This site is one of the "Superfund" hazardous waste sites in Colorado. A site qualifies for the National Priorities List (NPL or Superfund list) when the U.S. Environmental Protection Agency (EPA) determines there is a release or threatened release of hazardous substances that may endanger public health, welfare or the environment. In Colorado, the lead agency for Superfund remediation may be either the EPA or the Colorado Department of Public Health and Environment.
The site is located in the western portion of Montrose County on Highway 141 approximately 13 miles northwest of the Town of Nucla and 81 miles from the Town of Whitewater in Mesa County. The town of Uravan no longer exists. The City of Montrose is 115 miles away, and Grand Junction is located 90 miles to the northeast. The site is located on the bank of the San Miguel River, which drains into the Colorado River.
The site began as a radium recovery plant in 1915 and was expanded to include vanadium recovery in 1935. The plant operated from the 1940's to 1984 as a uranium processing facility. UMETCO, a subsidiary of Dow Chemical, has operated the facility since 1984. The town of Uravan was established in 1935 to house workers and their families at the mill and mine facilities. The town has since been evacuated and demolished. The site was placed on the list of Superfund sites on June 6, 1986.
A complex mixture of chemicals exists at the site. The contaminants include radioactive products including raffinates (liquid wastes from the uranium processing operations), raffinate crystals (primarily ammonium sulfate compounds), and mill tailings containing uranium and radium. Other chemicals in the tailings and groundwater include heavy metals (lead, arsenic, cadmium, vanadium), thorium, and residual salts.
At the time reclamation began, the air at the site contained elevated levels of radon gas from the tailings piles. These materials have since been relocated and placed in covered containment cells. Soil surrounding the mill site and groundwater contained radionuclides and heavy metals. Because no one lives in the town of Uravan and the groundwater is not being utilized, the human health risks are considerably limited.
The State of Colorado completed a plan to cleanup the site in 1986. The cleanup plan was designed to control radon production and the migration of heavy metals, thorium, and residual salts from the site. Remediation included (1) securing nearly 10 million cubic yards of radioactive tailings in a disposal area and capping/revegetating the area; (2) constructing a lined disposal system for the radioactive crystals; (3) placing 1.5 million cubic yards of waste located adjacent to the San Miguel River in a secure disposal area located away from the river; (4) placing contaminated soil in an approved on-site repository; (5) reclaiming and revegetating the land on the site; and (6) collection and treatment of contaminated groundwater.
In March 2000, the US Environmental Protection Agency performed a 5-year review of the site as required by law. The review concluded that remedial actions are being conducted in accordance with the consent decree and remedial action plan, and that the selected remedies remain effective in protecting human health and the environment.
Frances Costanzi, P.E.
EPA Remediation Project Manager