Listen to today's Environment Report

The Environmental Protection Agency says it’s conducting a full review of what happened in Flint.

For more than a year, state officials assured city residents their water was safe. Those assurances turned out to be wrong.

And it wasn’t until some residents got outside experts involved -- who not only found elevated lead levels in the drinking water, but that blood lead levels were also rising in Flint kids – that the state admitted there was a problem.

One of the more troubling charges made against the state is that the Michigan Department of Environmental Quality knowingly dropped lead test samples to avoid exceeding a federal drinking water standard.

Curt Guyette with the ACLU of Michigan wrote about this in September:

An investigation by the ACLU of Michigan -- conducted in conjunction with the study of Flint's water by researchers at Virginia Tech and the citizen group Coalition for Clean Water -- has found that the city, operating under the oversight of the Michigan Department of Environmental Quality, took multiple actions that skewed the outcome of its tests to produce favorable results.

State officials maintain they followed the testing rules for lead under the Safe Drinking Water Act.

But others say that’s just not true.

Marc Edwards is an expert on water treatment at Virginia Tech University. He said the first and most important step did not occur in Flint.

The city is supposed to test homes known to either be serviced by lead service lines, or that have lead pipes or pipes with lead solder in them.

Large water systems are supposed to test the "worst-case-scenario" homes to see if they have a problem.

That’s the point of the federally-mandated Lead and Copper Rule. Large water systems are supposed to test the “worst-case-scenario” homes to see if they have a problem.

“They did not do that, and that is the primary reason that they missed the worst of the lead problem,” says Edwards.

Edwards lays the blame squarely on the Michigan Department of Environmental Quality – not the city of Flint.

It was a state-appointed emergency manager who made the decision to switch the city’s source of drinking water to save money.

And it was the state’s responsibility to make sure that Flint was managing that switch correctly.

An altered report

“Even though they didn’t sample the highest risk homes in the samples collected by the city, they were still over the action level. So MDEQ, and I’ve never seen this in 25 years, took the initial report that the city gave and altered it,” says Edwards.

Edwards and the ACLU of Michigan obtained internal documents that showed the city originally submitted 71 drinking water samples to the state in July.

We did the math on those samples using the federal lead and copper rule. This original sample pool of 71 put the city over the federally mandated action level of 15 parts per billion of lead.

The city would have had to alert people that there was a lead problem, and they would have had to implement a corrosion control plan to keep the water from corroding the insides of pipes – a plan that was surprisingly absent in Flint. And they may have been required to start replacing lead service lines in the city.

This is all an expensive proposition in a city that made the switch to save money.

But that never happened.

State officials came back and told the city to drop two samples.

Dropping those two samples put the city below the action level for lead. If the state had just dropped one high sample, Flint still would have been over the federal action level.

But dropping two samples put them below the action level.

To see exactly how this math works, check out this post.

The samples in question

Mike Glasgow is with the city of Flint. He’s the guy in charge of collecting the water samples.

Glasgow remembers including samples taken at one home that showed extremely high lead levels. A sample of Lee Anne Walters' home turned up a result of 104 parts per billion – almost seven times the federally mandated limit.

"I don't know that I can give you a good enough answer to tell you why they decided to remove it from the report."

“They instructed me to take it off the report,” says Glasgow. “I know she had taken some other samples and they had all the results too. I don’t know that I can give you a good enough answer to tell you why they decided to remove it from the report.”

The state denies any wrongdoing.

Dan Wyant is the director of the Michigan Department of Environmental Quality.

“What you’re suggesting is somehow that we dropped two tests purposely, and I can say we’ve gone back and looked at this,” says Wyant. “And so we’ve asked somebody in our laboratory. When the test comes in that doesn’t meet the protocol definition, they drop that test by definition alone, and so the reality is that’s how that sample got dropped.”

State officials say a sample from one home was dropped because there was a water filter. Homes with water filters are excluded because they might give a low result.

But the test result that was dropped –- the result from Lee Anne Walters home -- was the highest test result in the 2015 sampling pool: 104 parts per billion.

The second sample that was dropped showed 20 parts per billion of lead. The state says that sample was dropped because federal rules state that a sample can’t come from a business. It has to come from a home.

Spirit of the rule not followed?

So state officials say they made Flint drop test results because those samples didn’t follow guidelines.

But the guidelines for all the samples weren’t followed in the first place.

Federal rules say you must test the “worst-case-scenario” homes – the homes connected to pipes with lead in them. But the city didn’t do that.

Elin Betanzo is a water quality expert with the Northeast-Midwest Institute. She worked in the EPA’s drinking water office for eight years.

She says the rules say if a site is sampled – even if it’s not technically supposed to be in the sampling pool – the results should still be used to determine if the water supply is safe.

“If they did find high lead levels, that’s high lead levels in the water system. And the whole point of the rule is to be protective of public health for everyone consuming that water," Betanzo says. "So if one unplanned home is having high lead levels, that should factor into the compliance calculation.”

Marc Edwards says there are a lot of ways water utilities can "game" the lead and copper rule to try to turn up favorable results. In 2009, his team put out a white paper showing what he calls a list of "cheating strategies" used to get around the spirit of the lead and copper rule.

There are a lot of people looking into what was done in Flint. Governor Snyder appointed a panel to conduct a review. And EPA officials say they hope to share the results of their review sometime next week.

*Lindsey Smith and Rebecca Williams contributed reporting to this story.