Birmingham Water Works says levels of compound that causes ‘earthy’ taste ‘have dropped significantly’

A compound that makes drinking water taste “earthy” has “significantly decreased” in portions of Birmingham Water Works’ territory, the utility said Friday.

“On May 20, BWW was notified that customers in the UAB area, North Hoover, Homewood, portions of Vestavia Hills and Mountain Brook were experiencing earthy tasting water. We are pleased to inform you that geosmine levels in our water supply have decreased significantly, although some customers may still notice a slight earthy taste,” the company said in a statement Friday afternoon. “Our water quality team will continue to diligently monitor and test water to ensure its quality and safety for all our customers.”

A BWW spokesman could not immediately be reached to quantify geosmin levels in the water.

Earlier this week, residents of several Birmingham suburbs began complaining of a “nasty” and earthy taste in their drinking water.

Birmingham Water Works has seen complaints from customers in northern Hoover, Homewood, Mountain Brook, portions of Vestavia Hills and the UAB area.

“Our sampling indicates elevated levels of geosmin in drinking water, which is responsible for the recent taste and odor questions. Geosmina is a natural compound,” he said in response to Wednesday’s complaints.

“There are no negative health effects associated with consuming geosmin. It is geosmina that gives fresh grapes, wines, beets, mushrooms and carrots their earthy smell and taste,” the statement continued. “Drinking water utilities around the world that use rivers, lakes and streams as sources of drinking water production often experience fluctuations in geosmin levels due to seasonal changes, particularly in the spring.”

According to the American Chemical Society, geosmin is a naturally occurring “bicyclic terpene” with an “earthy odor.”

The human nose can detect it at airborne concentrations of up to five parts per trillion. It’s why a beet smells like a beet.

It was first described in 1936 in London and named by scientists at Rutgers University 30 years later, from the Greek words for “earth” and “smell”.

Birmingham Water Works says tests show the water is safe to drink.