Major U.S. utilities' methods for testing the quality of water were recently investigated by The Guardian and found to be "improper." Utilities distort these tests by asking customers who sample their home’s water for lead to remove the faucet’s aerator screen and to flush lines hours before tests, potentially flushing out detectable lead contamination.
According to the Environmental Protection Agency, these improper screenings could decrease the chance of detecting potentially dangerous levels of lead in water. They also note that these methods have been used in major U.S. cities including Chicago, New Orleans, and Philadelphia.
Michigan Live explained the dangers of using first draw methods which are currently being scrutinized:
“Unfortunately, first draw samples are not typically catching the water in the lead service lines, said Daniel Giammar, an environmental engineering professor at Washington University in St. Louis, Mo. Ideally, sampling should collect as many as 20 sequential liters from a tap that has the aerator removed, he says,” Michigan Live reported.