Stormwater

Navigating Your Permit

Do you need a permit?

Industrial Stormwater General Permits (ISGPs) are required for applicable industrial facilities that contribute pollutants to stormwater runoff that flows into surface water bodies. Use the flow chart in the permit assistance sheet to identify if your facility needs ISGP coverage. Ecology also issues permits for Construction, Municipalities, Sand and Gravel operations, and Boatyards. See Ecology’s website for more information on these permits.

Managing your permit

Understanding the Industrial Stormwater General Permit can be difficult for even the seasoned stormwater professional. The SCOI has prepared information to help navigate some of the more daunting requirements within the permit.

  • Stormwater Pollution Prevention Plan (SWPPP) – The SWPPP is a record of what is on your site and a guidebook of practices that you will use to prevent pollution from entering your stormwater system.
  • Recordkeeping and Documentation [PDF] – Knowing which records you need to keep and when you need to produce and update key documents is key in meeting your permit requirements.
  • Inspections – The ISGP requires that you do self-inspections of your property as well as comply with inspections conducted by Ecology. You may also be subject to inspection by other entities such as your local municipalities.
  • Best Management Practices – Best Management Practices (BMPs) are used to eliminate or reduce the potential to contaminate stormwater. Certain BMPs may be mandatory under your permit.
  • Stormwater Sampling [PDF] – Collecting accurate and representative samples is an essential component of complying with your permit.
  • Corrective Actions [PDF] – If you exceed your benchmark for any permit required parameter you will need to implement a corrective action. The type of corrective action you need to implement will depend on the number of exceedances you’ve had within the calendar year.

Identifying potential stormwater problems

It is cheaper to identify and investigate issues with your stormwater as soon as they arise. Ignoring or delaying maintenance and repairs can lead to third party lawsuits or a mandate from Ecology to install a treatment systems. The Washington Stormwater Center has a video outlining site investigation and source tracing efforts you can take if you are concerned about your stormwater discharge or if you want to identify potential issues before they become a problem.

Additional steps you can take to navigate potential problems include:

  • Examine the stormwater on or leaving your site. Is there a sheen? Is it turbid or cloudy? These visual observation can indicate a spill or pollutant source that should be investigated.
  • Closely review the reports from the laboratory. It can be important to note and troubleshoot an increase in pollutant concentrations, even if they are below the benchmark values, to avoid the need for a corrective action.
  • Inspect your catch basins, any treatment BMPs, and other components of your stormwater drainage system. Drainage problems on your site or within stormwater system can indicate a clog or source of sediment in the system.
  • Check Ecology’s PARIS database against your Discharge Monitoring Reports. Ensure that the data has been uploaded completely and accurately.