By Alan Prendergast
By Michael Roberts
By Michael Roberts
By Amber Taufen
By Patricia Calhoun
By William Breathes
By Michael Roberts
By Melanie Asmar
Lowry Landfill was a dumping ground for city and commercial waste between 1966 and 1980. Located near Aurora, the Denver-owned, 480-acre former landfill contains acid sludge, petroleum-based oils, pesticides, paint, varnish, sewage sludge and hospital waste, some of which has seeped into the groundwater. The EPA placed Lowry on the NPL in 1984. More than 200 companies and municipalities have since been identified as polluters, including Coors, Conoco, IBM, Gates Rubber Company, the City of Lakewood, Syntex Chemicals Inc. and Shattuck Chemical Company. The EPA estimates cleanup will be done in 2003.
Marshall Landfillonce posed a threat to the drinking supply of Louisville residents, but since the site was placed on the NPL in 1983, the problems have been solved. The landfill, located about three miles southeast of Boulder, had leached contaminants into a ditch that carried drinking water from the Marshall Reservoir to Louisville. Between 1965 and 1974, the landfill accepted septic waste, sewage sludge and unidentified hazardous wastes. Benzene, trichloroethylene (TCE) and barium were just some of the dangerous pollutants found in the surface- and groundwater. The parties mainly responsible for the contamination -- the City of Boulder, Browning-Ferris Industries (now owned by Allied Waste Industries) and Cowdrey Corporation -- agreed to pay for the cleanup and to build and operate a water-treatment plant. The contamination has been cleaned up, but the site won't be taken off the NPL until groundwater standards are met.
Rocky Flatsis doubtless Colorado's most notorious Superfund site. In 1952, the United States Department of Energy started making plutonium for use in nuclear weapons at this flat spot near the foothills northwest of Denver. The EPA and the FBI shut down Rocky Flats in 1989 for environmental violations, and three years later, after the Cold War ended, the government decided not to resume the production of nuclear-weapons parts at Rocky Flats. But the damage had been done. Liquid plutonium stored in leaky drums, unlined disposal trenches, seeping underground tanks and on-site landfills left much of the soil and groundwater at the 300-acre industrial area contaminated. Other radioactive elements such as uranium and americium have also been discovered in the soil. In 1999, the first shipments of waste were transported from Rocky Flats to a waste isolation plant in New Mexico, and later, more waste was transferred to Nevada. The cleanup effort is expected to continue until 2007.
Rocky Mountain Arsenal was established by the United States Army in 1942 to produce weapons during World War II. Over the next three years, the arsenal made 155,000 tons of chlorine, mustard gas and arsenic trioxide, in addition to 87,000 tons of other chemical products. Following the war, the arsenal leased parts of the 17,000-acre property to companies such as Colorado Fuel and Iron, which made chemicals there; Julius Hyman and Company, which manufactured pesticides; and Shell Oil Company, which produced pesticides, insecticides and herbicides at the arsenal until 1982. The Army and the private companies improperly disposed of waste, leaving behind tainted groundwater. The arsenal was placed on the NPL in 1987, and Congress later passed a law designating the arsenal as a National Wildlife Refuge when the cleanup is complete in 2011.
Summitville, in the San Juan Mountains of southwestern Colorado, was a gold mine that leaked cyanide and acidic and metallic water into the Alamosa River. The contamination killed the aquatic life and got into the irrigation waters that serve the farmland downstream. Summitville had been mined off and on since the 1870s; in the 1980s, Summitville Consolidated Mining Company took over until 1992, when it declared bankruptcy. That year, the EPA stepped in to prevent a catastrophic overflow of cyanide-laden water from seeping into the river; two years after that emergency remediation, the EPA placed Summitville on the NPL. Although the cleanup was expected to have been complete by 2004, the EPA recently announced that it may actually take a century or more.
Uravan Uranium was originally a radium-recovery plant in the early 1900s, but this site in Montrose County was later converted to a uranium- and vanadium-processing facility until it closed in 1984. Radioactive waste from the site, which was operated by Union Carbide, contaminated the air, soil and groundwater around the 450-acre plant, as well as the San Miguel River. Uravan Uranium was added to the NPL in 1986. Umetco, a subsidiary of Union Carbide, is paying for the cleanup, which should be done in 2005.
Vasquez Boulevard and I-70 includes parts of the northeast Denver neighborhoods of Elyria, Swansea, Cole and Globeville. The area was the site of three smelting plants -- the Globe, Argo and Omaha-Grant -- which began refining gold, silver, copper, lead and zinc in the 1870s; the Globe plant still operates. Soil samples in residential yards showed high levels of arsenic and lead, so in 1998, the EPA removed soil outside eighteen homes; the area was placed on the NPL in 1999 and will likely remain a Superfund site until at least 2005.