We have a consumer alert tonight, involving a water filter scam. Tallahassee authorities say people are posing as city water system employees, asking homeowners to sign up for a water quality test.

Tallahassee water managers say a market research firm is behind it, because they've been hired by outside water filter companies to find new customers.

Managers with Tallahassee’s water quality control office say they've been getting a lot of calls about people claiming to be city employees, going door to door, trying to test their water.

"They're asking customers to schedule a water test. So they get a customer to sign a piece of paper and then one of these filtration companies will call the customer back later on and set up an appointment."

Investigators say the door-to-door approach is just a new way to get around the National Do Not Call List.

"This is just one of several Tallahassee neighborhoods target by the door to door campaign. The experts say they have several tips to help you protect yourself from this kind of fraud."

"With any person that comes door to door, you should always ask to see some kind of id. Whether it be a city employee or a private consulting firm. That's really a must. Also, if you sign a piece of paper, you should always get a copy of it you should always know what you are signing, before you sign it."

"Don't sit there and trust them, they might be telling you the truth, but I highly doubt it. I wouldn't sit there and listen to everything they have to say. Basically go, okay. Not interested. Turn around and shut the door."

Water managers say if you have any questions about your water, don't wait for someone to knock on your door, simply call your water providers. In Tallahassee, that number is 850-891-4968.

Water managers say there have not been any changes in water quality and that tap water remains safe to use.