Fort Collins, Larimer County and Loveland have reached an agreement on who will pay millions of dollars for environmental clean-up at the Larimer County landfill, where contaminants have been leaching into surrounding groundwater and surface water for decades.
The landfill was built in the 1960s, before environmental regulations required sanitary linings. As a result, a plume of contaminants from buried waste has reached groundwater and surface water surrounding the 180-acre site between Fort Collins and Loveland. The county, Fort Collins and Loveland co-own the landfill.
Contaminated groundwater and surface water can be a hazard for drinking water supplies, wildlife and irrigated land, but the contaminants of concern haven’t reached any drinking water sources, officials said. They track potential water impacts by sampling groundwater wells that are used for drinking water or stock water in the area.
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 county and cities made the intergovernmental agreement for payment public in December, following a year and a half of discussion.
Representatives of the county, Fort Collins and Loveland provided jointly written answers to Coloradoan questions for this story.
The intergovernmental agreement 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%/30%/10% 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.
The remediation work can’t progress until Colorado’s Department of Public Health and Environment approves the assessment of corrective measures.
Among the cleanup strategies that are being considered: 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.
Two plumes of groundwater contamination stretch off the landfill site and into portions of Fort Collins’ Cathy Fromme Prairie Natural Area. Officials have also found intermittent surface water pollution from the landfill in Fossil Creek and Smith Creek, which run through Cathy Fromme Prairie.
Groundwater at Cathy Fromme Prairie isn’t used for any consumptive purposes. Visitors to that area are expected to stay on trail and away from creeks and streams.
The county upped its efforts to keep hazardous materials out of the landfill in the mid-to-late ’80s, when officials created a household hazardous waste program, started training staff to screen waste for hazardous substances and launched public education campaigns. The county started more extensive searches for landfill contamination around the same time. In 1993, the county built a reinforced concrete wall to prevent contaminated water from leaching into Smith Creek underground.
The county has also been “capping” filled areas of the landfill since the late ‘90s. Capping involves covering areas with compacted clay to prevent rain and snowmelt from percolating through buried waste and creating more groundwater contamination. About 54% of the site has been capped.
Jacy Marmaduke covers government accountability for the Coloradoan. Follow her on Twitter @jacymarmaduke. Support her work and that of other Coloradoan journalists by purchasing a digital subscription today.