Adding Pollutant Sources to Your Site Map

Various stormwater general permits require a site map as part of the Stormwater Management Plan. The site map typical must identify items such as structures, storm drains, stormwater direction of flow, and pollutants - among other items.

This training page addresses the Industrial Stormwater General Permit (ISWGP) special requirement related to the site map for identifying areas of pollutant contact on your site map (Special Requirement S3 B 1 g, on page 14 of the ISWGP).

Follow our video which details step-by-step guidance for identify areas of pollutant contact on your site. Learn how to add pollutant sources to your site map. Listed below are various resource materials referenced in the video.

Video Script

Want a handy printout of the video script to keep for your notes? Download the script.


Look through the Pollutant Sources photo gallery for examples of areas on your site that may include pollutant contact.

Reference Materials mentioned in video:

Industrial Stormwater General Permit

Stormwater Management Manual for Western WA

  • Minimum Technical Requirements and Site Planning - Volume I
  • Construction Stormwater Pollution Prevention - Volume II
  • Hydrologic Analysis and Flow Control Design/BMP's - Volume III
  • Source Control BMP's - Volume IV
  • Runoff Treatment BMP's - Volume V

Stormwater Management Manual for Eastern WA, PDF file

Example Site Assessment tables that list on-site activities and materials, PDF file

Sampling requirement tables excerpted from ISWGP, PDF file