Oil company agrees to clean up historic lead contamination in settlement with small Colorado mining town

Colorado’s rich and troubled mining legacy can lead to tunnel blowouts, dead rivers and Superfund mandates, making a new cleanup settlement in the tiny southwestern town of Rico sound placid by comparison.  

Rico and state officials Wednesday announced a complex deal with Atlantic Richfield Co., now a subsidiary of giant BP America, to finish digging lead-contaminated soil from yardsand paving over lead-tainted roadways over the next few years. The agreement allows Atlantic Richfield to avoid the imposition of an EPA-forced town cleanup, and Rico is assured the voluntary cleanup is paid for by the company and eases lingering worries about lead in the local soil. 

“It’s a complex project,” said Nicole Pieterse, mayor of Rico since 2021 and a member of local lead action efforts since 2017. “So it has been, I wouldn’t say a struggle, but it has been a tremendous amount of work for the town to put this program in place.” 

Rico, with a population of about 300, sits at an elevation of more than 8,800 feet amid mining properties in the San Juan Mountains. Atlantic Richfield acquired a lead and silver mining operation dormant since the 1970s, the Argentine complex, including the St. Louis Tunnel that has frequently threatened to blow out excess tainted water into the Dolores River. 

Atlantic Richfield has also worked for years cleaning up the water and other waste from the mine to protect the Dolores and local wildlife. The town has natural lead background levels, but acquired more lead when mine waste was used as building fill or road material, or when trucks dragged dust through town. 

A town land use ordinance adopted this month, along with agreements with Atlantic Richfield and the Colorado Department of Public Health and Environment, reduces allowed soil lead levels since a first round of about 74 home yards were dug up and remediated in recent years. The voluntary agreement will clean up existing yards that test above those levels, and test and remediate newly developed parcels. Tainted roadways will be dug up and paved, likely in summer of 2026, Pieterse said, during Rico’s short construction season. 

The multiparty agreements allow Rico to keep control of the cleanup while avoiding overly disrupting the town’s spectacular views, Pieterse said. A separate agreement between Rico and the state calls for ongoing CDPHE enforcement of the pacts regardless of changes in Rico government. 

CDPHE hazardous waste division director Tracie White said the new deals will protect Rico public health. 

“We’re happy to see stakeholders joining together to voluntarily address historic soil contamination in a way that meets the needs of the town and its residents,” White said, in a release accompanying the announcement. 

Contamination levels in Rico have always varied by property, Pieterse said. Her family’s home yard did not test above previous remediation levels and will now be retested under the tougher standard. But a former railroad property they acquired next door will likely need work done when it is redeveloped, she said. 

Of the dozens of home yards remediated in a previous round, Pieterse said, some will need to be retested and may have to be done again. Atlantic Richfield puts the removed soil into a repository it operates north of the town, Pieterse said.

Atlantic Richfield officials “have been really good to work with,” Pieterse said. “They are a large company. There was a lot of reticence about that. There were people who were asking, well, if it’s such a big problem, why hasn’t the EPA come in and dealt with this?

“Well, the EPA is slower than the private sector, No. 1,” Pieterse said. “No. 2, the EPA is watching this very closely, and they were staying out of the way to allow this voluntary process to go forward, and it’s a much better process, because it gives the town a real seat at the table.”