Instructions for using Google Earth to find your hydrologic unit code.

An Investment Grade Efficiency Audit is a requirement of state infrastructure funding

Design requirements for infiltration trenches with soils considered a treatment BMP

2017 comments by interagency team about Bioassessment Alternatives to support refinements to Water Quality Policy 1-11, the Water Quality Assessment and Total Maximum Daily Load Programs

This FAQ outlines questions and answers that Industrial Stormwater General Permit holders may find helpful. This document is intended as guidance only, and does not modify or otherwise change the permit requirements in the Industrial Stormwater General Permit.

Use this form for your monthly inspections if you are industrial stormwater permit holder. Inspections must be conducted by a person with the knowledge and skills to assess conditions and activities that could impact stormwater quality at the facility, and evaluate the effectiveness of best management practices required by this permit. Retain a copy of the completed and signed form.

Application for State of Washington water quality certification for Hydro Battery Pearl Hill.

Ecology finds Hydro Bioinfiltrator functionally equivalent to a bioretention planter or planter box.

Ecology finds this water decontaminator is functionally equivalent to the catch basin insert for stormwater control. While this product does not meet Washington's water quality performance criteria, it may be used in retrofit or construction situations to provide some level of TSS removal for stormwater.

Irrigation System Aquatic Weed Control NPDES General Permit Fact Sheet and Response to Comments

Irrigation System Aquatic Weed Control NPDES General Permit

Study of aquatic life and migration patterns in the Palouse River.

We issued the Industrial Stormwater General Permit in 2014. This is a National Pollutant Discharge Elimination System (NPDES) and State Waste Discharge General Permit for stormwater discharges associated with industrial activities.

Use this guidance poster to encourage boatyard cleaning instead of underwater cleaning of boats.

Study of aquatic life and migration patterns in the Palouse River.

Sites covered under the Construction Stormwater General Permit (Permit) must take specific reporting and adaptive management actions in order to comply with permit requirements when obtaining high turbidity results (greater than or equal to 250 Nephelometric Turbidity Units (NTUs)) or low transparency results (less than or equal to 6 centimeters).

All Permittees must inspect the construction site and monitor water discharging from the construction site. Inspections must be summarized in an Inspection Report or Checklist and kept with the Site Log Book. These requirements are listed in the CSWGP - S4. Monitoring Requirements, Benchmarks and Reporting Triggers.

Introductory slides for the public meetings in 2017 about the Reissuance of Phase I &Western Washington Phase II Municipal Stormwater Permits.

This agreement between Ecology and the Port of Seattle about Cruise Ships