Corporation Commission Stands Firm on Power Plant’s Environmental Exemption

The Arizona Corporation Commission has pushed back against allegations made by Attorney General Kris Mayes and two environmental organizations regarding its decision to exempt a power plant expansion from environmental review.

In responses filed on October 14, the commission sought the dismissal of three lawsuits, requesting that the Maricopa County Superior Court uphold its ruling allowing Unisource Energy to bypass a Certificate of Environmental Compatibility for the expansion of the Black Mountain Generating Station in Golden Valley.

The legal challenge, initiated by Mayes along with the Sierra Club and Western Resources Advocates, alleges that the commission misinterpreted state laws governing power plant expansions, effectively overturning long-held precedents.

This controversy centers on the commission’s June decision, which reversed an earlier ruling from the Arizona Power Plant and Transmission Line Siting Committee mandating that Unisource obtain the necessary certificate for four new 50-megawatt generators.

According to state law, power plants with a total generation capacity of 100 megawatts or more are required to secure a Certificate of Environmental Compatibility. However, Unisource contended that because each individual generator is below this threshold, the exemption should apply.

The commission’s filings argued that the state statute defines a power plant as “each separate generating unit,” thereby justifying the decision to exempt the Black Mountain expansion, even though the combined output would total 200 megawatts.

In its response, the commission accused Mayes and the environmental groups of misinterpreting the statute and asserted that decisions are made based on the current law rather than precedent. The commission also highlighted that utility companies typically obtain such certificates voluntarily, marking the Unisource case as unique.

Mayes has claimed that the commission’s actions have introduced ambiguity into the law. However, the commission, through its general counsel Tom Van Flein, maintains that it adhered closely to the statute, leaving broader policy interpretations to the legislature.

A spokesperson for the commission declined to comment further on the ongoing litigation. Meanwhile, Autumn Johnson, representing the Arizona Solar Energy Industries Association, expressed skepticism about the commission’s rationale, noting she found the responses “absurd.”

Johnson pointed out that the commission’s assertion of facing this issue for the first time lacks clarity, creating further confusion surrounding the decision.

Johnson also challenged the concept that utility companies sought Certificates of Environmental Compatibility voluntarily, suggesting that such claims had not been made until now.

In addition, Mayes and the environmental groups have accused the commission of violating Arizona administrative code during executive sessions involving named staff parties without proper protocol. The commission denied any violations, asserting that staff presence did not breach communication rules.

Johnson recognized a historical confusion surrounding ex parte communication rules at the commission, suggesting recent changes to its legal team have only compounded the issue.

With no hearings scheduled in any of the three lawsuits, Johnson anticipates that the cases will likely extend past the upcoming election, which will see three commission seats contested. She expects this matter to resonate within the Legislature and influence discussions across various government sectors.