‘Unprecedented’ algae levels stink up Columbia’s water. Here’s why the city say it’s safe
In early May, Columbia water customers began complaining about musty smelling and bad tasting water from their taps.
City officials have worked to fix the problem, but residents are still noticing a bad taste in their water.
The water is safe to drink, Columbia Water officials have stressed.
The cause stems from compounds in naturally-occurring algae growth during summer months that are common in the Broad River and Lake Murray. One of those compounds in particular, geosmin, is showing up in unprecedented levels, according to a release issued by the city’s water department.
While it’s not toxic, the human senses are incredibly sensitive to geosmin. It takes very low concentrations of the compounds to produce a change in how your water tastes or smells. Humans can detect the compound in as low concentrations as five parts per trillion, according to Columbia Water.
Over the Memorial Day weekend, the concentration hit 223 parts per trillion. Water officials say it’s rare to see those level reach even 25 parts per trillion.
“Although we cannot pinpoint the exact reason for this, we do know that algae, which produces geosmin, thrives in hot temperatures, low water levels, and still or slow moving water,” the water department release states. “We have experienced all three in recent weeks on the Broad River above our Canal Plant intake.”
Department of Health and Environmental Control tests indicated the high levels of algae are not a harmful algae bloom, Robert Yanity with Columbia Water said. Harmful algae blooms can contain toxins dangerous to humans and animals. The DHEC testing showed that isn’t a concern here, Yanity said.
Geosmin is difficult to remove from water during the normal treatment process. Water officials are using activated carbon, which works like a sponge to remove the compound.
The department is also using a chemical approach approved by DHEC to reduce the amount of algae in the source water.
The city is also flushing its systems and encourages residents with immediate taste or odor problems to contact the department at 803-545-3300.
In a statement late Friday afternoon, DHEC said it has confirmed the presence of algae-related compounds that are causing odor and taste concerns, even though they are not harmful. The agency said an algal bloom in the Broad and Congaree rivers is to blame for the problems.
“DHEC has been working with the water systems on actions to correct the problem, and DHEC is ensuring that any treatments the facilities use to address the algae-related compounds are approved for use in drinking water system,’’ the agency’s statement said. “DHEC will continue to work with the drinking water systems as well as monitor the situation.’’
This story has been updated with a statement from DHEC.
Staff Writer Sammy Fretwell contributed.
This story was originally published June 3, 2022 at 2:59 PM.
CORRECTION: An earlier version of this story had an incorrect phone number for Columbia Water’s customer care center. The phone number is now correct.
