The Sierra Club on Thursday filed a lawsuit in Maricopa County Superior Court challenging Arizona regulators’ decision allowing UNS Electric to expand its gas-fired Black Mountain Generating Station without obtaining a certificate of environmental compatibility.
The decision “overturned the existing environmental review process for gas plants that has been followed for decades, setting a dangerous precedent,” Sierra Club Grand Canyon Chapter Director Sandy Bahr said in a statement.
The Arizona Corporation Commission voted in June to authorize a 200-MW expansion of the plant, ruling that because each of the individual planned units are under 100 MW, the commission “does not have mandatory jurisdiction.” State law requires a certificate of environmental compatibility for power plant additions of 100 MW or more, but UNSE plans to add four gas-fired units each with a nameplate capacity of 50 MW.
“Under the commission’s unprecedented decision, no gas-fired power plant over 100 MW would require a certificate, no matter how large the plant,” Sierra Club said in a statement. “This would exempt most large gas-fired power plants being built in Arizona today from any environmental review by the commission, as larger plants typically consist of multiple smaller units.”
The ACC’s decision overturned an order by the Power Plant and Transmission Line Siting Committee that exerted jurisdiction over the proposed expansion.
“It’s up to the Superior Court to correct the Commission’s catastrophic decision that would have detrimental impacts for our air, our water, and our communities,” Bahr said.
The ACC did not respond to a request for comment. Following its June decision, the commission issued a statement noting that “to be clear, in this decision, the commission is not exempting UNS Electric, Inc., or any other utility, from environmental review.”
