In Rico, a history of hard-rock mining has left behind dangerous levels of lead on the properties of some residents, prompting a clean-up program expected to begin this spring.
Under supervision from the EPA and the Colorado Department of Public Health and Environment, former mine operator Atlantic Richfield Company conducted soil studies that confirmed high concentrations of lead on private and public land in some areas of this former mining boom town.
“Initial soil samples came back hot, so we had a meeting and knew some-thing had to be done in Rico,” said Mark Walker, project coordinator for the state health department.
That meant securing permission from landowners to collect and test soil samples. To date, 350 property owners, including Dolores County, agreed to the study and have been tested. The remaining 40 property owners have not granted permission for testing.
Soil sampling and removal on private property is not mandatory, Walker said, but is strongly recommended because of the possible health hazard.
“The mineralized veins where the ore was mined are close to the surface so the chances of coming in contact with it are pretty good,” he said.
According to a report of the sample findings, there are significant hot spots of lead contamination in and around town. Walker said a safe lead concentration has yet to be determined for the area but that sites with samples above 3,000 parts per million are a “no-doubter, and should be cleaned up as soon as possible.”
In one test within town near tailing piles, lead concentration spiked at 86,600 ppm, at least 40 times higher than levels considered safe. Other results showed 32,400 ppm of lead in a soil sample taken from property along the river corridor, and a city street sample showed 32,400 ppm of lead concentration.
Properties that show a level below 3,000 ppm will be recommended for clean-up but that exact number is still being decided on, Walker said.
Too much exposure to lead can damage the nervous system, kidneys and reproductive system, according to the Agency for Toxic Substances and Disease Registry. Children are especially susceptible to lead poisoning in soil, such as from mine tailings, where they may play. Concerned, the town received state funding to test children for high levels of lead. Town officials reported last month that the blood tests returned within normal levels.
The soil studies were done under a voluntary program monitored by the CDPHE and EPA in cooperation with Atlantic Richfield, real-estate companies Rico Renaissance and Rico Properties, Dolores County and the Town of Rico.
The next phase is the voluntary clean-up, where the first 12 inches of topsoil are removed from contaminated property and then stored in a repository proposed for construction less than one mile north of town.
If approved by Dolores County, the contaminated-soil storage facility will be built on land owned by Rico Renaissance at the base of the St. Louis Mine.
According to published plans, the four-acre site is located outside the 100-year floodplain. It will be lined and will channel drainage into the 18 settling ponds that already collect and filter heavy-metal runoff from the abandoned mine tunnels, before flowing into the adjacent Dolores River.
The waste-storage facility, designed and constructed by ARCO, will have a capacity of 40,000 cubic yards. It will take three years to fill and will have a 30-year lifespan. The collected soil will be compacted, capped and vegetated to avoid wind erosion.
If approved, the facility will be built in time to begin receiving contaminated soil this summer, Walker said. Clean-up is free to landowners, and all soil removed will be replaced with fresh fill.
