In an annual state-mandated water quality report that was mailed to every city resident this week, the San Francisco Public Utilities Commission outlined facts about the city's household water supply, including its sources, potential contaminants and water quality regulations.
In 2009, the SFPUC Water Quality Division conducted more than 105,000 tests of drinking water quality throughout the 167-mile water delivery system running from the Hetch Hetchy, Alameda and Peninsula watersheds to San Francisco households, according to the report.
The drinking water supply provided by the watersheds and related infrastructure exceeded water quality standards set by state and federal regulators, prompting the U.S. Environmental Protection Agency and the state Department of Public Health to grant the environmentally protected Hetch Hetchy watershed a filtration exemption.
The water from Hetch Hetchy is so clean, according to officials, the EPA's exemption says that the SFPUC is not required to filter it.
"Every year this report confirms what our customers already instinctively know - that our water is one of the best in the nation," SFPUC general manager Ed Harrington said in a prepared statement.
"People should stop believing in the myth that bottled water is safer than tap water," Harrington said. "When was the last time a bottled water company issued a comprehensive water quality report?"