Please contact the Site Lead for the most up-to-date status of this site.
James Staley, StaleyJ1@Michigan.gov, (231)-429-1945
Please note that this landfill is CLOSED and does not accept waste.
Mason County Sanitary Landfill, located near 600 West 1st Street, was used as the unlined Scottville Dump as early as the 1940's to the late 1970's. In 1978 the landfill was first licensed. In the late 1980's and early 1990's, groundwater sampling indicated that the dump areas and associated solid waste disposal activities had resulted in groundwater impacts by dissolved metals and volatile organic compounds. These groundwater impacts resulted in the State of Michigan and Mason County entering a Consent Order in 1992 to address the groundwater contamination.
Between 1990 and 1992, two unlined dump areas were relocated to the lined landfill. The lined landfill was capped with clay and closed in 1993. In 1995, two additional unlined dump areas were consolidated and capped with clay. Groundwater monitoring at the site is ongoing and occurs on a semi-annual basis.
Based on the presence of ongoing groundwater contamination from chemicals other than PFAS, in January 2023 EGLE requested that select groundwater wells be sampled for PFAS. PFAS sampling was conducted in April 2023. While numerous wells contained detectable concentrations of various PFAS constituents, monitoring wells MW-13S, MW-16S and MW-16M exceeded groundwater criteria for PFOA, with MW-13S having the highest concentration of 120 ppt.
In a September 2023 letter, EGLE approved a work plan to conduct additional sampling to determine the horizontal and vertical extent of PFAS groundwater impacts at the landfill. The additional sampling was conducted in November 2023. Of the eight monitoring wells sampled, only MW-5 exceeded groundwater criteria for PFOA with a concentration of 10 ppt. All other wells were below criteria and/or did not detect any PFAs constituents. Based on the November 2023 sampling, EGLE determined that PFAS constituents have been adequately delineated at the landfill.
Groundwater flow direction is to the south-southeast toward the Pere Marquette River. Groundwater is likely intercepted by the Pere Marquette River.
Content updated March 2024.
EGLE, DHHS, and local health evaluated the presence of nearby residential wells, and no sampling is planned at this time
EGLE intends to request that monitoring wells MW-5, MW-13S, and MW-16S be sampled for PFAS annually to monitor changes in concentration over time. EGLE also intends on requesting that MW-17S also be sampled annually for PFAS to serve as a downgradient sentinel well to monitor for PFAS migration.
