Recent visible changes in central Arkansas drinking water were caused by a strong wind event in a reservoir and are not considered harmful, according to a utility company official.
Randy Easley, director of water quality at Central Arkansas Water, said a wind shift that began Sunday night and became intense late Monday caused mixing within Lake Maumelle.
Strong wind changes over a lengthy period of time can cause alterations to the layering of cold and warm waters, or stratification, from the lake’s top to bottom, Easley noted.
He said that in turn results in some dissolved minerals and metals coming closer to the surface and entering the water treatment system.
According to a company statement, mixing can “cause subtle changes in taste and, at times, short durations of discolored water, created by increased manganese levels.”
The manganese is not considered a health concern. In this event, the change in wind caused some customers in central Arkansas to see a light yellow hue in their water supply.
Easley said the utility company noticed the changes Tuesday, noting that it takes up to 10 hours for water from the lake to get to the treatment plant.
Water treatment officials on Wednesday successfully brought the water to conditions that the Environmental Protection Agency considers acceptable, according to the company.
As of Thursday, the water supply was “getting back to normal,” the water quality director said.
The visible changes in drinking water were not the result of seasonal “turnover” in the lake, as Central Arkansas Water had previously mentioned Tuesday, Easley said.
Lake Maumelle, a 13.9-square-mile reservoir in western Pulaski County, typically exhibits mixing patterns five to six times a year, he added. The reservoir provides about 65 percent of the daily demand for the Central Arkansas Water system, which serves a population of nearly 400,000, according to its website.
Another water supply for the utility company, Lake Winona, showed no recent signs of visible mixing, Easley said.