Many California water districts rank near the bottom in a new study released this week on the quality of drinking water throughout U.S. large cities.

The city of Riverside Public Utilities (serving 280,832 people) ranked all the way near the bottom at No. 99 out of 100 on the list.

In Riverside, the EWG found 19 chemicals that exceed health guidelines, five chemicals that that were health standard exceedences and 34 chemicals with pollutants found.

The Environmental Working Group ranked water utilities in cities with populations more than 250,000 based on three factors:

  • the total number of chemicals detected since 2004;
  • the percentage of chemicals found of those tested;
  • and the highest average level for an individual pollutant, relative to legal limits or national average amounts.

Riverside County ranked at No. 97 and San Diego County is No. 92 on the list. Los Angeles (Los Angeles Department of Water and Power, serving 979,000 people) was No. 83 on the list.

“Looking at the data, we’re definitely concerned about water quality in Southern California. We recommend utilities really look at their processing. There’s much room for improvement,” said Olga Naidenko, a senior scientist at the Environmental Working Group, a nonprofit environmental watchdog based in Washington, D.C., and a co-author of the report, according to the L.A. Daily News.

“We recommend residents get water filters.”

It wasn’t all bad news in California. The state’s capital, Sacramento, ranked at No. 18 on the list as the highest rated California city. San Francisco was No. 33 and Oakland was No. 36. The highest-ranking Southern California water district is the Long Beach Water Department at No. 40.

In a statement, Jane Houlihan, senior vice president for research at Environmental Working Group, said, “The nation’s tap water has been compromised by weak federal safeguards and pitiful protection of drinking water supplies,” said in a statement.

For a full list of the rankings, visit the EWG Web site, by clicking here.