This kit failed to tell how to DISINFECT the faucet end BEFORE one took water sample in order to make the bacterial test legitimate. I got a positive on the bacteria, which scared me. BUT, it came out negative when the local public health re-did it. The Public Health kit requires firing (sterilizing) the faucet with a barbecue or cigarette lighter before ANY testing, AND to run the water for 10-15 minutes before taking samples for any test.