Over the next seven weeks, the state will test more than 400 sites for copper and lead.
"This was an effort to look back on the health of the system, and so that's why we're doing it repetitively," said Keith Creagh with MDEQ. "Every two weeks we're going to take a sample, and we're going to see what happens with those numbers."
The first round of results is in.
Out of 175 samples, 89% were below the state's action level, but 11 percent of homes exceeded the action level of 15 parts per billion, with five homes exceeding 100 parts per billion.
The governor says it's not time to draw conclusions.
"This is where we don't want to overread into this because we don't know what they were even going back a year or two," said Governor Snyder.
That's why the state sends in a team to do more testing for homes with higher lead levels.
"We have a plumber on the team, we have other resources on the team to go through and do an analysis in the home with the homeowner's permission to clear the aerator, look at the whole process, and say can we help identify if there's a specific issue that's creating the problem to get that high lead level," explained Snyder.
An ongoing process as the state waits for results from a month long study to find and replace lead service lines.
"If there's discrepancies, that means there's more work to be done to find out what the answer might be," said the governor.
And how much it'll cost to get the job done.