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City utility says there’s no pesticides in SF water

Well, that’s good to know

water pouring into a drinking glass. Photo by science photo/Shutterstock

On Thursday, San Francisco’s Public Utilities Commission [PUC] announced that after a battery of tests the city has discovered “no signs of pesticides” in the water supply.

This sounds like an almost suspiciously specific denial when considered out of context. But it turns out that some people in the city’s westernmost neighborhoods have been asking about it:

Earlier this month, some residents in the Sunset District noticed a change in taste and odor in their tap water, prompting them to use a home water quality testing kit. Some of the kits reportedly detected pesticides in the water.

In response, the SFPUC collected more than 20 water samples, including ones from wells, distribution monitoring points, a customer home test kit site, area schools and Sunset Reservoir.

“At no time was the water unsafe to drink,” according to the PUC’s statement.

Publicly released data shows 22 samples collected on October 9, which then went through tests for 17 potentially hazard substances. None of them revealed anything worrisome, at least according to the city’s own aquatic audit.

According to the city’s 2017 Water Quality Report, SF’s water supply stood up to “more than 101,900 drinking water tests in the transmission and distribution systems” that year.

A drained cistern in the Mission. (Probably not used for potable water storage.)
Photo by Robin Scheswohl

The results reveal that there are probably a few odd additions to city cisterns, but it’s not necessarily anything to worry about:

Drinking water, including bottled water, may reasonably be expected to contain at least small amounts of some contaminants. The presence of contaminants does not necessarily indicate that water poses a health risk.

In order to ensure that tap water is safe to drink, the [federal government] prescribe regulations that limit the amount of certain contaminants in water provided by public water systems.

Soil runoff sometimes adds unwanted substances to SF drinking water, according to the report, but not to any degree that should brook concern.

And as for the Sunset’s funny-tasting founts? Assuming it’s not just the power of suggestion at work, Cooks Illustrated writes that most of the flavor of water is “due to minerals and other compounds that the water picks up on its journey” through local plumbing.