The Environmental Protection Agency says the Army Corps of Engineers violated a key federal policy and kept it in the dark in advance of a recent decision to remove Clean Water Act permitting authority over the proposed Rosemont Mine.

The Corps’ March 24 decision to waive its jurisdiction over the mine site will free mining company Hudbay Minerals Inc. from potential future requirements on an extensive and protracted permitting process that had lasted more than a decade. The Corps said new federal rules covering regulation of development along washes no longer require Hudbay to get a Clean Water Act permit.

In an Aprll 8 letter to the Corps, a top official in EPA’s regional office, Tomas Torres, contended the Corps violated a federal policy that would have involved much more formal and detailed consultation with EPA before the decision.

The Corps’ decision came after lower-level EPA officials told the agency in informal memos that the mine site had stream flow characteristics of the kind for which federal rules still allow regulation.

The Corps disagreed, and said in its decision that the issues involving its authority over the washes didn’t merit such formal consultation with EPA. The Corps said it did "engage in informal coordination" with EPA.

A longtime mine opponent, Pima County Administrator Chuck Huckelberry, said failure to adequately consult with the nation’s top environmental agency could have led to an erroneous and less informed decision.

Huckelberry said the Corps' failure to adequately consult with EPA is a problem of due process. “Without that input the decision is less informed. It means that EPA’s perspective isn’t considered. Input from EPA might have altered the decision,” he said.

“These are complex decisions requiring consideration by multiple experts. Anytime you leave one group out of the decision-making process you potentially may make a decision in error,” Huckelberry said.

Late Friday, Corps spokeswoman Dena O’Dell said the agency is aware of the EPA letter, “and we are considering its content and appropriate response.”

Hudbay Minerals Inc., which proposes to build the open-pit copper mine in the Santa Rita Mountains southeast of Tucson, didn’t respond to a request from the Star for comment on EPA’s letter.

That letter was one of several internal federal documents the Star obtained last week that raised procedural and substantive questions about the Corps’ decision to remove Clean Water Act permitting requirements for Rosemont.

Most of the washes don’t have year-round water

The proposed mine still faces extensive oversight under a separate approval it received from the U.S. Forest Service. That approval was overturned by a federal judge, in a decision now under appeal by Hudbay and the U.S. government to the 9th Circuit Court of Appeals.

In its latest Rosemont decision, the Corps concluded the mine no longer needs a Clean Water Act permit because most washes traversing and leaving the mine site are ephemeral, meaning they carry water only after storms.

Development along such washes is no longer regulated under the Clean Water Act due to changes in federal regulations made in the final year of the Trump administration, which removed federal authority over them. Until then, the Corps’ and EPA’s rules had regulated and protected ephemeral washes in many cases.

The Corps’ recent decision did identify three washes on the mine site that run intermittently or perennially, which under the new rules can still be regulated. But the Corps concluded that those washes don’t merit protection because they don’t contribute water flows in a typical year to a navigable stream — in this case, the Santa Cruz River, about 56 miles downstream of the Rosemont site.

Field observations conducted by a Hudbay Minerals consultant during the monsoon season, the wettest time of the year, show that these streams’ wetted areas last no more than about 50 to 350 feet downstream of the "source," said the Corps’ decision, written by Mike Langley, a senior project officer in Phoenix. Langley didn't elaborate on what that source is.

"This indicates the downstream flows are only locally relevant within a very small portion of the watershed and would have no meaningful connection" to the Santa Cruz, Langley wrote.

Different stance taken months earlier

But a document obtained by the Star shows that Langley had taken a different stance barely three months earlier in an email to an EPA official.

Langley wrote to EPA’s Rob Leidy on Dec. 12, 2020 that “if my recommendations hold,” he expected the Corps would exercise jurisdiction over part of a major wash on the mine site, Barrel Canyon, and two or three “wet stream segments.” He didn’t elaborate.

The Corps’ decision didn’t mention that email to EPA’s Leidy or explain why that recommendation didn’t hold up. The Corps didn’t respond to a question last week from the Star about that email.

In a Nov. 30, 2020, memo to Langley, Leidy wrote that he found in reviewing stream gauge data that “surface waters” at the mine site connected with the Santa Cruz in “typical year conditions” in four different years between 2010 and 2018. Leidy is an EPA ecologist and enforcement officer in San Francisco.

“As you know, one only needs to show a connection under typical year conditions once,” wrote Leidy, in an apparent reference to the conditions needed for a water course to qualify for regulation under the new rules.

Langley’s decision provided a detailed analysis of flaws he found in arguments raised by EPA and Pima County officials favoring regulation of washes on the mine site. In an apparent reference to Leidy's point on streamflow in a typical year, he said an assessment of such flows is only necessary for non-ephemeral streams. His response and Leidy's memo didn't spell out whether the "surface waters" Leidy discussed were ephemeral or intermittent.

Unusual discord

This lack of harmony between EPA and the Corps on Rosemont is unusual because the two agencies have worked closely together on the mine issue since the early 2010s, and on federal Clean Water Act regulatory issues in general.

In 2016, when the Corps’ Los Angeles District recommended against permitting the mine, EPA was notified of the decision in advance. It already had provided extensive comments opposing the permit.

The same notice occurred in 2019, when a higher-level Corps official in San Francisco overruled its L.A. District and granted the Clean Water Act permit. In that case, EPA chose not to contest the decision even though EPA legally has a veto power over Corps permits and had continued writing memos opposing the mine.

That permit is still being challenged in court by mine opponents. If it were to be overturned, Hudbay could have been stopped from building the mine if the Corps had maintained jurisdiction.

And, without federal authority over the washes on the mine site, Hudbay would be free of its obligations to buy land in other areas to compensate for damages done to the washes. Hudbay has bought a considerable amount of other land, including 1,200 acres near Sonoita Creek in Santa Cruz County south of the mine site.

In the April 8 EPA letter to the Corps, EPA official Torres noted that the two agencies worked “in tandem” in preparing the new Trump administration regulation governing which washes deserve regulation, otherwise known as the Navigable Waters Protection Rule.

Plus, the agencies worked “extensively” together to issue an August 2020 memo of guidelines aimed at insuring consistent implementation of the new Navigable Waters Rule, wrote Torres, director of EPA’s San Francisco regional office’s water division.

In its Rosemont decision this year, the Corps not only failed to follow that memo, “but ignored EPA’s explicit request in December 2020 for notification prior to the issuance of the final jurisdictional determination,” Torres wrote.

The coordination policy requires, in certain cases, that the Corps provide a draft of its decision to EPA 14 days before finalizing and publishing it, to give EPA time to review and formally comment on it.

“This is particularly troubling given our long-standing federal partnership and engagement on Clean Water Act permitting matters for more than two decades, and the many years EPA has engaged with the (Corps) on the Rosemont Copper Mine,” Torres wrote to Col. Julie Balten, commander and district engineer of the Corps’ L.A. District.

Corps says consultation standard wasn’t met

In the Corps’ March 24 decision, however, the Corps said it’s not required to coordinate with EPA on the Rosemont project because the issues at stake don’t meet the standard set for justifying the coordination effort.

The standard is highly technical. It requires a showing, for instance, that a Corps decision to decline jurisdiction over a specific wash was based solely on a finding that such a wash doesn’t convey streamflows to a downstream river or wash that is federally regulated.

“While EPA strongly disagrees with this determination, it is clear that there is a breakdown in how our staff are implementing and interpreting the coordination memo which does not serve the interests of either of our agencies or the public,” Torres wrote.

Also, the Corps’ Langley wrote EPA official Leidy a memo on Nov. 10, 2020, promising to let EPA know in advance of whatever decision it made on its authority over the mine.


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Contact Tony Davis at 520-349-0350 or tdavis@tucson.com. Follow Davis on Twitter@tonydavis987.