ALBUQUERQUE, N.M. — The New Mexico Supreme Court today affirmed the state’s so-called “copper rule,” ruling that the 2013 regulation provides “significant groundwater protection” at open pit copper mines.
The court ruled unanimously that regulations adopted by the state’s Water Quality Control Commission were valid under the state’s Water Quality Act.
The New Mexico attorney general and other groups, including Amigos Bravos, the Gila Resources Information Project and Turner Ranch Properties, had challenged the regulation.
The regulation dictates how mining companies are required to protect – opponents say allowed to pollute – groundwater where they operate.
“We cannot conclude that the Copper Rule violates the (Water Quality Act) because it purportedly permits rather than prevents contamination when the Cooper Rule’s plain terms contain an abundance of provisions that afford significant groundwater protection at copper mine facilities designed to prevent pollution,” said the opinion written by Chief Justice Judith K. Nakamura.
Supporters of the rule had argued that it strikes a balance and that overturning it could threaten the viability of copper mining in New Mexico.
The rule allows mining companies to exceed water quality standards at mining sites, including open pit operations and waste rock piles, as long as the concentration of contaminants found in monitoring wells around the perimeter of those areas meet water quality standards. Under the rule, pollution standards do not apply at the bottom of the pit, where water gathers in deep open pit mines.