Ever since the state admitted there was a problem with Flint's drinking water, we all have been waiting for more information about how bad – how widespread – the problem might be.
Many people in Flint have been practically screaming that their water is bad for almost two years. When outside researchers and experts finally convinced state leaders to do something, one of the first things they did was to push people to get their water tested.
People in Flint can pick up lead testing kits for drinking water for free at local fire stations (they can also pick up free bottled water and water filters).
Thousands have had their water tested, and the state has been publishing the results of those tests in an excel spreadsheet.
We mapped the results of these lead tests for the month of January. These are tests of people's drinking water more than two months after the city switched back to Lake Huron water from Detroit.
We could confirm the addresses of 4,051 drinking water tests in Flint for the month of January. We grouped the lead results into six ranges.
- 0 ppb - no lead detected in the drinking water
- 1-4 ppb - the EPA deems this range as acceptable
- 5-14 ppb - exposure is a concern, but still below an EPA "federal action level"
- 15-49 ppb - a range above the federal action level for lead, but can be treated by filters
- 50-149 ppb - reaching dangerous levels, but can be treated by filters
- 150 and above - a range at which the federal government says water filters might not work
See the map below - or see a full version here (click on a dot for ppb lead result and address):
You can see that no real pattern emerges.
Officials have their work cut out for them in determining the sources of the lead problem in these homes.
It should be noted that these 4,051 samples from around the city were randomly collected in the month of January.
They do not represent the potential for the "worst-case" scenario homes – homes connected to drinking water lines known to have lead in them.
City officials don't know where those water lines are. It's something they are working on now. Because they don't know where those lines are, it's more than likely the city has not been following the protocol under the EPA's "Lead and Copper" rule for some time. That rule requires cities to watch these homes where lead could be a problem.
(Read more about that here.)
Even so, the sheer number of samples collected does begin to paint a picture in Flint (so far, a random one).
Mark Durno is the on-scene coordinator for the Environmental Protection Agency in Flint. He says they're getting a good size sample pool of the roughly 30,000 homes in the city.
"Normally when we collect samples that are representative of an entire system, it's not nearly this robust," says Durno. "Even with only 5,000 data points out of 30,000, that's a pretty strong indicator of what we're seeing in the system."
Durno says they're encouraging more people to have their water tested. He says it will help them figure out what's going on, and it will help them identify the trouble spots.
Here's how the numbers break down from the 4,051 samples we mapped above:
- 0 ppb - 52.7%
- 1-4 ppb - 30.5%
- 5-14 ppb - 10.4%
- 15-49 ppb - 4.2%
- 50-149 ppb - 1.3%
- 150 and above - 0.8%
The state has more recent data here.
The Michigan Department of Environmental Quality says it's working on a water testing plan that will help determine when the water in Flint will be safe to drink again. We should hear more about that plan in the coming weeks.
*Thanks to Cass Adair, Elias Brush, and the folks at SmartyStreets for their help in mapping this data. Additional reporting from Rebecca Williams.