Portland and two other Maine cities were among 33 nationwide that for several years employed methods for testing drinking water that could indicate lead levels are lower than they actually are, according to an investigation by The Guardian newspaper.

But officials from the three public water systems – Portland, Bangor and Lewiston – said Thursday that they all believe they were complying with the Environmental Protection Agency’s guidelines at the time. All three changed their testing practices this year when the EPA issued revised recommendations. The Guardian report said those recommendations had been issued years ago, but officials from the Maine water districts said they believe they were brand new this year.

The state says the EPA had never issued recommendations before this year and that even those are guidelines, not regulatory requirements.

“The EPA did not issue any guidance on this practice until February 2016, so it is not accurate to say systems were out of compliance,” said John Martins, spokesman for the Maine Drinking Water Program, part of the Maine Center for Disease Control and Prevention’s Division of Environmental Health.

The EPA’s New England Regional Office did not respond to questions Thursday about when it first changed its recommendations for residential water testing.

The water district officials in Maine said protecting the public health is paramount to their work and that they never took steps intended to skew test results lower.

“(The Guardian report) did offend people here and probably in the industry,” said Michelle Clements, spokeswoman from the Portland Water District.

After the recent lead contamination crisis in Flint, Michigan, the Guardian asked 81 municipalities east of the Mississippi River about their methods of testing drinking water for lead.

Its investigation, published online Thursday in the British news organization’s U.S. edition, found that over the past decade, 33 of those cities in 17 states asked people taking samples from their homes to remove metal filters called aerators from the end of their faucets, “pre-flush” their faucets by running the water for a few minutes or seconds before taking a sample, or to run the water slowly when taking the sample – all of which can reduce the amount of lead showing up in the sample. Similar practices were used in Flint.

The Guardian reported that the Lewiston Water Division had asked residents to take all three measures, the Portland Water District had instructed residents to pre-flush and run the water slowly, and the Bangor Water Division had asked residents to pre-flush.

SOME ACCUSATIONS ‘ALARMIST’

The report called the practices “water testing ‘cheats’ that potentially conceal dangerous levels of lead.”

“Some of the accusations in the article are very alarmist,” Clements said.

Instructions that the Portland Water District handed out in 2008 – obtained by The Guardian and provided to the Portland Press Herald – direct residents, before taking a sample in the morning, to “run the cold water tap for ten seconds before shutting it off for the last time at night to flush out any hot water that may be remaining in the faucet.” The EPA began recommending against that practice during the same year, according to The Guardian story.

“We have no record of that at all,” Clements said of the 2008 EPA recommendation.

The Portland instructions also said to “gently open the cold water tap filling the bottle,” which Clements said was language that had been suggested by the EPA.

When the EPA clarified this year that it now recommends against those practices, the Portland Water District changed its instructions for taking samples accordingly, Clements said.

Dina Page, water quality manager for the Bangor Water District, also said she was unaware of the recommendation against pre-flushing, a practice that she said was used to make sure all the samples sat for the same amount of time and didn’t come from a faucet that hadn’t been turned on in days, which would skew the results upward.

“It’s unfortunate when the science of this gets lost,” she said.

Lead levels in Bangor exceeded standards from 2010 to 2012 and again in 2013, even though residents were being asked to pre-flush, Page said. She said that should prove the district wasn’t trying to “game the system,” she said.

Kevin Gagne, superintendent of the Lewiston Water and Sewer Division, said he doesn’t believe Lewiston asked residents to run water slowly, as The Guardian reported, and that he didn’t know about EPA recommendations made before this year against pre-flushing or removing aerators. The city’s instructions no longer recommend doing either.

The most recent EPA guidelines say the agency issued a memo in 2006 recommending that homeowners regularly clean their aerators but not that they should be instructed to do so before taking a sample for testing.

Like Page, Gagne said Lewiston’s practices were meant to ensure accuracy.

“You don’t just want to know what’s in the fixture or in the filter that’s in the fixture,” he said about why they asked residents to remove aerators.

“The Guardian paints it like a violation of a standard, but it was really an EPA recommendation that was never well published, in my opinion,” Gagne said.