‘Well, can we just shut it off?’: Anchorage water utility official recounts Mayor Bronson’s decision to temporarily shut off fluoride in city’s water

Under questioning by members of the city Assembly, Anchorage Water and Wastewater Utility manager Mark Corsentino gave more details about what happened at the the Eklutna Water Treatment Plant in October when Mayor Dave Bronson decided to briefly shut off fluoridation of the city’s water supply.

During a work session on Friday, Corsentino’s account was largely in line with previous statements from the mayor’s office, and he said he did not think the mayor violated city code. However, some points conflicted with past statements from Bronson officials. The mayor’s office, for example, has said Corsentino asked the mayor to turn off the fluoride. During the Assembly’s Friday work session, Corsentino said he did not.

Corsentino also called Bronson’s order “surprising.”

“I wasn’t in a position where I was gonna argue with him and say, ‘No, don’t do this.’ It was quick. It was surprising. Don’t get me wrong, but the logic in my mind, right, wrong or different, I deemed that to not be a threat. And we were OK with it,” Corsentino said. “So we said, ‘OK.’ And we recognized that he was going to take this up right away or change his mind.”

Assembly members have had lingering, unanswered questions about the incident since it was first made public by the Alaska Landmine last month in an article that cited anonymous sources.

Several members have questioned whether the mayor violated city code by shutting off the fluoride, which the mayor’s office disputes. Assembly leadership launched an inquiry after the incident became public, sending rounds of questions to the mayor’s office and to Corsentino, and also requesting public records from the administration.

The mayor’s office categorically denied at least twice that the incident occurred, initially telling Landmine it “did not happen” and again telling Alaska Public Media that the allegation was false. But within days of denying it, the mayor’s office confirmed it did occur, and said Bronson ordered the fluoride to be shut off because of health and safety concerns from AWWU staff.


During the questioning on Friday, Assembly Vice Chair Chris Constant and Corsentino disagreed over whether the mayor broke city code, though both said that reliable interpretation of the code should be done by lawyers.

[Anchorage’s first chief equity officer settles lawsuit against Bronson administration]

City code stipulates Anchorage’s water supply must be fluoridated. The code states that the manager of the utility is “authorized and directed to continue supplementing the fluoride content of the water supply.”

Corsentino said that because fluoride stays in the system even when the fluoridation system is paused, he believes the mayor did not break city code. Corsentino said AWWU often shuts down the system for maintenance.

Constant said this instance was different because there was no maintenance reason to shut off the fluoride.

“I have a disagreement that shutting off the water for the intent that it was shut off was done within the code — and it certainly wasn’t a violation for long — but that’s a conversation we can take up later,” Constant said.

‘We did it immediately upon the ask’

Corsentino said the tour included Bronson Chief of Staff Sami Graham, Deputy Municipal Manager Kolby Hickel, and Dan Zipay, director of the city’s Solid Waste Services, along with AWWU’s administrative director who oversees safety and public outreach, its public outreach director, and the plant’s superintendent and foreman.

The tour began with Corsentino giving the mayor an overview of the treatment processes at the plant, including fluoridation, which is the last treatment process, he said.

“He asked me to tell him more about fluoridation,” Corsentino said. “... It was part of the conversation.”

They discussed how the issue had resurfaced several times locally, with a “growing” number of people against water fluoridation, Corsentino said. He told Bronson that AWWU needed to know “sooner than later” if there would be a policy change at the local level, because it must soon upgrade the system.

“We’re getting ready to spend a million-plus dollars on an upgrade to that fluoride system. If we do the upgrade and then it’s turned off, that would be concerning to me,” Corsentino said.

[No-shows by Bronson officials at meetings leads to dispute between Assembly members and municipal manager]

“He took everything he heard in context and said, ‘Well, can we just shut it off?’ ” Corsentino said.

Corsentino said the plant foreman physically shut off the fluoride system after Bronson asked if they could shut it off and Corsentino concurred.

“We did it immediately upon the ask,” he said.

Bronson had said he would immediately address the issue with the Assembly and the public, Corsentino said.

He told the mayor that fluoridation can be paused without breaking city code because it stays in the system for “days ... if not weeks later,” Corsentino said.


“In essence, it was a pause. We let him know that there is time if you want to reverse that decision. There would be time to still satisfy code requirements because we regularly take it down for periods of time for maintenance,” he said.

Fluoridation at the water plant in Girdwood has been shut down for months due to issues with the system, Corsentino said.

After about six hours, Municipal Manager Amy Demboski and the mayor told Corsentino to turn the fluoride back on, he said.

In a previous statement, the mayor’s office said Bronson directed it be turned back on after he “determined Municipal Code requires the fluoridation of Anchorage’s water supply.”

On Friday, in response to a question from Constant about why the mayor changed his mind, Corsentino said Bronson wanted to take a “more deliberative approach.”

“It was done in haste for good intentions. But that can bite you and he would rather take a different approach to make sure it’s done more thoughtfully. That’d be my interpretation,” Corsentino said.

Conflicting accounts remain

Constant also asked Corsentino about an email sent by an AWWU employee to other employees notifying them that the mayor had ordered fluoride be shut off, and asked Corsentino why that email made no mention of worker concerns.

“I think the reason why it was sent out was so the next group of operators would know that fluoride was shut down. It was probably done in a quick haste, just, ‘Hey, it was shut down. We had a discussion,’ ” Corsentino said. “It wasn’t intended to be comprehensive, to elaborate every reason why it was shut down.”


Constant also asked about differing statements made by Corsentino and Hickel about conversations between the two of them before the mayor’s Oct. 1 tour.

During a previous Assembly meeting, Hickel told members that when she toured the facility in August, Corsentino and others had “made it very clear to me that this chemical, even with the proper PPE on, it burned their eyes, it burned their throats, irritated their skin.”

She had said Corsentino had brought up the issue several times between August and the Oct. 1 tour, “wanting to get in front of the mayor to discuss possibly not using fluoride.”

On Friday, Corsentino said it was not him who brought up the health and safety issues, but the AWWU employees operating the fluoride system.

When Constant asked Corsentino whether he had asked Hickel and the mayor to remove fluoride from the water systems, Corsentino replied, “No I did not. Not that I remember.”

“Our memories are different then, because I don’t remember that conversation,” Corsentino said.

Hickel on Friday said she’d spoken with Corsentino several times between her August tour and the mayor’s tour in October.

“He did say multiple times he wanted to talk about fluoride and the health issues,” Hickel said. “He didn’t directly at that time, prior to Oct. 1, ask me to ask the mayor to turn off the fluoride. However, my recollection of the conversation Oct. 1, the mayor said, ‘What is the ask here?’ And the overwhelming response was to turn it off.”

After the meeting, Constant said he was left with more questions following Hickel and Corsentino’s diverging statements.

Member Jamie Allard, an ally to Bronson, said she did not understand why time was being wasted on the work session.

“The bottom line is, the mayor didn’t violate code,” Allard said.

Memo released on worker concerns

In a letter to Assembly members sent Friday, Demboski released to the Assembly a December memo Corsentino sent the mayor’s office about the issue.


The memo says the general sentiment among Eklutna plant employees is that they feel safe using all the proper personal protective equipment for “loading fluoride.”

“But, if given a choice, they would rather not handle it. It has been expressed amongst operators that after loading fluoride with the proper PPE you may experience a chalky taste in your mouth or eye and nose irritation on occasion while cleaning up post loading process,” Corsentino wrote in the memo.

The memo also discusses steps AWWU has taken over the years to address concerns of workers, such as using more granular fluoridation products rather than powdery ones.

The health and safety concerns that workers have experienced are not reportable to the federal Occupational Safety and Health Administration but have long been issues, Corsentino said.

AWWU has not taken any new steps to address the problem since the mayor briefly turned off the fluoride, he said.

“It’s a known issue. It’s an issue that’s addressed to the best of anyone’s ability, but still it resides,” Corsentino said. “It’d be similar to going your attic or playing around with the batt insulation and getting itchy and irritated.”


Fluoride in drinking water is strongly supported by public health experts. It is effective, safe and reduces and controls tooth decay and promotes oral health, according to the federal Centers for Disease Control and Prevention. The safety and benefits of fluoride have been well-documented and reviewed comprehensively, the CDC says.

Corsentino said the utility does not take a stance on fluoridation because it is a public health issue and an Assembly decision.

Emily Goodykoontz

Emily Goodykoontz is a reporter covering Anchorage local government and general assignments. She previously covered breaking news at The Oregonian in Portland before joining ADN in 2020. Contact her at