San Diego

San Carlos Residents Concerned About “Moldy” Tasting Water, City Says It's OK

People in San Carlos have noticed a change to their water and they’re worried it could make them sick.

Early this week the Next Door App was flooded with inquiries and complaints about the tap water in San Carlos. People describing the water as tasting “moldy” and “dirty.”

The water change appears to be limited to areas surrounding Cowles Mountain.

Stacey Poon-Kinney, the owner of The Trails Eatery near Navajo and Jackson, called the water “atrocious.” Poon-Kinney said the dirty tasting water is bad for her restaurant business.

“We actually got a Yelp review this morning about the water,” she explained, “they were so upset the water tasted so terribly they gave us a one-star review.”

According to the City of San Diego, the “earthiness” is caused by the organic compound Geosmin. Geosmin is found in surface water and is not toxic or harmful.

See the full statement from the city here:

“San Diego drinking water is safe to drink. The city’s water continues to meet all state and federal water quality standards, but we have been experiencing a temporary change in the taste and odor of the water being produced at our Alvarado Drinking Water Treatment Plant. The primary taste and odor variant is caused by an organic compound called Geosmin (from the Greek for “earth odor”). Geosmin is a naturally occurring compound in soil and algae found in surface water. While the taste and odor can be unpleasant to some, geosmin is NOT toxic or harmful. Regular ongoing water quality testing continues to show our drinking water meets all state and federal standards for the protection of human health. Computers at the treatment plant monitor the water 24 hours a day and manual tests are performed by plant operators and the water quality lab.

During normal water system operations, the department uses a variety of water sources including imported and local water supply. Recently we have been using a higher percentage of local water from our existing reservoir system. This change in water supply has contributed to increases in the amount of geosmin in the water which changes the taste and odor of the water currently being delivered.

Of note, humans are particularly adept at detecting geosmin with a wide range of sensitivity between individuals. Some customers may note the difference in taste and odor, while many may not. Also, the warmer the water, the more evident the odor and taste may be so it is very common to notice when in the shower or heating up water for cooking.

Geosmin is common in many jurisdictions across the United States, Canada and elsewhere in the world.

The Alvarado Drinking Water Treatment Plant distributes generally to the areas of the City bounded by Hwy 52 on the north, city limits to the east and Hwy 54 to the south. It is possible over the next few days that customers throughout this distribution area may notice this temporary change in taste and odor, but it should end soon.”

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