Earthy drinking water smell, taste caused by algae
MANATEE COUNTY – If you’re noticing a musty or earthy taste or odor in your drinking water, it’s being caused by algae that grows in all lakes, including Lake Manatee, the source for two-thirds of the county’s drinking water, according to county officials.
“Customers of Manatee County Utilities may notice a temporary and non-harmful change in their water taste or odor. Algae blooms are regular seasonal occurrences in Lake Manatee but vary in frequency and duration,” according to a June 21 press release from Manatee County.
“Current conditions favor a bloom, and tests conducted over the past several days indicate the presence of algae at elevated concentrations in Lake Manatee. This can create an earthy and/or musty taste or odor in the treated drinking water. While the odor or taste may be noticeable, the water remains safe to drink.”
“We will continue monitoring and conducting treatment efforts until water quality returns to normal,” Manatee County Utilities Deputy Director Katie Gilmore said. “It is our hope that by informing the public of this algal bloom, we can alleviate any concerns that may arise should a customer experience taste or odor issues in their drinking water.”
The county has implemented a treatment process that involves the addition of powdered activated carbon.
“This process is very effective in the removal of taste and odor-causing compounds. However, when the levels reach quantities that exceed the limit of the systems’ removal capability, customers may notice a slight earthy/musty taste to their water,” the press release stated.
“The water remains entirely safe for consumption. If desired, customers can utilize a carbon filter hooked up to the faucet to the water system of the refrigerator or a filter pitcher designed for taste and odor removal to help minimize the off-taste and/or odor,” the release said.
According to the Manatee County online Water Odor and Taste Fact Sheet, “Certain algae and bacteria produce compounds (MIB Methyl-Isoborneol and geosmin) as part of their metabolism that impart the earthy/musty odor/taste to the water (These same compounds are produced by bacteria in soil and make ‘dirt smell like dirt.’). The compounds do not affect the safety of the water but produce odors at very low levels (part per trillion).”
The algae blooms occur most frequently in late spring and early summer. They occur two to three times a year and last between two and four weeks.
