2025 ISGP Reissuance
Ecology recently released the final version of the 2025 Industrial Stormwater General Permit. This permit is set to go into effect on January 1, 2025 and expires on December 31, 2029. The article below contains key documents, important dates, and a quick review of the changes in the 2025 permit. This list is not comprehensive and permittees and other interested parties should read the permit in full to fully understand their permit requirements.
Key Documents:
Read the Full Permit here Read the Response to Comments
Read the Fact Sheet Read the Focus On sheet
Ecology ISGP Homepage WSC ISGP Assistance
Key Changes from the 2020 Permit
*Please note- These changes discuss only the changes from the current permit (2020) to the 2025 reissuance. Deviations from the draft permit are not discussed to avoid confusion.
New Sampling Parameters (for certain NAICS):
Starting in 2025, PFAS will need to be sampled from waste management facilities (NAICS:562xxx). Air transportation facilities (NAICS:481xxx) with known, current, or historical use of Aqueous Film Forming Foam (AFFF) will also need to sample for PFAS starting in 2025.
6PPD-quinone will need to be sampled by transportation, hazardous waste, and waste management facilities beginning in 2028. Click here to read it in the permit.
Updated Definition of Industrial Activity:
The new Industrial Activity definition now includes material handling activities at intermodal facilities or facilities where cargo and materials are moved between ships, trains, and trucks. This definition also clarifies that it excludes areas located on plant lands separate from the plant’s industrial activities, such as office buildings and accompanying parking lots as long as the drainage from the excluded area is not mixed with stormwater from the industrial area. Click here to read it in the permit.
Vendor/Contractor Training Requirements:
Facilities will be required to provide SWPPP training to all contractors/vendors who perform duties that have the potential to impact stormwater quality in areas of industrial activities subject to this permit. They may be excluded if the permittee has an employee who has been trained on the SWPPP supervising the activity at all times. Click here to read it in the permit.
Discharges to Ground:
There is a lot of new language regarding discharges to ground. One change is that facilities that must sample for PFAS should also sample their discharges to ground. There is also a provision that if ecology deems a discharge point to groundwater a functional equivalent to a point source discharge to surface water, permittees would have to sample that discharge. There is also clarification that facilities discharging to the ground must have all treatment. infiltration BMPs designed, installed, and maintained in accordance with the appropriate SWMM or functionally equivalent as found S3.A.2. Click here to read it in the permit.
Conditional No Exposure:
Under the 2025 permit, Ecology will respond to all CNE requests in writing within 90 days. CNE requests will only be granted only after Ecology informs the applicant in writing. This eliminates automatic approval after 90 days which was found in the 2020 permit. Click here to read it in the permit.
Site Map Updates:
Permittees should update their site maps to now include areas where equipment cleaning is conducted, locations where vehicles are parked and stored, areas where industrial activity is conducted, and locations of groundwater discharge points. These updates are in addition to the previous site map requirements. Click here to read it in the permit.
Tire Storage:
All new and used tires should now be stored under cover or in a storm-resistant shelter. Click here to read it in the permit.
BMP Maintenance Log:
Permittees now will need to keep a BMP maintenance log. This log must be made available upon request by Ecology or the local Jurisdiction. Click here to read it in the permit.
Spill Prevention and Emergency Cleanup Plan:
Minor changes include clarification that stormwater conveyance systems cannot be used as part of the secondary containment calculation for storage of chemicals. Also, clarification that containment areas with a valve must keep valve closed until verification that there is no visible oil sheen present. There are also some other minor adjustments around spill prevention regarding to maintenance activity and leaking vehicles. Click here to read it in the permit.
SWPPP Training Timeline:
All employees, contractors/ vendors requiring training should be trained within 90 days of hire, that timeline shifts to within 30 days of hire if they are part-time or seasonal. These trainings need to be logged and the log should be kept with the SWPPP and made available upon request. Click here to read it in the permit.
Wash Water Discharge to Ground:
The new permit clarifies that this process wastewater must not be allowed to discharge to the ground, along with the previous prohibitions of not comingle with stormwater or entering storm drains. Click here to read it in the permit.
Sample Locations:
The new permit clarifies some unique circumstances when it comes to sample points including onsite receiving bodies, shared regional ponds, sampling discharges to ground (PFAS only), what to do with corrective actions when a benchmark is exceeded at a substantially identical discharge point, and clarifying exceptions to sampling do not apply to a point subject to effluent limits. Click here to read it in the permit.
Sample Point Waiver:
The process to get a sampling point waiver is introduced in this permit. This is for cases when a sample location is not feasible to sample from. Click here to read it in the permit.
Additional Laboratory Documentation:
Permittees will now be required to include a chain of custody and case narrative with their previously required laboratory documentation. Case narrative was also defined as “the narrative provided in a laboratory report describing the condition of the samples upon laboratory receipt; how they were stored at the laboratory; any issues with analyses; and related quality assurance/quality control issues that may affect data integrity/useability, as applicable.” Click here to read it in the permit. Click here to read case narrative definition.
Consistent Attainment Sampling Timeline:
Permittees who have achieved consistent attainment may take their annual (first flush) sample any time of the year. Previously this sample was required to be taken during the 4th quarter. *Clarification: These permittees must sample the first fall storm, however, that first fall storm may occur after q4. Click here to read it in the permit.
pH sampling:
pH samples must now be measured with a calibrated meter, paper is no longer allowed. Click here to read it in the permit.
Illicit Connections:
If a permittee were to find a historical, illicit connection they weren’t aware of, the permittee must inform ecology of their findings and how they plan to remove the illicit connection to maintain compliance under the ISGP. Click here to read it in the permit.
Puget Sound Sediment Cleanup Sites:
There were some minor changes to the description of Puget Sound sediment cleanup site, as well as how storm drain solids samples are taken for Puget Sound sediment cleanup sites. Click here to read it in the permit.
Site Inspection Frequency:
The new permit states that permittees should have at least one week between their monthly inspections. (i.e. you couldn’t inspect on the 31st of October and the 1st of November). Click here to read it in the permit.
Dumpster Inspections:
Permittees will need to inspect dumpsters annually for holes or defects to identify and control leakage. Click here to read it in the permit.
Corrective Action Tally:
The new permit has added language clarifying that benchmark exceedances are tallied facility-wide. This means that corresponding corrective action levels are implemented based on your facility-wide tally of benchmark exceedances. Click here to read it in the permit.
Engineering Report Extension:
The engineering report for applicable treatment BMPs is effectively moved from May 15th to June 30th the year following a level 3 trigger. Click here to read it in the permit.
Records Retention:
This permit has clarified that either hard copies or electronic records are acceptable for records retention requirements. Click here to read it in the permit.
Reporting Permit Violations:
This permit has added criteria that require reporting to ecology within 24 hours including: noncompliance that may endanger human health or the environment, or any violation of a maximum daily discharge limit in this permit. Click here to read it in the permit.
Definitions:
This permit has defined or modified the definitions of several important terms that are relevant to compliance. Click here to read it in the permit.
