Inactive and Closed Solid Waste Landfills

Inactive Landfill

When a landfill operator fills the landfill with waste to the depth and extent approved by the department, the operator stops accepting waste and begins the landfill closure process. At this point, the landfill is classified as "inactive". The landfill operator must complete certain closure requirements before the landfill is classified as “closed”. Closure requirements may differ between sites, depending on the type of landfill, when the landfill operated and when it stopped accepting waste. In general, the landfill owner or operator must install a final physical barrier, called a cap, over the waste to reduce rain, snow melt and other water sources from soaking into the waste below and producing leachate. Caps on sanitary and demolition landfills help minimize landfill gas production and reduce the amount of leachate produced. The current requirements for landfill closure are described in the department’s guidance document, Landfill Closure Guidance - PUB0187.

Closed Landfill

Once the landfill passes its closure inspection and all closure documentation has been approved, the landfill is classified as "closed". From this point forward, the landfill is in a post-closure care period for as long as the waste remains in place. Like closure requirements, post-closure requirements may differ between sites, depending on the type of landfill, site-specific conditions or corrective actions required by an administrative order or court order and when the landfill stopped accepting waste. The landfill owner or operator continues to perform landfill maintenance, and possibly long-term monitoring if environmental control systems are present, to protect the landfill's vegetative and soil cap and ensure that no leachate or decomposition gases leave the property.

After closure, the department continues to inspect the landfill and maintain contact with the party responsible for the landfill’s maintenance and monitoring. Several guidance documents regarding landfill maintenance and monitoring are available on the department's Solid Waste Landfill Guidance Documents and Fact Sheets webpage. Three fact sheets address landfill maintenance by the owner or operator:

• Requirements and Considerations When Selling or Buying a Landfill - PUB2429
• Maintaining a Closed Landfill - PUB2431
• Acceptable Uses of a Closed Landfill - PUB2430

List of Inactive and Closed Landfills

Listed below are the inactive and closed solid waste landfills located in Missouri, sorted by the county in which they operated. More information about the facility is available in the Missouri Solid Waste Management interactive map. Click on the "expand" tab in the bottom center of the map screen for a table listing all solid waste facilities in Missouri. If you have questions about a specific landfill, please contact the department’s Waste Management Program.

*Also available is a list of operating solid waste landfills in Missouri.

Note: If you are searching for specific information about the Bridgeton Landfill subsurface oxidation event and sampling and monitoring activities that have occurred at the landfill, please visit Bridgeton Sanitary Landfill.