Water officials across Northern California are issuing warnings about individuals going door-to-door falsely claiming that local tap water is unsafe.

Several water agencies, including the Citrus Heights Water District, Sacramento Suburban Water District, Orange Vale Water Company, and California American Water, have reported a rise in these unauthorized solicitations in neighborhoods like Sacramento, Citrus Heights, Carmichael, and Roseville.

"We received multiple phone calls reporting this in our service area," said Mary Elise Conzelmann, Principal Public Affairs Analyst for the Citrus Heights Water District. "These individuals are not affiliated with any of our agencies."

Scammers are knocking on doors, telling residents that their water is unsafe, and then attempting to sell expensive water treatment systems. Officials stress that this is false — your water is safe.

These individuals may attempt to enter homes under the guise of testing the water, which no official water agency would do unless an appointment was scheduled in advance.

"Residents should decline unauthorized offers to test water inside their home," said Conzelmann. "Ask for ID and call your water provider directly if in doubt."

Homeowner Colby Silvernail, who lives in one of the affected districts, shared his approach to unexpected solicitors.

"If they come up to my door, I'd say, 'Oh, thank you for your time, but I'll do my own research,' " he said.

Water officials recommend the following steps if you're approached:

• Do not let unsolicited visitors inside your home

• Ask for official identification

• Call your local water provider to confirm

• Report suspicious activity to authorities