On March 20, 2024, the Washington Department of Ecology issued a draft Water Treatment Plant General Permit for public comment. Water treatment plants that engage in filter backwash activities and pollutant discharge must obtain coverage under this permit to comply with state and federal water-quality laws. The current permit, issued on July 17, 2019, expires on Aug. 31, 2024. The draft permit and accompanying fact sheet, which explains the technical basis for the permit, are available for review and public comment from March 20, 2024, through May 3, 2024, at 11:59 p.m.

A few key changes in the new draft permit are:

1. Ecology added a new provision regarding per- and polyfluoroalkyl substances (PFAS) into the permit. The definition of significant change in section G-4.6, Reporting a Cause for Modification or Revocation, and in section S-6.2.4, Notification of a Change in Covered Activities, now includes changes to a facility made to address PFAS in source, finished, or waste waters.
2. Ecology has added conditions to section S-1 that give it the right to determine permit coverage for facilities with production rates less than 5,000 gallons per day, if they are deemed significant contributors to pollutants or potential violators of water-quality standards.
3. A new section, S-1.2.1, authorizes Water Treatment Plants (WTP) covered under the permit to discharge filter backwash water and stormwater to state waters under specified limits and conditions.
4. Mandatory inclusions in section S-3.1, Operations and Maintenance Manual, now require procedures for proper operation and maintenance of facilities, including sampling procedures, quality assurance, and laboratory controls to appear in the O&M Manual.
5. A new section, S-5.2.5 titled Consistent Attainment, allows permittees to request a reduction in sampling frequency based on consistent attainment of permit limits until September 30, 2029.
6. Additional requirements for turbidity sampling in section S-5.4 mandate daily sampling if turbidity exceeds 250 NTUs until specific conditions are met.
7. Section G-2.3 provides expanded details regarding enforcement actions for violations of permit conditions.
8. A new section, G-4.10, Notice of Termination Request, outlines conditions for approval of a Notice of Termination (NOT) request when discharges no longer require coverage under the permit.

Stakeholders are encouraged to participate in the public comment period to provide valuable feedback about the draft permit. Facilities that have already applied for coverage by March 4, 2024, and are covered under the existing permit, will be covered under the new permit. The draft permit and accompanying fact sheet that explains the technical basis for the permit, are both available for review and public comment from March 20, 2024 through May 3, 2024, 11:59 p.m., and informational workshops and public hearings have been scheduled.