Closed Municipal Solid Waste Landfills Initiative

Closed landfills used for trash (municipal solid waste) disposal in Colorado, some of which were closed decades ago, can present risks to human health and the environment. 
  • Some closed landfills were inadequately designed and capped. 
  • Some closed landfills are not well maintained and cap erosion and illegal dumping become problems. 
  • Nearby development pressures and utility corridor issues can impact closed landfills, increasing ground water and landfill gas migration concerns. 
A large number of these closed landfills ended operations between the late 1980s and mid-1990s. These operations ended because many landfills could not cost-effectively comply with federal landfill regulations that became effective in 1993 (see Figure 3 of the draft scoping document below). Since the early '90s, a small number have closed as they reached capacity and waste disposal shifted to new landfills.
We are embarking on a state-wide initiative to work with local governments, waste management companies and other stakeholders to:
  1. Carefully inventory all landfills that closed after 1967 (the date that the Colorado Solid Waste Act passed).
  2. Evaluate the state of the landfill and whether it was adequately closed and presents low risk to people and the environment.
  3. Place the landfill under the appropriate regulatory control going forward.
To begin this initiative, CDPHE, with input from stakeholders, has developed the Scoping Document available below:
Closed Landfill Initiative flow chart
A user friendly flow chart to determine which closed landfills will be considered in this initiative.
Closed Landfill Initiative list
This list of closed landfills across the state is a continuing work in progress and will be periodically updated.
This timeline is provided for summary purposes.
If you want to provide comments or input on any aspect of the Closed Landfill Initiative, please email:
David Snapp