Columbia Water tweeted May 17 that they were aware of an issue with the tap water having an "earthy smell or taste." Columbia Water says the water is safe, but almost three weeks later, the water is still earthy and experts are unsure of when it will return to normal.
Robert Yanity, the communications manager for Columbia Water, said the odor is naturally occurring in the environment and is produced by geosmin, a compound that is produced when things like algae break down in water.
Yanity said geosmin is always detected in the water, but never at the current amount.
"We've never seen a spike this high in geosmin, and we can't pinpoint the exact reason we're seeing the spike," Yanity said.
Columbia Water is treating the water with activated carbon, which acts like a sponge to get rid of the geosmin.
The amount of geosmin has fluctuated since May 17. Yanity said after the initial spike it was treated and brought down to "reasonable levels," but then spiked again numerous times, with the biggest spike over Memorial Day weekend.
Susan Richardson, a USC chemistry professor who studies contaminants in water, said she is not sure why it has taken so long for the geosmin levels to subside after being treated with activated carbon.
"I would have naively thought like in a day, two days max, this would be gone," Richardson said. "I don't know quite why it's taken so long to overcome this."
Columbia Water sources its water from two places, Columbia Canal and Lake Murray. Yanity said only water coming from the canal is affected by the geosmin as the canal sources its water from the Broad River.
Two other towns, West Columbia and Cayce, which both get their water from the same source, are also experiencing the odd smell and taste.
Yanity said Columbia Water is planning to apply copper sulfate to kill the algae at the source. This plan first has to be reviewed by South Carolina's Department of Health and Environmental Control and was approved June 6.
"We are looking to add another feed system to our treatments that will allow us to add a copper sulfate formula to the water," Yanity said. "Activated carbon, that usually does the trick with the levels we've seen in the past, but with this big spike, it's really hard to treat it with just the activated carbon."
The Columbia Water Twitter account tweeted June 7 that it is difficult to determine the impact of these efforts, but it takes four or five days for water treated at the canal plant to make its way entirely through the distribution system.
Aditi Bussells, an at-large member of Columbia's city council, is the chair of the Environment and Infrastructure Committee. Bussells said the water department is confident they can resolve the smell over the next couple of weeks.
"If people can't drink water because it just tastes horrible, that's a problem," Bussells said.
Yanity said he hopes the copper sulfate will solve the issue but he's not sure how long it will take for the water to be rid of the earthy smell and taste.
"It's going to be something we'll have to continually treat, so (it is) hard to pinpoint a time of when it's going to be taken care of," Yanity said. "We're working as hard as we can to get it taken care of as quickly as possible."