Greenacres Landfill

Greenacres Landfill is located in Liberty Lake, WA 99019. The landfill is closed and undergoing clean-up action. The last Ecology Five-Year Review occurred in 2013.

Historic Timeline

Year Occurrences
1967 Ownership of Greenacres Township Municipal Dump given to Spokane County.
1972 Landfill closed.
1978 Ecology detected groundwater contamination in well adjacent to landfill site.
1983 Landfill site nominated for Superfund eligibility.
1984 EPA placed landfill site on National Priorities List (NPL).
1989 Remedial Investigation of site.
1991 Feasibility Study completed.
1994 Enforcement Order given to monitor groundwater at site for three years.
1997 Consent Decree signed by Spokane County to implement a clean-up action.
1998 Landfill cover construction completed.
1999 Post closure monitoring commences.
2001 Final Clean-Up Action Plan commences.
2015 Ongoing monitoring and maintenance continues.

Indicator Substances for Groundwater Monitoring

Type of Indicator
Metals As, Mn, Sb, Cr, Pb

Clean-Up Action Components

System Description
Landfill Cover System
30-millimeter PCV geomembrane layer with active gas extraction system and storm water control.
Gas Extraction System
Landfill gas directed through biofilter system before discharge.
Institutional Controls
Restrictions placed on access to groundwater and land use at site.
Groundwater Compliance Monitoring
Includes a network of 15 groundwater monitoring wells.