The following Tuesday, the city’s building authority received notification that further raw water samples taken from the same four wells on Monday showed no evidence of the bacteria.

These water samples were sent to another laboratory for testing because the city government believed the positive results were the result of a laboratory error. The results of the follow-up tests seemed to confirm this assumption.

“It has not yet been definitively determined” whether it was a lab error, Mark Hollowell, director of the Department of Buildings, said Friday. “The Department of Buildings contacted us today and found no errors in the lab procedures. They also inspected our sites today and found nothing that visibly contributed to the lab result. They determined it was a surprising and unique result.”

Local authorities assumed the initial test results were a laboratory error because the results were the same at wells four miles apart and such bacteria had never been found in tests in the city before.

“We took five separate samples from each well on the day the problem was reported and all 20 well tests found zero bacteria,” Hollowell said.

The lab that conducted the first round of testing, RI Analytical, has been used by the city for years and there has never been a problem, he said.

“We use a number of laboratories and put our services out to tender annually,” Hollowell said.

Local authorities discussed ending their contract with RI Analytical, but this occurred before the DEP investigation.

If the lab had been accused of negligence, city officials would have had little claim for compensation for the costs incurred by the city, residents and businesses — several of which had to close.

“It was the DEP’s decision to boil the water,” Hollowell said. “I’m sure the legal fees would be more than it’s worth.”

RI Analytical could not be reached for comment.

The DPW has city water tested weekly and monthly as per state requirements. This particular test of raw water bacteria samples is done monthly, Hollowell added.

The city has nine wells, five of which are treated at the Whiting plant, as well as a well in Plainville, two wells at the McKeon plant on Kelley Boulevard, the Adamsdale well and the Hillman well on Hunts Bridge Avenue.

The wells in which the bacteria test was positive were located at the Whiting and McKeon drilling sites.

DPW employees and other city officials have faced severe criticism from the public and businesses because of the water emergency.

“People were obviously pretty frustrated. A lot of us felt our staff was doing a bad job because we’ve been given two boil water orders in two years. But they’re doing a great job,” Hollowell said. “People don’t understand that this is raw groundwater before we treat it.”

In September 2022, a boil water advisory was issued after tests showed the presence of E. coli bacteria in a city well. The advisory was lifted the next day when further tests came back negative after two wells were taken offline.

This order was also implemented in Plainville, but this time the connection to the water supply in North Attleboro was shut off.

The reason for the boil water order is because the DEP implemented a relatively new groundwater rule that requires water to be in contact with chlorine for a long time before it can be released into the distribution system, Hollowell said.

After the last boil water order, the city hired an engineer to work at the Whiting plant.

“We just finished the design for this and will be putting it out to bid next month,” Hollowell said of the project. “Once that is completed, a boil order on the Whiting Well will no longer be required in the event of any attacks on raw water.”

“It’s pretty complicated, so I understand why residents feel like the department is making mistakes and not following the DEP’s guidelines, which are just being cautious,” Hollowell said.

Residents can get free water 24 hours a day from the dispenser at the DPW’s Whiting Street headquarters, and due to the recommendation to boil water, this meeting place was very popular last week.

The kiosk stopped working on Thursday and was repaired by a technician.

“The filters may have needed to be replaced after such frequent use,” Hollowell said.

The kiosk uses two filters that remove “pretty much everything” from the water, including chlorine, he added.

“Residents were understandably concerned and frustrated by the notice,” said North Attleboro City Council member Dan Donovan. “The wording of the notice and the boil water order itself were prescriptive. The city must comply under state law.”

“It is important for residents to know that at no time have there been any positive test results from water samples treated at the treatment plant,” Donovan said.

Residents and businesses have been advised that all water used for cooking, drinking, brushing teeth, washing dishes or preparing food should be boiled.

There was a rush on water bottles in many stores.

Local resident Laura Wagner took the situation calmly.

“It was extra work, but I boiled water and it was OK,” Wagner said.

She pointed out that a local market had to get rid of produce it had sprayed with water, that Cumberland Farms was no longer making coffee, and that Dunkin’ was closed.

“I think it was even harder for local businesses than for private households,” Wagner said.

Vilorio’s Italian Bistro was not affected because owner Santos Vilorio pointed out that the downtown restaurant is closed on Mondays. He wanted to drink bottled water on Tuesday night, but then the boil water advisory was lifted.

Residents were also advised to dispose of items made with tap water and flush out hot water tanks.

Enterococci bacteria live in the intestinal tract of warm-blooded animals, including humans, and indicate possible fecal contamination of streams and rivers. Enterococci are generally not considered harmful to humans, but their presence in the environment can indicate that other pathogens, such as viruses, bacteria and protozoa, may also be present.