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New Multi-Sector General Permit For Stormwater – What Does It Mean For Your State’s General Permit For Industrial Stormwater?

Posted: April 6th, 2021

Authors: All4 Staff 

U.S. EPA recently issued its Multi-Sector General Permit (MSGP) for stormwater discharges associated with industrial activity with an effective date of March 1, 2021.  Facilities with coverage under the 2015 MSGP have until May 30, 2021 to submit a new Notice of Intent (NOI).  This new MSGP initially affects those industrial facilities in Massachusetts, New Hampshire, Puerto Rico, and New Mexico whose Standard Industrial Classifications (SIC) are covered by the permit, because U.S. EPA directly manages the NPDES programs in those jurisdictions.  Those affected facilities need to submit their new NOI to the agency and evaluate the new permit for conditions that affect their work practices and the content of their Stormwater Pollution Prevention Plan.  However, for the rest of the country, the MSGP provides clues to your state’s future industrial stormwater permit(s).

Every five years, U.S. EPA issues a new MSGP that incorporates the “best of” new monitoring, management practices, and trends selected from state programs.  The MSGP becomes the “road map” for the states’ industrial stormwater permit changes over the next five years, when the states re-issue those permits.  Because the state industrial stormwater permits program started in the 1990’s, state industrial stormwater permits have diverged from the MSGP and do not have the same look and feel of the MSGP.  The authorizing laws at the state level allow the state agencies to be creative when it comes to alignment with the new MSGP.  Here are some examples:

  • Some states have a single MSGP (e.g., Pennsylvania, South Carolina, and Georgia), while others have sector-specific general industrial stormwater permits (e.g., New Jersey, Alabama, and North Carolina).
  • The names of the permits and the associated plans vary widely – for example, Alabama uses “Best Management Practices” plan instead of Stormwater Pollution Prevention Plan
  • The tiering of benchmark results is a process where benchmark exceedances drive additional monitoring and implementation of more controls to reduce stormwater pollutant concentration. Many states have incorporated benchmarking – but tiering of benchmark results has been limited to a few states (e.g., North Carolina and Oregon).
  • The renewal cycle for the state industrial stormwater permits can be offset from the Federal MSGP by up to five years. Additional delays can occur when industry groups file lawsuits against a proposed permit.  In an interesting twist, Tennessee renewed its previous permit, based on the 2015 federal MSGP, for 2 additional years in 2020.  That 2-year offset will allow TDEC to review and potentially incorporate these 2021 federal MSGP changes.

A number of states will renew their industrial stormwater permits over the next several months – such as South Carolina, Texas, and Pennsylvania – and will consider incorporating these new features of the MSGP:

  • Permit Streamlining by re-sequencing the permit sections (Monitoring, Corrective Actions and “Additional Implementation Measures” (AIM), and then Pollution Prevention Planning requirements) and using active voice permit language: S. EPA believes that sequencing the permit in this order will follow how readers process the requirements.  They also worded the eligibility requirements in affirmative terms versus “assumed ineligibility unless a condition was met.” (e.g., “Samples must be collected…” now reads “You must collect samples…”).  Some states will re-sequence their permit language and will use active voice (sometimes referred to as “plain language”) in their general industrial stormwater permit.  Other states that elect to stay away from benchmark tiering may adopt the “voice” without addressing the “sequence” in their permits.
  • Monitoring changes, including indicator monitoring (report only) for pH, Total Suspended Solids (TSS) and Chemical Oxygen Demand (COD) for certain subsectors that do not have benchmark monitoring requirements; indicator monitoring for polycyclic aromatic hydrocarbons (PAHs) for certain subsectors and operators; updated benchmark monitoring (values and schedule); and impaired waters monitoring:
    • Under the previous MSGP, benchmark monitoring did not apply to 45% of regulated facilities as noted by U.S. EPA in the informational webinar for this MSGP. To gather data, U.S. EPA is requiring facilities from sectors that did not have benchmark requirements to conduct “report-only” indicator monitoring for pH, TSS, and COD on a quarterly basis throughout the permit term.
    • Facilities in certain subsectors that might use or store PAHs must conduct “report-only” indicator monitoring for PAHs.
    • Under the previous MSGP, benchmark monitoring could be discontinued after four quarters with monitoring results below the benchmark threshold. This permit requires monitoring in the first and fourth year of the permit term.
    • Under the previous MSGP, facilities discharging to impaired waters monitored once/year for pollutants causing impairments to the waters and then discontinued monitoring if the pollutant is not detected or not expected in the discharge. This permit requires facilities discharging to impaired waters without a total maximum daily load (TMDL)to monitor for all pollutants causing impairment.
    • These monitoring changes are likely to receive push-back from many state agencies and from the industry groups in those states, due to their increased cost and precedent-setting nature.
  • Additional corrective action measures called AIM for benchmark monitoring exceedances in three tiers: Benchmark tiering in the 2021 MSGP forces the facility to evaluate/implement control measures and conduct on-going monitoring at baseline and higher tiers.  In the 2021 MSGP model, the facility starts with reviewing the Pollution Prevention Plan and its control measures at the first tier, implementing additional measures at the second tier, and permanent structural source and treatment controls at the third tier.  This change may be the most interesting to watch over the 5-year renewal for state industrial stormwater permit, as those states that modify the MSGP approach could actually make benchmark tiering more complicated.
  • Adding a new requirement for signage and making the SWPPP publicly available as an attachment to the NOI electronically filed or on a public website: This signage requirement is parallel to the discharge signage requirement for sites with individual permits.  In an era where the state stormwater enforcement teams are relying more and more on the public to alert them to non-compliance, this new tool for signage – and continuing to make the Pollution Prevention Plan information more publicly available – will likely be incorporated widely.
  • Addition of a new Part, which requires consideration of enhanced stormwater control measures for facilities that could be impacted by major storm events, such as hurricanes, storm surge and flood events. Examples of such enhanced stormwater control measures include elevating materials, temporarily reducing outdoor storage prior to storm events, and delaying deliveries in advance of storm events.  Some states may find this “consideration” useful, but it would be difficult to enforce implementation.

ALL4 has summarized key changes in the 2021 MSGP here, with an eye toward how states might incorporate the new MSGP features in their five-year state industrial stormwater permit renewals.  If you need help with tracking developments in stormwater permitting or development of your facility’s Pollution Prevention Plan, please reach out to Paul Hagerty at 610.422.1168 or phagerty@all4inc.com.


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