Contaminated Sites

The release of a hazardous substance can result in significant harm to human health or the environment. The Washington State Department of Ecology’s Toxics Cleanup Program conducts site investigations of non-emergency hazardous substance releases to the environment. These site investigations are defined as “Initial Investigations” within Washington State’s Model Toxic Control Act (MTCA). MTCA is a citizen-mandated toxic waste cleanup law (Initiative 97) that went into effect in March 1989 and was written to be protective of both soil and groundwater.

Click here for a link to the MTCA Statute (Chapter 70.105D RCW) and Regulation (Chapter 173-340 WAC):

Site investigations can be generated by self-reporting, or by a complaint filed with the Washington State Department of Ecology. Any property/facility owner or operator who has information that a hazardous substance has been released to the environment at their property, which may be a threat to human health or the environment, must report the release to Ecology. Early reporting and intervention minimizes the impact to public health and the environment, and can minimize the spread of hazardous substances through the environment and the subsequent cost of cleaning it up.

REPORTING REQUIREMENTS: Confirmed releases from underground storage tanks must be reported to Ecology within 24 hours of discovery. Confirmed releases from sources other than underground storage tanks must be reported within 90 days of discovery. It is recommended that all confirmed releases be reported to Ecology within 24 hours of discovery.

Report a spill here:

Information regarding the major steps in the cleanup process can also be found here: *Note:  Underground Storage Tank (UST) Removal and UST Site Remediation continues to be subject to Health Department oversight.  Please click here for more information about our UST Program.

Related Links:

Selecting a cleanup contractor:

Guide for homeowners and small businesses:

Hazardous waste considerations in real estate transactions:

Site Lists:

Heating oil tank insurance: