Washington Department of Ecology (Ecology) issued the draft Industrial Stormwater General Permit (ISGP) on May 15, 2024. The current ISGP was issued in November 2019 and is scheduled to expire on December 31, 2024. There are notable changes proposed for the next ISGP which will likely affect most industrial facilities. The public comment period started on May 14, 2024, and will now end on July 15, 2024 at 11:59 pm. Ecology will hold two online workshops and hearings in June. For more details regarding the draft ISGP, fact sheet explaining the basis for proposed changes, links to register for online workshops and ways to submit comments, please refer to Ecology’s website here.

In the draft ISGP, Ecology proposed the following changes:

• Clarifications and updates to stormwater systems and activities covered by the ISGP;
• Updates to required best management practices (BMPs) and Stormwater Pollution Prevention Plans (SWPPP);
• Additional sampling requirements for sources releasing 6PPD-quinone and per- and polyfluoroalkyl substances (PFAS);
• Clarification and additional requirements for reporting.

Updates to the ISGP Coverage

Ecology clarified that discharges directly to groundwater should be covered by the ISGP. In the previous version of ISGP, sampling is not required for groundwater discharges unless specifically requested by Ecology. Starting in 2025, Ecology will require sites with groundwater discharges to sample if the site is required to sample for PFAS, or when the discharges are deemed to be a “functional equivalent to a point source discharge to surface waters” based on the County of Maui vs Hawaii Wildlife Fund 2020 Supreme Court case. Additionally, all groundwater discharges should implement treatment/infiltration BMPs consistent with the 2024 Stormwater Management Manual (SWMM). Discharges to groundwater through an Underground Injection Control (UIC) well should comply with UIC regulations and requirements.

For the facilities under the transportation category (NAICS codes 482xxx-485xxx), Ecology requires permit coverage for facilities with material handling and storage operations. For those facilities with existing permit coverage, material handling and storage operations will need be included for BMP implementation and assessment of representative sampling locations. Ecology determined that “these areas are significant contributors of pollutants due to the increased tire wear and material exposed to stormwater which cause solids, zinc, and other pollution to leave the facility”.

In this draft ISGP, Ecology removed the automatic approval for facilities applying for Conditional No Exposure (CNE) exemptions. Ecology expects to only grant CNE approval “after inspection to confirm that there is no possible exposure to pollutants”.

Updates to BMPs and SWPPP

All BMPs should be designed, installed, and maintained in accordance with the 2024 SWMM. A summary of changes for the 2024 SWMM compared to the 2019 SWMM is presented in a previous Trinity eNews article. In the draft ISGP, dumpsters should be under cover or with a storm-resistant lid, and the cover should prevent litter from blowing out of the dumpster and prevent stormwater generating or releasing leachate. Ecology added a definition of “dumpster” which appears to be applicable to most waste receptacles, bins, and containers used at facilities.

Ecology will require the following changes to the SWPPP:

• The site map should identify all stormwater conveyance directions, including underground stormwater conveyance to UIC locations.
• Areas where industrial activities are conducted, especially areas where equipment cleaning is conducted, need to be identified on the site map. The definition of “industrial activity” will be updated to capture most common activities located at industrial facilities, including industrial plant yards and material handling locations.
• A maintenance log needs to be kept along with the SWPPP to document the completed maintenance tasks.
• As part of the Spill Prevention and Emergency Cleanup Plan, stormwater conveyance systems cannot be used as part of the secondary containment calculation. Verification of no contamination is required prior to releasing the accumulated water in containment areas, similar to the requirements in 40 CFR 112 for Spill Prevention Controls and Countermeasures (SPCC) Plans. The storm drains receiving runoff from areas where maintenance occurs should be blocked during fueling and vehicle fluid changes. Lastly, any liquid chemical release onsite regardless of size or flowability is considered a spill and should be logged and addressed.
• Employee training should include all employees regardless of full, part, or seasonal time, and new hires should be trained within 30 days of hire. Additionally, contractors and vendors who have duties should be trained unless a trained employee is supervising the activity at all times. Training records need to be kept with the SWPPP.

For existing sites that need to update their existing SWPPP to comply with the new ISGP, the BMPs and updated SWPPP shall be implemented by March 1, 2025.

Updates to Sampling

Ecology intended to give more flexibility on where sampling can occur, considering the safety and logistical issues of sampling wharves and piers at marine cargo handling facilities. A sampling point waiver request may be authorized case by case via a Modification of Coverage.

6PPD-quinone is added to the benchmark monitoring parameter for transportation activities, petroleum bulk stations and terminals, and warehousing and storage facilities. The sampling requirement for transportation facilities will become effective on January 1, 2028. PFAS monitoring is added for air transportation facilities and waste management and remediation services facilities. Both 6PPD-quinone and PFAS sampling results are “report only”, meaning a benchmark level has not been established yet.

Updates to Reporting Requirements

For corrective actions, Ecology clarified that any waiver or time extension request will be issued in writing instead of providing a response within 60 days of receipt of a complete request. Any benchmark exceedance prior to Level 2 or Level 3 corrective action implementation due date does not count towards additional corrective actions. For Level 3 corrective actions, the deadline for the engineering report will be 6 months after the last day of the calendar year in which the Level 3 corrective action was triggered.

Ecology requires that the annual report include findings identified by all review or visual means, instead of the findings only from monthly inspections. The review or visual means include but not limited to SWPPP reviews, audits by consultants or providers of technical assistance, inspection reports or other notification made by authorities, visual observations, and/or the monthly inspections.

Ecology also clarifies that immediate reporting is required for any noncompliance that may endanger health or the environment, and any violation of a maximum daily discharge limit. Exceedance of any numeric effluent limitation will not require immediate reporting to Ecology; however, immediate actions to minimize potential pollution should still apply.

Lastly, all reports, including the Annual Gross Revenue Form due on May 15th, should be submitted electronically through Ecology’s Water Quality Permitting Portal, unless an eReporting waiver is granted by Ecology.

Notice of Intent

A Notice of Intent (NOI) for existing facilities is required to be submitted by July 5, 2024 to maintain coverage under the ISGP. As part of the NOI submittal, facilities are required to submit an updated site map including any updated structural control measures and potentially updates to address the requirements of the draft ISGP.

Next Steps

We can assist you with understanding these new requirements, including assistance with updating your SWPPP, site map, and/or NOI to comply the upcoming ISGP. If you would like submit a public comment by July 15, or have any questions regarding the upcoming ISGP, please contact Hui Cheng or call 253.262.5888.