By Sara Powers

(CBS DETROIT) – The levels of lead in Flint’s tap water has increased and officials are saying this is due to the increase in non-residential buildings being tested.

The Michigan Department of Environment, Great Lakes, and Energy (EGLE) announced Friday test results that show the city’s water maintained compliance with the state’s Lead and Copper Rule (LCR) during the lead pipe replacement project over the past year.

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The recent test results show that the 90th percentile calculation for the samples collected is at 10 parts per billion (ppb) for lead.

Officials say that the latest test results were higher than the previous 6-month test results, but it is still lower than the federal action level of 15 ppb.

In addition to this, EGLE says the increase is largely due to businesses, also called Tier 2 non-residential sites, being added to the testing pool, as the majority of the testing done was on homes (Tier 1) that have had their lead service lines replaced.

Officials say that  61 homes and businesses known to have lead service lines were tested.

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40 of these sites were single-family homes and other 21 were businesses.

EGLE reported that if only Tier 1 sites were tested the 90th percentile result would have been 7ppb and if only Tier 2 sites were used in the calculation the 90th percentile would have been 14ppb.

Many of the Tier 2 businesses tested were converted homes with older plumbing and low water usage, which can lead to higher test results.

“As Flint nears completion of its lead service line replacement program, we are seeing clear evidence that the focus will need to shift to interior plumbing and continued education on how to reduce lead exposures in the home as outlined on the state’s Mi Lead Safe web site,” said Kris Donaldson EGLE’s Clean Drinking Water Public Advocate.

Flint’s testing results can be found by visiting here and for any additional information about Michigan’s new testing requirements and for state-wide test results, visit here.

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