On November 20, 2019, the Washington State Department of Ecology (Ecology) issued the final Industrial Stormwater General Permit (ISGP) covering years 2020 through 2024. Ecology issued the final permit following a period of public comment on the draft permit published in May 2019. Existing permit holders were required to apply for permit renewal by July 3, 2019.

Key changes from the previous permit (covering 2015 - 2019) implemented in the final updated ISGP include:

  1. Two additional covered industrial groups
  2. Changes to the stormwater pollution prevention plan (SWPPP) requirements
  3. Change of the date of first fall storm event period
  4. Lower benchmark values for lead and silver

The following summarizes major changes implemented in the 2020 issue of the ISGP:

  • Industrial activities based on NAICS codes as opposed to SIC codes
  • Updates to industrial activity descriptions
  • Addition of two covered industrial activity groups:
    • Construction, Transportation, Mining, and Forestry Machinery and Equipment Rental and Leasing (NAICS 53241x)
    • Marine Construction (ECY003)
  • All applications and reports to be submitted online via Secure Access Washington (SAW)
    • Electronic reporting requirement may be waived upon submission of a completed Electronic Reporting Waiver form
  • Added language relating to exemption for facilities that discharge only to groundwater
  • Updated requirements for stormwater pollution prevention plans (SWPPPs), including:
    • Addition of requirement for SWPPP to be developed by qualified personnel
    • Update to list of referenced stormwater management manuals
  • Date of first fall storm event period changed from October 1 to September 1
  • Update to sampling requirements for facilities under consistent attainment
    • Now required to sample once annually following consistent compliance over eight consecutive quarterly samples
  • Decrease in benchmark values for lead and silver
  • Updates to laboratory quantification values for numerous parameters
  • Addition of benchmark values for TSS and petroleum hydrocarbons for the following industrial activity groups:
    • Transportation Equipment Manufacturing
    • Construction, Transportation, Mining, and Forestry Machinery and Equipment Rental and Leasing
    • Coal Mining
    • Oil and Gas Extraction
    • Nonmetallic Mining and Quarrying, except Fuels
    • Petroleum and Coal Products Manufacturing
    • Nonmetallic Mineral Product Manufacturing
    • Steam Electric Power Generation
    • Marine Industrial Construction
  • Addition of benchmark values for new Marine Industrial Construction industrial activity group
  • Addition of sampling parameters for E. coli and Enterococci for discharges to impaired waters
  • Explanations required for reports of no discharge or no sample in quarterly discharge monitoring reports
  • Option to store SWPPP at an online URL accessible to the public

Facilities are required to comply with all standards of the new ISGP, including required updates to facility SWPPPs and new or updated benchmark and effluent limitations, by the effective date of January 1, 2020. All new quarterly sampling and reporting requirements are applicable beginning Q1 2020.

For questions regarding stormwater compliance tasks including SWPPP updates, notices of intent, corrective action planning, and training, please contact Ben Leers at (253) 867-5600