Musty/Earthy Taste in Water No Cause for Concern
Author: Public Works
Date: 10/30/2026 3:22 PM
Residents that receive water from the Lopez Water Treatment Plant (WTP), including the cities of Pismo Beach, Arroyo Grande, Grover Beach, Oceano, Avila Beach, and Shell Beach, may notice a musty or earthy taste or odor in their drinking water. The water remains safe to drink.
“We understand that some residents are sensitive to changes in taste or smell,” said Nola Engelskirger, Water Utilities Division Manager. “This type of taste and odor change is normal for surface water systems and can occur from time to time. We continue to monitor and assess the situation, and your water remains safe to drink.”
The taste or odor changes are caused by natural compounds produced primarily from algae and organic matter in surface water from Lopez Lake, the source for Lopez WTP. These compounds can create a musty or earthy taste and odor. Although some customers may find this unpleasant, they do not present any health risk. They are routinely monitored and regulated only as an aesthetic concern and not as a health concern.
The WTP is increasing water monitoring and testing and adding powder-activated carbon (PAC) to the treatment process to help remove the compounds causing the taste and odor. The water supply is perfectly safe to drink and no water quality standards are being violated.
This change in taste is not related to the upcoming annual switch to free chlorine disinfectant, which will take place November 4 through December 2, 2026. During that time, residents may also notice a slight difference in taste or smell though the water is safe to drink. This annual process of alternating disinfectants from chloramines to free chlorine helps keep the water system clean and operating safely. You can learn more about the upcoming switch here: https://www.slocounty.ca.gov/departments/public-works/department-news/2026/county-to-temporarily-switch-drinking-water-disinfectant-to-free-chlorine-in-the-five-cities-area
