This is a total scam. You get a postcard that says:  "Water Update. Unfortunately,  we have been unable to contact you by phone or home visit. Please contact us within the next 72 hours. Call Mrs. Brown Between 9:00 am - 9:00 pm - Monday  thru Friday, 9:00 am - 1:00 pm - Saturday  954-865-4199 Thank You."
They have nothing to do with your water utility. They're trying to sell you some bogus, worthless stuff. The fact they need to trick you into calling them within  72 hours tells you it's a setup.

The various water utilities already have scam alerts out on this scheme.