HELENA — A judge says BP-owned Atlantic Richfield Co. must pay nearly $29 million for the cleanup of arsenic that is threatening the groundwater under a Montana town.
That amount includes $1 million for misleading federal environmental regulators and letting another company take full blame.
U.S. District Judge Dana Christensen made the ruling Tuesday in the cleanup of a former smelter in East Helena that is now a Superfund site.
A groundwater plume containing high levels of arsenic and selenium is spreading from the site toward the town of about 2,000.
ASARCO, the smelter owner formerly known as the American Smelting and Refining Company, has paid $111.4 million to date for the groundwater cleanup.
Christensen’s ruling says Atlantic Richfield, which ran a zinc extraction plant at the site, is responsible for 25 percent of that amount.