While Moulton City and water authorities have heard numerous complaints about foul water, Moulton Water Superintendent Jay Johnson said algae growth is the culprit, and an “earthy” taste or smell in the tap water is natural and harmless.
According to Johnson, the unpleasant taste and odor are temporary recurrences that happen about twice a year. He said Moulton Water Department has worked to verify the underlying problems and continues testing and monitoring its source water to resolve the issue now and prevent it in the future.
“The cause of the odd smell and taste is from naturally occurring compounds that are formed from algal blooms and other organic excretions,” Johnson said. “Although these compounds are harmless, the human sense of taste and odor are extremely sensitive to them and can detect them in the water at low concentrations.”
These algal blooms, which typically occur in Moulton’s raw water source every year in late spring or early summer and again late in the fall or early winter, produce two of the most common compounds that create noticeable flavor changes in the drinking water, Johnson explained.
These two organic compounds, geosmin and 2-Methylisoborneal (MIB), are responsible for the musty taste and smell, but otherwise pose no threats and are non-toxic to humans, according to sciencedirect.com. The source also claims geosmin is responsible for pungent earthy flavors in apple juice, beets, cereal, fish and wine.
Taste and odor issues brought on by algae growth are common challenges for surface water source systems across the country, Johnson said. The algae that produce these compounds, geosmin and MIB, usually form under extreme hot and dry conditions, which we typically see in early summer and late fall, he added.
Last year, when northern Alabama experienced an abnormally dry, hot October, Johnson said the conditions provided the perfect recipe for unusually high, longer-lasting algal effects, which resulted in longer-lasting, more notable flavor and odor changes.
“There are multiple tests being performed from an independent laboratory at this time that specializes in aquatic chemistry,” Johnson added. “We want to make sure we have a treatment plan in place that will ensure that we will be able to prevent and control taste and odor issues in the future. Our goal is to continue to provide high quality, safe drinking water to all of our customers.”
Johnson said Moulton’s water system, which sources its water from surface-level water from City Lake tributaries Sinking Creek and Turkey Creek in Langtown, continues to meet all state and federal water quality regulations.
“The water is safe to drink. We ask that all of our customers bear with us as we resolve this issue,” said Johnson.