The City and County of Denver has compiled brief answers to the most frequently asked questions about the Lowry Landfill Superfund site. Click below to see the answers to citizens’ most popular inquiries. If you have further questions, please contact us.
Lowry Landfill is located near the intersection of Quincy Avenue and Gun Club Road in Arapahoe County, 15 miles southeast of downtown Denver. From 1965 until 1980, it accepted municipal and liquid industrial waste from businesses and residences in the Denver metro area. The 507-acre site was declared a Superfund site in 1984, when the U.S. Environmental Protection Agency placed it on its National Priorities List. Since then, those responsible for contamination—including private businesses, municipalities, and state and federal agencies—have paid for environmental studies and cleanup in excess of $100 million.
No. Lowry Landfill generally stopped receiving municipal solid waste in 1990. The only exceptions today are asbestos, which is still disposed of at the site, and inert building materials, which have been authorized for disposal specifically to improve the slope of the current landfill cover. If you live in the Denver metro area, it is very likely that your household waste ends up at the Denver Arapahoe Disposal Site, a fully permitted, state-of-the-art, non-hazardous municipal solid waste facility located adjacent to Lowry Landfill, but not part of it.
In the last century, few people understood how certain wastes might affect people’s health and the environment. As a result, dangerous materials were dumped onto the ground, into rivers or left out in the open. Hazardous wastes accumulated in vacant lots, at factories, warehouses, landfills and dumps across the United States. Among the most pressing problems were wastes that leached down through the ground to contaminate drinking-water supplies.
In response to growing concern about health and environmental risks posed by these pollutants, Congress established the “Superfund” program in 1980 to clean up waste sites. Administered by the U.S. Environmental Protection Agency in cooperation with individual states and tribal governments, Superfund locates, investigates and cleans up hazardous-waste sites throughout the country—including Lowry Landfill, which was placed on the U.S. Environmental Protection Agency’s National Priorities List of Superfund sites in 1984.
Lowry Landfill qualified for Superfund status because of groundwater contamination resulting from the legal disposal at the site of municipal solid waste and an estimated 138 million gallons of liquid waste. Although disposal methods complied with the environmental regulations in effect at the time, the U.S. Environmental Protection Agency determined that the liquid waste had contaminated the soil and groundwater beneath the site, and could cause further environmental damage if it migrated beyond it.
The cleanup plan at Lowry Landfill is designed to protect the surrounding environment and human health by preventing contaminants from moving off the site and by preventing human exposure to landfill gas, waste-pit liquids and contaminated groundwater. This “containment” approach is commonly used at contaminated municipal landfills because the risks involved in removing and transferring large volumes of materials elsewhere are greater than the risks of managing the wastes onsite. The containment approach at Lowry Landfill consists of multiple components, including a clay cap on top of the landfill mass; underground barrier walls designed to prevent groundwater from flowing on and off the site; a state-of-the-art onsite water treatment plant; and a gas-to-energy system that converts landfill gases into energy. There is also a groundwater monitoring system at the site to track the movement of contaminated groundwater (i.e., water that flows underground).
The primary focus of cleanup at Lowry Landfill has been to safely contain, collect and treat groundwater at the site. Water pumped from the ground is treated in an onsite water treatment plant, then pumped to the Metro Wastewater Reclamation District and Aurora’s wastewater treatment facilities for further treatment before being discharged. Both onsite treated water and discharge from the Metro and Aurora facilities must meet strict discharge standards and are routinely tested to assure continued compliance. A portion of Aurora’s and Metro’s wastewater is processed through water recycle plants and used for irrigation at parks and golf courses, and as water supply for park lakes. For more information, consult Denver Water and Aurora Water.
The federal government deeded the site to the City and County of Denver in 1964 for use as a landfill. Denver, which still owns the site, operated Lowry Landfill there from 1965 until 1980, at which point Waste Management took over the landfill’s operations. Under a settlement among the hundreds of entities that at one time used Lowry Landfill as an industrial disposal site, Denver and Waste Management agreed to manage the site’s cleanup together.
Denver and Waste Management spent more than two decades investigating the site; researching cleanup options; and designing, implementing and fine-tuning a successful cleanup approach using the latest and most effective environmental technologies available.
Today, the many components that comprise cleanup at Lowry Landfill are in place and certified complete by the appropriate regulatory agencies. Most of the site is now in “operation and maintenance” mode, meaning the monitoring and treatment of groundwater and landfill gas will continue until the groundwater is returned to drinking water, background or ambient standards, and until landfill gas is no longer generated at quantities that need to be controlled. Adjustments to remedy components will be made as necessary and as new and better technologies become available.
The 1,4-dioxane investigation described in the “North End Monitoring and Response Action” section of this website is considered part of the overall remedy and will also continue until the same drinking water, background or ambient standards are achieved.
As in most landfills, there are medical wastes, smoke detectors and other items at Lowry Landfill that contain small amounts of radioactive material. However, studies show that overall radioactive material at Lowry Landfill is present at background levels that are consistent with naturally occurring and manmade radiation found throughout the western United States. Furthermore, after years of investigations and analyses of thousands of groundwater samples, the Inspector General for the U.S. Environmental Protection Agency issued a formal report in 2000 that found “no apparent credible evidence” that manmade radioactive materials such as plutonium were ever disposed of at Lowry Landfill.
For more information, review the U.S. Environmental Protection Agency’s “Radionuclides and the Lowry Landfill Superfund Site” fact sheet.
The site never accepted any unexploded ordnance from the Former Lowry Bombing and Gunnery Range, the Rocky Mountain Arsenal or any other military facilities. The only wastes accepted from the former nuclear weapons facility at Rocky Flats were non-radioactive solvents and construction debris.
There is no current human health risk at Lowry Landfill because nobody is being exposed to site-related contamination. Because wastes will remain on the Lowry Landfill site, the U.S. Environmental Protection Agency by law conducts mandatory five-year reviews to ensure all containment activities are working as designed. The latest five-year review, completed in September 2012, confirmed that the remedy is “functioning as intended” and “protective of human health and the environment.” The U.S. Environmental Protection Agency also has declared that the 1,4-dioxane detected north of the Lowry Landfill site boundary does not present a threat to people living in the vicinity.
Since 1984, groundwater with contamination exceeding state standards has been detected by the monitoring system outside the site’s point of compliance to the east and west. Although it is unclear whether this contamination “left the site” or was already outside the point of compliance when cleanup was initiated, measures have been taken to contain this contamination and keep it under constant monitoring.
In 2007, contaminated groundwater was found outside the site boundary to the north. An investigation was conducted to determine the origin of this contamination and its extent. This investigation concluded that only shallow groundwater (less than 50 feet deep) is impacted and that its reach is limited to a narrow band beneath the old Murphy Creek drainage for approximately 2.4 miles north of the site boundary. Efforts also are underway to minimize contaminant migration northward by extracting contaminated groundwater from wells and treating it in an onsite water treatment plant.
Because wastes will remain on the Lowry Landfill site, the U.S. Environmental Protection Agency will continue to conduct mandatory five-year reviews to ensure all containment activities are working as designed. In addition, groundwater at the site will continue to be monitored.
As an extra measure of protection, Lowry Landfill’s owners and operators have voluntarily purchased properties within a half-mile of the site. As a result, future groundwater use will be prohibited and future land use controlled.
Although there are no immediate plans for the land on or around the site, any future development will complement cleanup efforts, conform to established restrictions, and comply with all public health, safety and environmental regulations.
14. Is funding available to educate citizens about the technical aspects of the Lowry Landfill cleanup?
Yes. The U.S. Environmental Protection Agency awards Technical Assistance Grants (TAGs) to citizen groups affected by Superfund sites to help them understand and be involved with site-related decisions. One TAG, for instance, was awarded to an organization called Citizens for Lowry Landfill Environmental Action Now (CLLEAN).
Those wishing to learn more about the TAG may contact Katherine Jenkins, Public Affairs Specialist, 303.312.6351 (office), 720.930.0842 (cell) or Jenkins.email@example.com
Those wishing to learn more about CLLEAN may contact the organization’s director, Bonnie Rader, at (303) 364-2905 or firstname.lastname@example.org.