‘Perfect storm’ led to Twin Cities suburban boil water advisory

A computer problem in Golden Valley started the cascade of events that prompted boil water advisories in three west metro communities this weekend and renewed calls for officials to evaluate their aging systems.

In public meetings this week, city managers in Golden Valley and Crystal offered their most detailed accounting yet of the events that left residents in their cities and neighboring New Hope with a decision Sunday and Monday to either boil their water or buy it bottled.

The computer problem caused the cities’ water systems to stop communicating with each other, prompting two water towers to close off as a precaution, while a third water tower in New Hope that would typically serve as a back-up was offline for prescheduled maintenance, the officials said.

“It was kind of a perfect storm,” Crystal City Manager Adam Bell told council members. “Early Sunday morning, we have one water [tower] out, and then this happens.”

The three cities have banded together since 1963 under a Joint Water Commission (JWC) to purchase water from the city of Minneapolis. Bell told council members that each city has been maintaining its own water structures, “but it’s been piecemeal.”

The commission solicited proposals earlier this year from companies that could evaluate the systems, including assessing the condition of some water towers and controls and offering recommendations for improvements. The Crystal City Council on Tuesday agreed to pay roughly $65,000 for the study, with the caveat that the city will be reimbursed by the commission.

What happened this weekend “was a great reminder that this is past due,” Bell said.

In a follow-up email with the Minnesota Star Tribune, Bell said, “The assessment plan will, of course, help inform the JWC about future potential issues, but it would not have prevented the malfunction that led to the incident.”

City officials didn’t say what caused the computer problem that ultimately led to the boil water advisory.

New Hope Mayor John Elder said he asked about the nature of the computer problem and was told there was no evidence of hacking or any other type of “malicious act.”

The New Hope water tower, which is near Medicine Lake and visible from Hwy. 169, would typically kick in as a back-up. But it was off-line for sandblasting and repainting, work that was last done 26 years ago, Elder said.

When staff in several cities noticed water pressure had dropped, teams were called in to help get things back up and running.

“This was a careful, time-sensitive process that required tight coordination between the three cities, and the system must be repressurized gradually to avoid breaking underground water pipes called water mains,” Golden Valley City Manager Noah Schuchman told council members. “Increasing pressure too quickly can cause major damage across the cities.”

Bell said he learned about 8 a.m. Sunday that the cities would be required to issue a precautionary boil water advisory because of the water pressure drops. He said teams worked until about 3 p.m. Sunday to collect water samples, which then take 16 to 18 hours to incubate.

The advisory remained in place until Monday afternoon, when officials announced that no contaminants had been found.

Minnesota has recorded 13 boil advisories this year, all of which were due to a loss of pressure in the water distribution system, according to Kim Larsen, supervisor of the Minnesota Department of Health’s community public water supply unit.

When pressure drops, Larsen said officials test for at least two substances: E. coli, which can cause illness, and total coliforms, which are not harmful themselves but can provide indications that contamination occurred.

Officials in the three cities heard from frustrated residents and business owners who said they wanted to be notified about the water issues earlier and more frequently.

Golden Valley Mayor Roslyn Harmon said during the council meeting that she had heard from some people who had been notified early and some who felt ignored.

“The situation revealed serious gaps in our communication protocols,” Harmon said, “and we must do better.”