SACRAMENTO - California is digging deep to get the drinking water it needs after one of the state's worst droughts on record.

The problem is that the groundwater it is using is unsafe for nearly 800,000 residents, according to the state's water resources control board, because of longtime contamination from nitrates and arsenic.

That's meant less drinkable water in California's struggle to survive more than three years of severely dry weather.
"Most areas affected by contamination don't have surface water supplies so they have to find new groundwater sources," said Kurt Souza, a branch chief of the division of drinking water at the California State Water Resources Control Board.

"But that's not always easy to do," Souza added. "Sometimes you can find new ground locations for water and sometimes you can't."

The lack of rain and subsequent heavy demand on ground wells—which are also facing supply problems—is making a bad situation worse, said Sara Aminzadeh, executive director of the California Coastkeeper Alliance, a statewide advocacy group for safe water.

According to the state water resources study, unsafe levels of arsenic are the top contaminant in groundwater supplies, followed by nitrates.

Nitrates are most often traced to farming chemicals and animal waste. Arsenic is found naturally in soil and rock in much of the world and seeps into groundwater.

Chronic low exposure to arsenic has been traced to respiratory problems in children and adults as well as having links to diabetes, cardiovascular diseases and cancers of the skin.

"Arsenic is a known carcinogen and with increased reliance on groundwater in California, the risk of arsenic increases," said Chris Williams, a hydrologist and terrestrial ecosystem ecologist at Clark University.

‘We have had contamination’

California seems particularly vulnerable to arsenic contamination, said Francie Cuffney, head of the biological science department at Meredith College.

"It has areas of high arsenic concentration. Groundwater in contact with rocks of high arsenic concentration will naturally leach out arsenic," Cuffney added.

The state water resources board said 98 percent of the 38 million Californians get safe drinking water from public sources and treated groundwater supplies.

But 772,883 Californians rely on groundwater that is contaminated due to the high cost of water treatment or a lack of alternative water sources, according to the board.
Of that number, 400,000 are in the San Joaquin Valley—often referred to as the "food basket of the world" for its agricultural production. (Source: NBC)

Story Date: October 27, 2014