Study reveals contaminated groundwater

A decade-long U.S. Geological Survey found that almost one-fifth of California’s raw groundwater – that’s primarily used as drinking water – contains excessive levels of harmful contaminants. This study is the first comprehensive look at the state’s groundwater and drinking supply. About one-third of the state’s drinking water comes from groundwater in public supply wells.

High levels of arsenic, uranium and other trace elements are present in the 11,000 public supply wells that were used for this study. For the purpose of this survey, a public water supply is considered a water supply that provides water for 3 or more people.

While public agencies are required to bring contaminants down to safe consumption levels, wells that sit on private property don’t undergo the same scrutiny. It’s up to the individual property owner to make sure the drinking water is safe for consumption. The study found that more than 250,000 private wells could have potentially high levels of harmful contaminants.

“The survey also gives public-policy-makers the first sweeping look at the extent to which agricultural irrigation, industrial pollutants and other uses of groundwater are adding to problems for underground water reserves, now under heavy demand in California’s drought,” a report for The Associated Press reads.

The study has found that agriculture has played a major role in the increase in uranium levels in underground water aquifers, which has made the drinking water unsafe. 7 percent of public water supplies in the Central Valley have been deemed unsafe for consumption, according to the survey.

Although the Water Resources Control Board is concerned with safe drinking water, the board cites the California drought as a major culprit in the contaminants. According to John Borkovich, an official at the State Water Resources Control Board, the California legislature would have to decide how to handle continual culprits who frequently contaminate drinking water.

“By law, public water systems with a well that consistently shows unhealthy levels of contaminants are required to notify customers and fix the problem, said Kurt Souza of the State Water Resources Control Board’s division of drinking water,” a report by The Associated Press read.

According to the survey, one major factor was discovered: areas that were once used for farming and then turned into suburban areas tend to see unsafe levels of nitrates in their groundwater. The unsafe levels come from fertilizers that cloud raw drinking water.