Using research provided by the Environmental Working Group, the website 24/7 Wall St. said San Diego has 20 contaminants in the water supply, including trihalomethanes and manganese, a natural byproduct of industrial manufacturing, which can be poisonous to humans. Eight of the 20 chemicals exceed health guidelines, according to Daily Finance, while two other contaminants exceed the EPA's legal limit, the site said.
The test examined the quality of water in major American cities and covered 316 contaminants in water supplied to 256 million Americans in 48,000 communities in the United States. More than 200 of the contaminants used in the test, were chemicals not subject to government regulation, the site said.
The test based water quality rates on three separate metrics: the percentage of chemicals found based on the number tested for; the total number of contaminants found; the most dangerous average level of a single pollutant.
Number one on 24/7 Wall St.'s list was Pensacola, Florida.