WASHINGTON -- Valley health officials insist that it's safe to drink the water, but area residents don't appear to be so certain.
A recent Census Bureau survey showed that 17 percent of residents in the Phoenix-Mesa-Scottsdale region believed the primary water source in their home was unsafe in 2011. While that's down from the whopping 27 percent of Valley residents who thought the water was unsafe in 2002, the last time Census asked the question, it was still more than twice the national average of 8.1 percent in 2011.
Health and environmental officials believe it's a perception problem: The water is as safe in the Valley as anywhere else, they say.
"There are more than 5 million tests and measurements performed every year to make sure the drinking water meets those EPA (Environmental Protection Agency) requirements," said Ken Kroski, a spokesman for the Phoenix Water Services Department. And those are tests in Phoenix alone, he said.
Mark Shaffer, spokesman at the Arizona Department of Environmental Quality, said the data from his department "does not support that 17 percent of housing units in those cities received ‘unsafe' drinking water."
"There were no violations of maximum contaminant levels in public water systems serving more than 2.2 million people in Phoenix, Mesa and Scottsdale in 2011, 2012 or thus far in 2013," Shaffer wrote in an email.
Bill Reed, coordinator of the state Department of Environmental Quality's Safe Drinking Water Program, chalks it up to misconception on the part of consumers.
"It could be that the water doesn't taste good or look good, but that doesn't mean it's not safe," said Reed, noting that cloudy water can still be safe and drinkable.
The water-quality numbers were part of the Census Bureau's 2011 American Housing Survey of 155,000 homes nationwide that created a portrait of the nation's housing stock on a broad range of characteristics, from cost to age to number of rooms and number of cars.
The water-safety question asked people whether or not they thought their drinking water was safe. The survey excluded housing units where the primary source of water was commercial bottled water.
Brian Sullivan, a spokesman at the U.S. Department of Housing and Urban Development, which participated in the survey with Census, noted that the water-quality question was subjective.
"We asked people if they believed their water is safe," said Sullivan, noting that the department did not test the water quality to make sure.
Because the question does not actually answer the question -- is the water safe? -- Sullivan said the department is considering dropping it from future surveys.
Julia Gargano, a drinking water epidemiologist at the Centers for Disease Control and Prevention, said public water supplies are usually safe and that drinking water quality has been improved substantially.
"Regulations enacted in the last decade have really reduced the risk of outbreaks from public water systems," said Gargano.
Gargano is not so confident about water from private sources, such as wells.
"People who get their water from a private source need to be proactive about maintaining their well and testing their water, because it's homeowners' responsibility," she said.
Valley homeowners in the survey were less likely to question their water than renters, with 14.7 percent of owners responding that the water was unsafe compared to 21.2 percent of renters.
Gargano suggested that there are a few things people could do if they have doubts about the quality of their drinking water.
"If people are curious about their public water supply, they can obtain a consumer confidence report from their water utility, and if they have concerns about a private well, they can contact their local health department for information about testing," she said.
Kroski said the water department tries to get information on water safety "out to our customers as much as possible through different sources."
"We do the best that we can to let them know that we do meet those requirements," he said.