The Hidden Valley landfill is a closed 92-acre municipal solid waste landfill located in Puyallup, WA. Pierce County ran the landfill from the mid-1960s until 1977 when LRI bought it. Waste disposed of at the site included solid, demolition, commercial, and industrial waste. LRI stopped disposal in 1998.
| City | Pierce County |
|---|---|
| County | Pierce County |
| State | Washington |
| Coordinates | 47.09500, -122.28780 |
Hidden Valley Landfill Thun Field is a federal Superfund site in Washington. The Superfund program, created by Congress in 1980, addresses sites where hazardous substances have been released or threaten release into the environment. EPA scores potential sites using the Hazard Ranking System; those that score high enough are placed on the National Priorities List.
Current status: Ready for anticipated reuse. EPA considers this site ready for anticipated reuse, meaning cleanup has progressed enough for certain land uses. This does not necessarily mean all contamination has been removed — institutional controls like deed restrictions may limit how the land can be used.
EPA has identified 7 contaminants of concern at this site, including 1,4-dichlorobenzene, chloride, iron. Contamination has been detected in groundwater.
If you live near this site and have health concerns, your state health department can provide site-specific guidance. EPA maintains a community involvement program for most NPL sites, and site documents — including the Record of Decision, five-year reviews, and public health assessments — are typically available through EPA's Superfund site profile.