Pennsylvania Stormwater Update

03 June, 2024

Navigating the PADEP’s New NPDES General Permit Requirements

The current NPDES PAG-02 General Permit issued by the Pennsylvania Department of Environmental Protection (PADEP) will expire on December 7, 2024.

Existing permits will need to be either renewed or terminated before that date to remain in compliance. PADEP plans to have a new permit in place by December 8, 2024.


Note: This permit expiration only applies to General NPDES Permits. Individual NPDES Permits are issued under a different authorization and will not be affected by this expiration.  If you are not sure which type of permit you have, connect with your land development consultant.


Here’s what development teams need to know to remain compliant and strategize erosion control and post construction stormwater management designs moving forward.

What Are My Options for Existing NPDES General Permits

There are two options available to keep an existing permit in compliance. If construction of a project is complete and the disturbed areas are stabilized, the permit can be closed out through a Notice of Termination (NOT). If the NOT is approved before December 7th, no further action is required.

If an NOT cannot be approved by December 7th, the existing NPDES General Permit will need to be renewed. PADEP has indicated that the renewal process will be administrative in nature, and that new, more streamlined renewal documents will be available this fall.  A $500 application fee is also anticipated for the renewal.

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Please note, the implications of not terminating or renewing a permit may be significant. The developers on active projects with expired NPDES permits may be requested to voluntarily cease all earth disturbance activities and/or may be subject to a PADEP compliance order requiring all earth disturbance activities to cease and desist until a new permit has been obtained. New general NPDES permits issued on or after December 8, 2024 may include new permit conditions, similar to what is outlined below.

What’s Changing for New NPDES General Permits

PADEP is proposing several changes to the NPDES General Permit requirements. A draft of the updated permit is available on PADEP’s website. A summary of the proposed changes has been published in the PA Bulletin. The public comment period for the Draft has been closed, and the PADEP is currently processing the feedback.

A new General Permit is planned to go into effect on December 8, 2024. Below is a summary of some of the changes that may have the biggest impact on development projects.

  • EPA Technology-Based Standards: New standards for discharge effluent limits, along with two new requirements for construction dewatering. Stormwater discharged from the site would need to be treated by a series of at least two Stormwater Control Measures (SCMs). Depending on the final requirements, owners and developers could see an increase in design and construction cost for additional stormwater management structures.
  • Site Inspections: Can only be conducted by qualified personnel as demonstrated by specified training or certification. While there may be a grace period to allow for persons to become certified to perform site inspection, this rule could impact the project’s timeline and cost to find available, certified personnel.
  • Co-Permittees: Eliminating the requirement to submit Co-Permittee Acknowledgement and Co-Permittee Liability Release Forms, which will impact contractors. The DEP or county conservation district will request the names of operators during inspections. Operators may be held liable for violations.
  • Instrument Recording: Public recording of construction documents, including proof of the recording, will be required to be submitted PRIOR to the scheduling of a pre-construction meeting. This requirement has the potential to delay construction start. Development teams are strongly encouraged to work closely with their attorneys and consultants early on to get this process underway, in an effort to avoid delays.
  • Imported Fill and Groundwater Contamination: Clarification on the requirements of “clean fill.” All fill material to be imported onto a site needs to be clean fill in accordance with PADEP’s Management of Fill Policy unless it is a site enrolled in Act 2 or approved to use regulated fill. A requirement to notify PADEP of newly discovered groundwater contamination is also proposed.
  • Erosion Potential Analysis: More commonly referred to as “offsite discharge analysis,” this requirement would aim to standardize the requirements for analyzing stormwater flow paths when not directly connected to a waterway. Since some conservation districts across the state are already requiring such an analysis, Bohler’s team is ready for a more streamlined process to incorporate across the board.
  • Annual Report: An annual report detailing the status of the project will need to be submitted to PADEP, County Conservation District (CCD) and the Municipality. The report will need to provide information on the stage of construction, deviations from the approved permit requirements, summary of site inspections and an anticipated date for NOT submittal. The report is to also include a summary of PCSM feature construction.
  • SCM Construction Certification Form: A standardized form to document the construction completion of each permanent stormwater structure. This form will require close collaboration with the contractor during construction, as a licensed professional will need to observe construction of the structure before it gets covered up by backfill or other construction activity, and then complete, sign, and submit the form within 30 days.
  • Construction Confirmation Testing for Infiltration Capacity: Post-construction testing is proposed for infiltration-based SCMs to ensure as-built ponding time or drawdown times are within the tolerated range. This requirement will require close coordination with the contractor during construction and will likely add cost for additional infiltration testing.
  • New Property Owner Notification Form: Requires permittees who sell the property while the permit is open to notify the new owner of all PCSM SCMs and their long-term Operation and Maintenance requirements. A copy of the form must be provided to PADEP/CCD within 30 days of the property transfer.
  • Impervious Surfaces for Residential Subdivisions: The post-construction impervious surface area used in the stormwater management design will need to account for possible future improvements, such as decks, patios, and pools. While this requirement will prevent the need for the owner to redesign and resubmit for additional impervious area, it could impact the project’s cost in providing larger stormwater management measures. The draft indicates that PADEP would expect the impervious area used to be either the ordinance permitted maximum or a factor of at least 10% additional area.

Moving Forward

Bohler’s design and consulting teams across Pennsylvania are available to provide guidance and to handle submission requirements related to obtaining a NOT or renewal for your existing NPDES General Permit.

Contact your local office

This is a fluid situation. We are actively monitoring the renewal process in an effort to empower Bohler’s clients to make well-informed, proactive decisions and stay ahead of potential nonconformities on their sites.

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