The 10th Circuit Court of Appeals ruled the federal government should bear some liability for a New Mexico Superfund site located on national forest lands. In a unanimous 3-0 decision on Wednesday, the appeals court in Denver agreed with Chevron, the last operator of the now-closed Questa Mine in the Sangre de Cristo Mountains of northern New Mexico.
The Questa Mine began operations in 1920 just north of Taos, New Mexico. The huge mountain of mine tailings is closer to the small town of Questa which sits along the Red River.
The mine was formerly operated by Molycorp. Inc. and sits on three square miles of land. Open pit mining of molybdenum took place in 1965 and continued until 1983.
Chevron argued that the government met the definition of “owner” and could be found to be a partially responsible party since it had title to the public lands and should be required to help pay for the remediation.
Chevron also revealed the government’s role of encouraging mining at the site in the 1950s by supplying an office to finance mineral extraction that would support national defense. Chevron alleged the government gave Molycorp a loan for molybdenum exploration in order to use the mineral for military-grade steel.
The court did not rule on the government’s actual liability and remanded the case to a lower court for further handling.
The U.S. Environmental Protection Agency says the Questa mining operations placed over 328 million tons of acid-generating waste rock into nine piles surrounding the open pit. It also disposed of more than 100 million tons of tailings in the tailing ponds. The mining operations and waste disposal practices also contaminated soil, sediment, surface water and groundwater.
Chevron estimates cleanup costs will total nearly $1 billion.
