Mayes challenges Arizona power plant's exemption from environmental review

Attorney General Kris Mayes and two environmental groups filed lawsuits challenging the Arizona Corporation Commission’s controversial decision to exempt a 200-megawatt power plant expansion from environmental review.

In June, Republican commissioners voted to overturn a ruling by the commission’s Power Plant and Line Siting Committee that required UniSource Energy to obtain a certificate of environmental compatibility for the expansion of its existing gas plant in Mohave County.

Months earlier, that committee voted 9-2 to deny UniSource’s attempt to exempt the Black Mountain expansion project from that review, citing a state law that requires utilities to obtain a certificate of environmental compatibility before building power plants larger than 100 megawatts.

But the commission found that because the Black Mountain project will be made up of four individual 50-megawatt units, that law does not apply.

At issue is the exact wording of the law that was passed by the state Legislature five decades ago, which defines a plant subject to environmental review as a “separate thermal electric, nuclear or hydroelectric generating unit with a nameplate rating of one hundred megawatts or more.”

In public hearings, Unisource attorneys pointed to that language to defend the position that the Black Mountain project should be exempt from the law, because each of its separate units has a nameplate rating below the 100 megawatt threshold.

Corporation Commission attorney Tom Van Flein provided commissioners with a similar interpretation of the law ahead of the June vote, arguing the state legislature would have to change the language of the law to provide for a different outcome.

“The Commission followed the letter of the law as written,” Van Flein said in a statement provided in response to Mayes’ lawsuit. “Policy advocates wanted a different interpretation for policy reasons. That remains the purview of the Legislature.”

The Sierra Club, Western Resource Advocates and Adam Stafford, an assistant attorney general who chairs the line siting committee, all asked the Corporation Commission to reconsider the case.

But those requests were ignored, prompting Mayes and the two environmental groups to challenge the ruling in Maricopa County Superior Court.

Mayes, a former corporation commissioner, argued the commission’s interpretation of the law overturns decades of precedent, contradicting the way the Corporation Commission has interpreted the statute since it was passed in 1971.

“The Commission’s ruling misinterprets long-standing laws and creates dangerous loopholes,” Mayes said in a statement. “Arizona’s energy projects must remain accountable under the law in order to protect communities and our environment.”

Western Resource Advocates made a similar argument, citing six cases in which the commission’s Line Siting committee required large plants made up of multiple smaller units to undergo the environmental review process. That includes SRP’s expansion of its Coolidge gas plant, which the commission voted on just last year.

Critics also argued the new interpretation of the law also defies common sense.

“Under the Commission’s interpretation, a CEC would be required for a power plant with one thermal electric generator with a nameplate rating of 100 MW or more but would not be required for a power plant comprised of generators with individual nameplate ratings less than 100 MW, but with an aggregate nameplate rating of 1,000 MW, 5,000 MW, or 10,000 MW,” according to the Attorney General’s complaint.

That complaint also noted that the four new generators at the Black Canyon facility could not operate independently of one another.

“Concerningly, the Commission chose to ignore that the Project’s generators cannot independently generate electricity; they rely on shared infrastructure,” according to the complaint.

Emily Doerfler, an attorney for Western Resource Advocates, said allowing the project to circumvent environmental review could pose real consequences for the surrounding residents, because the Corporation Commission’s certificate of environmental review process provides a “one-stop shop” where surrounding communities can voice their concerns and ensure utilities take proper steps to limit the impact on their communities.

She said the certificate of environmental compatibility could even include promises to address potential issues in the future.

“So even if the utility gets the [certificate] and has been approved and is built, if there are ongoing issues such as noise or light pollution or things like that, the community can hold that utility accountable,” she said.

Doerfler cited the SRP Coolidge expansion, where residents in the neighboring Randolph community were able to secure millions of dollars worth of concessions from SRP via the environmental review process, including investment in local infrastructure and community projects.

If utilities can skip that process by splitting large power plants into smaller units, Doerfler said residents would be forced to navigate a confusing mix of local, county and state regulatory processes to voice those same concerns.

“When you take that process away, it puts the onus of protecting your own community on the community members who have busy lives instead of on the utility that's building the major facility,” she said.

A spokesperson for UNS Energy declined to comment on the new litigation.