PA DEP Updates Industrial Stormwater General Permit

From the desk of James P. Cinelli, P.E., BCEE

Updated 10/6/16

On September 24, 2016, the Pennsylvania Department of Environmental Protection (DEP) reissued the NPDES General Permit for Discharges of Stormwater Associated with Industrial Activity (PAG-03). This general permit replaces the previous version that was issued by DEP on December 5, 2010, and adds significant new requirements for permit holders. These are summarized below.


  • It is now the permittee’s responsibility to comply with any new requirements that DEP adds to the General Permit when it is reissued.
  • An annual fee of $500 is now required. It is called the Annual NOI Installment Fee and is to be submitted with the annual report by May 1 of each year.
  • The NOI filing fee has been reduced from $750 to $500.


Two additional eligibility criteria have been added, which will require certain facilities to obtain an NPDES individual permit for their stormwater discharges. These include:

  • If a wasteload allocation (WLA) has been assigned to a stormwater discharge in a Total Maximum Daily Load (TMDL), the discharge may not be covered by the General Permit; and
  • If a facility withdraws 2 million gallons of water per day or more, where 25% or more is used for cooling purposes, the facility’s stormwater discharges may not be covered by the General Permit.

Stormwater Best Management Practices (BMPs)

General BMPs applicable to all facilities have changed substantially. Permittees that had coverage under the previous version of the PAG-03 have until September 24, 2017 to implement any new BMPs. Permittees are now required to do the following:

  • Install spill/overflow protection equipment on storage tanks.
  • For unlidded dumpsters and roll-offs, control discharges with such measures as secondary containment or treatment.
  • Place velocity dissipation devices at stormwater discharge locations.
  • Keep spill kits on-site, and in areas where spills may occur.

Semiannual Inspections

The prior permit required annual site inspections. Under the new general permit, permittees must now perform these inspections semiannually, and one of these inspections must be performed when a stormwater discharge is occurring. The time of the inspection was not stipulated in the prior permit.

Stormwater Monitoring and Benchmark Values

The most significant changes to the General Permit involve stormwater sampling, including the establishment of “benchmark values” for a number of pollutants. While DEP states that the benchmark values are not effluent limitations and exceedances do not constitute permit violations, if an outfall discharge exceeds the values during two consecutive monitoring periods, a Corrective Action Plan must be submitted to DEP within 90 days of the end of the monitoring period. The major changes to stormwater monitoring are as follows:

  • Upon written notice from DEP, permittees may be required to install structures or devices that are considered necessary to conduct stormwater sampling.
  • The prior permit required that stormwater samples be collected within the first hour of discharge, if it was impracticable to perform sample collection in the first 30 minutes. The new permit still indicates a preference to perform sampling in the first 30 minutes of discharge, but does not contain the reference to the first hour of sampling.
  • Appendix J facilities, which is a catch-all category for facilities whose SIC codes do not subject them to the requirements of another Appendix, are no longer able to perform inspections in lieu of stormwater monitoring. Thus, all permitted facilities are now required to conduct stormwater sampling. Note that facilities that are newly subject to sampling requirements will need to start sampling during the first semiannual period of 2017.
  • All facilities are now required to perform sampling semiannually. Some facilities (e.g., small airports, power plants) previously performed sampling on an annual basis.
  • For most facilities that have performed sampling in the past, the number of parameters to be analyzed has been reduced.

Electronic Reporting

All dischargers covered by the General Permit will now be required to submit their discharge monitoring reports using DEP’s eDMR system. DMRs are due 28 days after each semiannual period (January 28 and July 28). Existing permittees have until December 21, 2016 to register for the eDMR system.

No Exposure Certification (NEC)

  • A $500 fee is now required with the NEC submittal.
  • NECs must be updated every five years.
  • Both new and existing facilities must conduct one round of stormwater sampling to confirm that the stormwater discharge is “non-polluting”.
  • A Stormwater PPC Plan must be submitted with the NEC.