Agencies investigate possible discharge from quarry in Santa Ritas

The flow of a white substance 8 miles down a wash, possibly from a limestone quarry in the Santa Rita Mountains, is under investigation by three state and federal agencies.

“It was like a paste and like a sludge and like a really fine silt when it was wet. It had a glossy finish,” said Chris Naylor, who lives in a subdivision the material flowed to after a rainstorm on the weekend of Aug. 17-18. As he drove by the wash, which crosses his property, “It stuck in my wheel wells. It was like somebody had sprayed foam in my wheels.”

Marie Light, of the Pima County Department of Environmental Quality, said she traced the spread of the material from the quarry down the unnamed wash to South Wilmot Road, outside of Sahuarita and the unincorporated Corona de Tucson community.

A state inspector believes the material is non-hazardous calcium carbonate, which is the material mined by the quarry.

But residents living near the wash are nervous because of what they saw happen after similar material came down the same wash in the summer of 2021.

Over the next few months in 2021, 25 pet dogs living in the area got sick with diarrhea, nausea and diminished appetites, Light said residents told her. Eight ultimately died, she was told. Walking down the wash could have made their pets sick, residents said.

While it’s usually harmless to people, it can cause sicknesses to those who “overdose” on it, two medical reports said. The reports describe potential gastrointestinal symptoms similar to those the pet owners say they observed in their animals in 2021.

Mazda Shirazi, medical director for the University of Arizona’s Poison and Drug Information Center, said that before making a detailed assessment of possible impacts of the material that came down the wash, he’d want to know the specifics of what was released.

But generally, as a medical toxicologist and biomedical engineer familiar with mining processes, he would not recommend that people or animals make direct contact with materials such as those that flowed down the wash near the Santa Ritas.

“As long as that’s there, animals lick it and get it on their skin,” he said. “Animals tend to be closer to the ground. You and I have our shoes and socks on and our shirts on.”

Officials of Cimbar Resources Inc.,, the quarry’s current operator, and Imerys Carbonates USA Inc., which operated the quarry from the late 1990s before selling its interest to Cimbar in 2022, said they have no knowledge of any discharges from the quarry either in August or any year before that.

After the mid-August incident, a state inspector visited the site for the Arizona Department of Environmental Quality

“Based on the inspector’s observations, including a visit near the calcium carbonate mine, and the material’s characteristics, we believe the white residue is calcium carbonate, a common and naturally occurring mineral that is abundant in the area,” ADEQ spokeswoman Alma Suarez told the Star.

Companies say no discharges occurred

Reached by phone at the quarry for comment, a man who identified himself as its plant manager said he doesn’t believe anything escaped from the quarry.

The Santa Ritas mine, located on 53 acres of Bureau of Land Management property at the base of the mountains, produces ground calcium carbonate. It’s sold throughout Arizona and “serves various markets, including building and infrastructure (cement and chips), joint compounds, and agriculture (animal feed),” the company said in a statement.

CIMBAR operates the facility in full compliance with ADEQ regulations and hasn’t received any notices of violation of its operating permits, the company’s statement said.

“Committed to maintaining these standards, CIMBAR continuously monitors all discharges as required by the State of Arizona. The manufacturing process at the Santa Rita mine is entirely chemical-free, ensuring no chemical hazards are introduced to our products or the environment,” the statement said.

“All our materials are caught before it leaves our property,” said the current manager, who identified himself on the phone only as Ed. Later, an email to the Star that included a company statement was sent by Ed Zedaker, who identified himself as the quarry plant manager.

But, “if anything left my property, there’s nothing dangerous about my substance. It’s calcium carbonate. There’s no chemicals or anything,” the manager told the Star.

“We produce this product for animal feed. There’s no way it will make animals sick,” he said. “We have wildlife living up in this quarry. We got pigs. We got deer. We got mountain lions. We got coatimundi.”

The previous owner, Imerys, said it had no records of any discharges from the quarry site, not only in 2021 but since it began operating the quarry in the late 1990s.

“We have conducted a thorough review of our legacy data of the Sahuarita site. Imerys has no record nor awareness of any incident related to contaminated water at the Sahuarita operations in 2021. Furthermore, Imerys has no similar findings at any time the site was owned and operated by Imerys,” Ginny Dunn, the company’s communications director, told the Star.

Imerys filed eight mandatory discharge monitoring reports with ADEQ from 2020 through 2022. None showed any discharges.

“Any event would have been something we would immediately have noted,” Dunn said. “We have no record of this, officially or unofficially.”

ADEQ officials also checked their records several times, and didn’t find any reports of complaints about discharges from the quarry in 2021, spokeswoman Suarez said.

“The recent complaint is the only one the agency has received,” said Suarez, referring to the incident of August.

Natural calcium carbonate embedded in limestone rock outside the quarry could also be a potential source of discharged material into the unnamed wash where the recent discharge occurred and where a 2021 discharge may have occurred, said an official with the Arizona Geological Survey.

A federal map of that area shows that limestones are present at least 2.5 miles north of the quarry, about 5 miles south of the quarry and about 2 miles west and west-northwest of the quarry, said Carson Richardson, a senior research scientist for the survey..

“There are at least two other areas where limestones are present that could feed detritus into the same wash,” said Richardson, who heads the survey’s bedrock geology and mineral resources group. There’s a lot of limestone up there and (it) could be flowing down different contributing drainages to the same wash.”

Investigations underway

The BLM “plans to investigate and will take appropriate action based on the facts and within our authorities,” June Lowery, an agency spokeswoman, told the Star, referring to the August incident.

Tailings, dumps, deleterious materials or substances, and other waste produced by operations on BLM lands should be contained and disposed of per the approved mining plan of operation, Lowery said. BLM rules require that all such materials “be disposed of so as to prevent unnecessary or undue degradation and in accordance with applicable federal and state laws.”

The Arizona Attorney General’s Office is also investigating the August incident, although office spokesman Richie Taylor said it’s too soon to determine if it’s looking into the possibility any law was violated by possible discharge from the quarry.

“We’re looking into the situation to determine the facts of what might have happened,” Taylor said.

Also, “out of an abundance of caution to be protective of public health and the environment,” ADEQ has since visited the quarry again to take samples of the material for testing, to confirm it is calcium carbonate, Suarez said. Test results will probably be ready in the next week or two, she said.

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The agency recommends that private well owners in the area test their wells for possible contaminants, following guidance provided by the Arizona Department of Health Services, Suarez said.

The ADEQ also has enforcement authority over violators of state and federal anti-pollution laws. But it says it lacks authority to carry out enforcement action against the quarry because the washes the site feeds with rainwater aren’t protected under the federal Clean Water Act.

One reason for that could be that a 2023 U.S. Supreme Court ruling weakened and possibly eliminated federal agencies’ legal ability to regulate pollution of washes like this one that only carry water after storms.

The substance in “hard” water

Calcium carbonate is also found naturally in chalk, eggshells and seashells and is the major component in “hard” water, Suarez said. Calcium carbonate causes scale buildup on pipes and appliances, but typically isn’t harmful to animals or humans, she said.

It’s not classified as a hazardous substance or a hazardous waste under federal rules, she said.

It’s a common dietary supplement, typically recommended for people known to have calcium deficiencies. It’s also used as an antacid and to treat a wide variety of internal organ ailments, including some kinds of ulcers, kidney disease, gastrointestinal damage and pancreatic insufficiency, says a 2023 report from the National Library of Medicine.

But people can suffer “moderate to severe” side effects “if large doses are taken for an extended time or abused,” the same report said.

Calcium supplements, which are beneficial for many people including those with osteoporosis, may increase the incidence of constipation, severe diarrhea, and abdominal pain, said another National Library of Medicine report. It added that calcium carbonate is “more often associated with gastrointestinal side effects, including constipation, flatulence, and bloating.”

County’s report

The first person to notify authorities about the white substance was Chris Naylor, who lives about 5 miles north of the quarry in a 320-home subdivision called Entrada. He called a U.S. Environmental Protection Agency hotline.

Next he called the Pima County Regional Flood Control Department, and “they sent me to ADEQ. After that, it seems that every agency of government has contacted me one way or another” about this, he said.

“The wash is now compromised as far as this watershed goes,” he said. “Now, you stand on the wash, it’s like standing on concrete. It’s solidified. It runs more now (when it rains) because there’s no sand to slow it down.”

When cars go down the road, they kick up the dust, making it airborne, he said. “People jog down that road and walk animals down that road and through the wash,” he said.

Pima County’s Light traveled to the wash the same day and started tracking the white material from where it stopped occurring near Wilmot Road upstream towards the wash’s source.

She responded quickly to Naylor’s complaint because he had described the event of three years ago when the pet dogs and cats started getting sick after similar material traveled down the wash, she said.

It took Light three days, until Aug. 21, to trace the spilled material upstream to the quarry site, where she found the same material at its entrance that she had seen in the wash downstream, she said.

At the entrance to the quarry, “I saw a small wash on the north side of the entrance with extensive amounts of the white substance,” Light wrote in a report about her investigation. “About 300 feet to the west of the entrance, I saw a channel eroding the side of the road with the white substance at the bottom of the channel.”

She also found the thickest buildup of the calcium-based material — about three-quarters of an inch — existed at a spot on the wash near Naylor’s house.

“I’ve never seen a white wash in Arizona. This is totally new,” said Light, a hydrologist for the county environmental agency for 14 years. “Everything should be a deep tan color, at least.”

Sick animal reports

Back in August 2021, Lyn Sorce, an Entrada resident like Naylor, said she and some friends started talking about reports they’d heard of sick dogs about a month after the white material started flowing down the same wash early that summer.

Sorce’s own dog, a year-old purebred Yorkshire terrier, started to seem lethargic that summer, she said. Then, the terrier had diarrhea and vomiting. Although a veterinarian prescribed antibiotics and anti-parasitic medication for the dog, “they did no good,” and the dog died that November, Sorce said.

That summer, she tracked reports of up to 30 sick dogs on posts on a Facebook group run by the Entrada Property Owners Association.

Eventually, she tracked the dog owners’ homes on Google Maps, and discovered that all lived downstream form the quarry near the wash where the white material had flowed, she said.

She said she called “everything from federal officials to county officials to get our land, water and our soil looked into. Nobody believed me back then. They thought I was crazy. I gave up. It’s actually kind of mind blowing that people are taking it seriously now.”

Pima County’s Light said that while she doesn’t know if the white material in the wash caused the neighbors’ pets to get sick and die, she said she thinks it’s a possibility. The pets could have been exposed to the material by inhaling or ingesting it accidentally, she said..

But because the aquifer serving people who live in that area through private wells is at least 100 feet deep, Light said it’s unlikely the material that came down the wash could have been dissolved by stormwater and then seeped that far into the aquifer in a few months.

Clean Water Act implications

For any possible enforcement action, Pima County DEQ referred the incident to the Arizona DEQ. In part, that was because the quarry lies on federal land and the county lacks the legal authority to take enforcement action on such a complaint involving federal land, Light wrote in her report.

But ADEQ lacks regulatory authority to take enforcement action in this case because the white substance that appeared to come from the quarry didn’t reach any rivers or streams that are legally protected by the federal Clean Water Act, said Suarez, the ADEQ spokeswoman. The agency also determined that calcium carbonate isn’t regulated under ADEQ’s solid or hazardous waste program, she said.

Before May 2023, the wash that carried the calcium carbonate could theoretically have qualified for Clean Water Act regulation if federal agencies determined it had a “significant nexus” with a navigable river such as the Santa Cruz River to the west. But a U.S. Supreme Court ruling that month threw out the “significant nexus” test and applied much stricter standards for determining Clean Water Act jurisdiction over rivers, streams and washes.

To many legal experts, the decision stripped protection from ephemeral washes like this one that carry water only during storms.

But ADEQ has not determined the regulatory status of these drainages under the current and past definitions of federally protected rivers and streams, commonly called Waters of the U.S. by federal officials, Suarez said.

She said, in effect, that current, federal Waters of the U.S. definitions don’t clearly say whether they include ephemeral streams such as this one.

“ADEQ continues to engage with the and EPA to determine how to apply the current definition of Waters of the U.S.,” Suarez said.

The site’s previous owner, Imerys Carbonates USA Inc., had a Clean Water Act permit from ADEQ. But it terminated the permit in June 2023 after selling the quarry to Cimbar, it told ADEQ at the time. The agency is now working with Cimbar to see if such a permit is needed, Suarez said.