Geosmin Fouls Up Silicon Valley Tap Water

Water officials in California’s Silicon Valley say algae blooming in the Sacramento-San Joaquin Delta is to blame for strange-smelling tap water in recent weeks.

“Some people might notice a dirt-like smell or taste in their tap water, and that is because of a bloom of algae” releasing geosmin, Colleen Valles of the Santa Clara Valley Water District said, per KCBS.

“The Water District had already switched its source from the Delta to the San Louis River until the problem is resolved,” KCBS reported.

The report said ratepayers can cool their water to a low temperature to reduce the flavor. Milpitas, San Jose, and Mountain View were among the cities affected, according to ABC 7.

"Our water is still safe. It's still healthy. If people do detect odor or taste, they can chill water. That will help mitigate it," Valles said, per ABC 7.

The algal bloom is producing geosmin, the report said, which creates an earthy taste. This kind of bloom is not toxic, according to the U.S. EPA.

“Blooms produce a variety of odor and taste compounds, such as geosmin and 2–methylisoborneol (MIB), which are not toxic but are a nuisance to the public. The cyanobacterial genera that are known to produce geosmin are Anabaena, Aphanizomenon, Lyngbya, Microcystis, Oscillatoria, Phormidium, Schizothrix and Symploca; however, taste and odor issues are complex and are not solely associated with the presence of cyanobacteria,” the EPA says.

Scientists have been monitoring algal blooms in the Delta, which housed sizable growths last year, as well.

“In what researchers suspect is another troubling side effect of the state’s epic drought, the Delta is exploding with algae particles that in intensified concentrations could pose a substantial threat to the central hub for California’s vast water delivery network,” The Sacramento Bee reported last year.

To read more about algal blooms visit Water Online’s Nutrient Removal Solutions Center.