You can use an address to look up your watershed, also known as a Water Resource Inventory Area (WRIA). We typically study and regulate water resources by WRIAs. There are 62 WRIAs in Washington.

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Ocean acidification is a global problem with local impacts. The impact of greenhouse gases on rising temperatures, coupled with excess nutrients from nitrogen and carbon, can hinder healthy aquatic ...

EIM Data Analysis Tool (EDAT) is an analysis tool for Model Toxics Control Act (MTCA) practitioners and other contamination cleanup professionals. It compares Washington State environmental monitoring ...

CLARC February 2025 updates are now online. We made updates to incorporate newly published IRIS toxicity values for arsenic and PFHxS and associated noncancer effects information. We also updated ...

Puget Sound is critical to our environment, culture, and economy. About two-thirds of the state’s population lives in the Puget Sound region. Our nation’s second largest marine estuary faces a number ...

This legal designation establishes the boundaries for a future groundwater co-management agreement in the Pasco Basin between state and federal water managers. In July 2022, we set in motion a new ...

Complying with the Clean Fuel Standard (CFS) includes registering with Ecology, reporting fuel sales, paying an annual fee, and purchasing credits if you’re a deficit holder. Under the CFS, ...