Colorado Environmental

The State Of Colorado Settled A Water Contamination Lawsuit For Natural-Resource Damages

In 1958, the Cotter Corporation began milling uranium ore outside Canon City, Colorado. Mill operations released radionuclides (radioactive particles) and metals into the environment, causing soil contamination around the mill itself, as well as ground-water contamination in the nearby community of Lincoln Park.

Cotter has been cleaning up the contamination, under a radioactive-materials license and a court settlement with the State of Colorado, as well as with EPA oversight. The company resumed milling operations in May 1999.

Lincoln Park is a semi-rural community, two miles south of Canon City, about 1.5 miles from the Cotter uranium mill. Many of the residents have gardens and orchards. Some raise livestock. The mill is in the Sand Creek drainage, which flows through Lincoln Park to the Arkansas River.

Before 1980, Cotter disposed of tailings and other wastes from uranium processing into unlined ponds, following the custom of the times. Contaminants leached into ground water, then migrated to Lincoln Park, affecting local wells. Few residents use ground water for domestic purposes. Most are connected to the Canon City water supply. Some individuals in Lincoln Park still use ground water to irrigate lawns and gardens.
 
Wind deposited contaminants on soils adjacent to the mill. Tailings, the waste from ore processing, were carried in surface water runoff from the mill, contaminating the stream sediments in Lincoln Park's Sand Creek.

The contaminants of concern at the site are molybdenum and uranium. Repeated exposure to molybdenum can cause increased uric acid accompanied by gout-like symptoms. In cud-chewing animals eating feed low in copper, molybdenum poisoning can be severe. Uranium is a radioactive metal. It occurs naturally in most rocks and soil. In its natural state, it has low levels of radioactivity. If swallowed, it can be toxic to the kidneys. Uranium breaks down or "decays" very slowly. It decays to radium through a series of chemical and radiological changes. Radon gas is one of the decay products.

LINCOLN PARK LISTED CLEANUP

The Lincoln Park site was added to the Superfund National Priorities List in 1984. In 1988, the State of Colorado settled a lawsuit for natural-resource damages with Cotter. As part of the settlement, the State and Cotter agreed on how the site would be cleaned up further at Cotter's expense. EPA and the State also signed a Memorandum of Understanding (MOU) giving the State the lead role in overseeing the cleanup of the site. Cleanup activities since 1988 have included:
Connecting Lincoln Park residents to city water if they chose;

Constructing a ground-water barrier at the Soil Conservation Service dam to minimize migration of contaminated ground water into Lincoln Park;
Moving contaminated soils into a lined impoundment;
Flushing and chemically fixing contaminants in the Old Pond area; and
Constructing a permeable reactive treatment wall to remove uranium and molybdenum from the ground water.

Cotter also voluntarily cleaned up several railroad loading areas around Canon City, where uranium ore and other materials had been spilled. In addition, the company conducted soil, vegetation and sediment sampling and upgraded its ground-water monitoring program.

While waiting for a license amendment that allowed them to begin new milling operations, Cotter upgraded air quality control systems and made other environmental improvements at the mill. The radioactive-materials license amendment that authorized retooling for the mill became effective in February 1997. Mill operation resumed, with modified alkaline-leaching capability, in May 1999.

Cleanup and monitoring under the Remedial Action plan continue with State oversight. In January 2002, EPA issued a Record of Decision (PDF file) requiring No Further Action for surface soils within Lincoln Park. This decision was made because previous surface-soil cleanup activities have eliminated or reduced risks to acceptable levels. However, there has been other activity involving the Cotter uranium milling facility since that time.

The Lincoln Park site is divided into two major cleanup areas, called Operable Units. OU1 is the Cotter milling facility itself, located about three miles from downtown Canon City. The Cotter mill wants to receive, reprocess, and/or store 470,000 tons of waste soils from a Superfund site in Maywood, New Jersey, as well as waste from the Li Tungsten Superfund site in New York. The Maywood and Li Tungsten wastes are low-(radio)activity tailings mixed with soil containing thorium and radium at low concentrations. The material is to be shipped to the Cotter facility by rail.