Gwinnett County officials say residents have reported receiving fraudulent visits to their homes from people claiming to be county employees trying to gain access by offering free water testing from their taps.

The county tests water frequently, but does not send employees to test water inside of homes, county officials said in a press release.

About a dozen people have showed up to resident’s front doors trying to gain access, while three impersonators have made phone calls, a county spokesperson said.

Lake Lanier is the county’s source of water, and is it treated at Shoal Creek Filter Plant and Lanier Filter Plant. The water is also regularly tested at the Department of Water Resources Environmental Laboratory.

Residents with questions can call Water Resources’ 24-hour dispatch at 678-376-7000.