Town of Berryville Director of Utilities David Tyrrell announced last week that the town's water plant was cited for a violation for a "Disinfection Byproduct Precursor (DBP) Treatment Technique Requirement."

Tyrrell explained that the violation, which the Virginia Department of Health requires the town to file, means that due to a sample taken in October, the running yearly average of total organic carbon removal ratio is less than 1.00, with a ratio of 0.93.

In simple terms, he said, it appeared that the readings for the month of October were reversed.

"The raw water looked treated, and the treated water looked raw," he said.

Tyrrell emphasized that Berryville residents need not worry about the quality of their water.

"This is not a health hazard, and there are no health effects that can result from this violation," he said.

Typically, he said, the plant's water quality is very good, and three additional tests taken after the October test all indicated normal results. He said he's uncertain what caused October's unusual results.

Tyrrell said there are several possible explanations: the sample vials could have been mislabeled, the state lab could have made a processing error, the sampling vials or glassware could have been contaminated, or the results could have been correct.

The state maintains that it reported the test results correctly, Tyrrell said, and he also has utmost confidence in the operator who collected the samples.

"There's no way to verify it, so we have to call it a violation," he said. "It has never happened before or since in 22 years of service."

Tyrrell explained that the reason why the October test results were not released until February was because the town could not know of a violation until all results for the quarter were tabulated. He said that results prior and since were all fine, so the October reading was the only factor that caused the violation.

Another reason why it seems unlikely that the results are correct, Tyrrell said, is that the total organic carbon levels in the Shenandoah River are normally very low.

"If the results are correct, there must have been a dramatic change in the river water quality," he said.

The mystery of what happened with the test results may never be solved. But with the town's clean track record, it seems likely that future tests will continue to show that Berryville's water is safe.

"This facility delivers a quality product routinely," Tyrrell said in a statement presented to the Berryville Town Council.

The town must complete a public notice to inform customers of the violation by Feb. 23, including handouts to customers who will not receive bills before that date.