Water officials attribute to natural occurrence; riverkeeper blames sewage spill
Residents near High Rock Lake in North Carolina are scratching their heads wondering what killed thousands of fish strewn about the shores of the lake, reported the Salisbury Post.
State water quality officials said the event was just a natural occurrence, according to the Salisbury Post report; but Dean Naujoks, the Yadkin riverkeeper, told the Salisbury Post he believes the fish deaths were connected to a 15.9 million gallon sewage spill that occurred earlier this year in Thomasville, N.C.: Since early August, the sewage had been spilling into North Hamby Creek, which feeds into High Rock Lake, the Salisbury Post reported.
Naujoks said the sewage likely settled into the sediment near the High Rock dam, according to the report.
But Dr. JoAnn Burkholder, a water quality expert at North Carolina State University, disputed the possibility of this, and according to the Salisbury Post, said a sewage spill of that magnitude would linger on the lake bottom for up to six months.
Still, Naujoks is convinced something disturbed the water to churn up the sewage, which could deplete oxygen in the water and kill the fish, the Salisbury Post reported.
"There's no way to prove it,” he told the Salisbury Post. “But, in my opinion, when you have a sewage spill of 15 million gallons, it's going to rob this lake, which is already struggling, of oxygen; and it likely contributed to this fish kill."
The water quality officials attributed the fish deaths to a “turnover” event when low dissolved oxygen goes through the entire water column, due to changing temperatures and storms; and fish suddenly are caught in low oxygen areas, officials told the Salisbury Post.
Further, the Salisbury Post reported that, according to the North Carolina Division of Water Quality, a state investigator tested the water on the lake following the fish deaths, and found no evidence that wastewater was the culprit.