land development shall remain valid and protected from any change in Township codes and ordinances for a period no greater than five years from the date of preliminary subdivision and/or land development plan approval, pursuant to the provisions of the Pennsylvania Municipalities Planning Code.[2]

[2]

Editor's Note: See 53 P.S. § 10101 et seq.

§ 129-26 Modification of plans.

A modification to a submitted stormwater management site plan or simplified stormwater management site plan for a development site that involves a change in stormwater management facilities or techniques, or that involves the relocation or redesign of stormwater management facilities, or that is necessary because soil or other conditions are not as stated on the plan as determined by the Township Engineer, shall require a resubmission of a modified plan consistent with § 129-27 of this chapter and be subject to review as specified in § 129-25 of this chapter.

A modification to an already approved or disapproved plan shall be submitted to the Township, accompanied by the applicable Township review fee and escrow. A modification to a plan for which a formal action has not been taken by the Township shall be submitted to the Township, accompanied by the applicable Township review fee and escrow.

A disapproved stormwater management site plan or simplified stormwater management site plan may be resubmitted, with revisions addressing the Township Engineer's concerns, documented in writing, to the Township Engineer in accordance with § 129-24 of this chapter and be subject to review as specified in § 129-25 of this chapter. The applicable Township review fee must accompany resubmission of a disapproved plan.

§ 129-28 As-built plans.

The applicant for any regulated activity requiring a stormwater management site plan and stormwater management permit shall be responsible for completing an as-built survey, sealed by a professional engineer licensed in the Commonwealth of Pennsylvania or a registered surveyor licensed in the Commonwealth of Pennsylvania, of all stormwater management facilities/improvements included in the approved plan. An as-built survey is not required for infiltration BMPs installed in conjunction with a simplified stormwater management site plan. The as-built survey and an explanation of any discrepancies with the design plans shall be submitted to the Township Engineer for approval. In no case shall the Township approve the as-built survey until the Township receives a copy of an approved declaration of adequacy, highway occupancy permit from the PADOT District Office (if applicable), any applicable permits from PADEP, and NPDES notice of termination (if applicable) approved by PADEP or the Montgomery County Conservation District.

Completed stormwater management facilities and BMPs, including detention/retention basins, shall be surveyed by a professional land surveyor or engineer licensed in the Commonwealth of Pennsylvania, to verify compliance with the character of stormwater management facilities as depicted on the approved plan. As-constructed plans shall be submitted to Worcester Township for review and approval, upon completion of construction of all facilities and prior to offer of dedication of any public facilities and/or submission of financial security for the required maintenance period associated with subdivisions and land developments. Public facilities will not be accepted by Worcester Township until such time the as-constructed plans have been reviewed and approved by the Township Engineer.

§ 129-29 Retention of plans at project site.

A set of plans approved by the Township shall be on file at the site throughout the duration of the development activity. Periodic inspections may be made by the Township or designee during development activities.

§ 129-30 Adherence to approved plan.

It shall be unlawful for any person to undertake any regulated activity on any property except as provided for in the approved plan and pursuant to the requirements of this chapter. It shall be unlawful to alter or remove any stormwater management facility or BMP required by the plan pursuant to this chapter or to allow the property to remain in a condition which does not conform to the approved plan.

§ 129-31 Certification of completion.

At the completion of the project, and as a prerequisite for the release of the performance guarantee required pursuant to § 129-37, the owner or his representatives shall:

Provide a set of as-built drawings pursuant to § 129-28 of this chapter and/or Subdivision and Land Development Ordinance[1] requirements. The as-built submission shall include a certification of completion signed by a licensed, qualified professional verifying that all permanent stormwater management/BMP facilities have been constructed according to the approved stormwater management site plan and specifications.