MTCA Cleanup Regulations (also called the Cleanup Rule) applies to all cleanups, whether they're
upland cleanups on land or in groundwater, or
sediment cleanups in freshwater or marine environments. We published the first Cleanup Rule in 1991 and most recently amended it in 2007. In 2018, we began a multi-year process to update this rule. Learn more at
Chapter 173-340 WAC and
Cleanup Rule exploratory rulemaking.