Colorado municipalities reach multimillion-dollar landfill cleanup deal

Three municipalities in Colorado have reached an agreement on who will pay for the multimillion environmental cleanup at the Larimer County landfill, where contaminants have been leaching into surrounding groundwater and surface water for decades.

The unlined landfill, which was built in the 1960s, has resulted in contaminants from buried waste reaching groundwater and surface water surrounding the 180-acre site between Fort Collins and Loveland. Larimer County, Fort Collins and Loveland co-own the landfill.

According to the Coloradoan, the county has been leading efforts to address the pollution and recently submitted a draft assessment of corrective measures plan to the state in late December. The municipalities made the intergovernmental agreement (IGA) for payment public in December, following a year and a half of discussion.

The IGA directs the county to pay the first $3 million of remediation costs as well as all closure and post-closure expenses. Remediation costs beyond $3 million will be split 60 percent/30 percent/10 percent among the county, Fort Collins and Loveland, respectively. Remediation costs cover the work needed to reverse or stop the environmental damage from the water pollution; closure and post-closure costs are related to covering the landfill, restoring landscaping in the area and managing and monitoring the site after the landfill closes.

Also, as part of the IGA, the city of Fort Collins will start paying tip fees for municipal waste from city departments that it self-hauls to the landfill. The city has historically diverted the equivalent of those unpaid tip fees into an internal Waste Innovation Program that has offset the municipal waste sent to landfills.

Officials from the three municipalities believe the remediation costs are unlikely to be more than $3 million, so it’s possible the two cities will foot little or none of the bill. The total costs associated with closing the landfill, which is expected in 2024, are projected to be in the range of $5 million to $11 million.

Remediation work will progress once the Colorado Department of Public Health and Environment approves the assessment of corrective measures.

Multiple cleanup strategies are being considered, including monitored natural attenuation, which relies on natural processes like evaporation and biodegradation to clean soil and groundwater pollution; groundwater diversion strategies; measures to control the sources of the contaminants; phytoremediation, which involves using plants to absorb and transpire contaminated groundwater; and spot treatments using chemicals.

Several chemicals have been leaching from the landfill, including trachloroethene (abbreviated as PCE) and trichloroethene (TCE), which likely came from degreasing solvents, dry cleaning agents and paint removers that were dumped in the landfill in the 1960s and early 1970s, county staff previously told the Coloradoan. Bacteria slowly breaks down those chemicals, producing dichloroethene, which then breaks down into vinyl chloride—a human carcinogen.

A newer contaminant of concern is 1,4 dioxane, a carcinogenic chemical found in detergent, deodorant, shampoo, cosmetics and other products. Officials discovered 1,4 dioxane contamination in groundwater near the landfill in 2017. The discovery prompted additional state pressure to address the pollution.