EBMUD says the stolen vehicle is identical to the hundreds of other maintenance trucks in is fleet.
The stolen vehicle contained $5,000 worth of tools, as well as an EBMUD work badge, hard hat, and safety vest.
The employee had been at a job site in Castro Valley, when he returned to his truck to find it gone.
The concern is that whoever stole the truck may pose as an EBMUD employee. Customers are being advised to take the proper precautions.
"People who are working on the streets don't ask to come inside your homes," said Nelsy Rodriguez with EBMUD. "Our crews won't be asking to come inside unless it's a prescheduled visit. In which case, please ask to see their identification number. And if you feel anything is suspicious please call us, or dial 911 if you feel threatened."
The truck was stolen Thursday and was last spotted Saturday night at the Redwood Christian Church in Castro Valley.
It's a white 2008 Ford F-350, vehicle #896, with the California license plate #1285077.
Anyone with information is asked to call EMUD. They're available 24 hours a day at 1-866-403-2683. Or notify your local police department.