DANVILLE (WSLS 10) - After months of trying to figure out what is causing its water to smell and taste strange, Danville announced it will boost the amount of carbon being added to the system.
Danville began adding activated carbon to the water after issues with an "earthy odor and taste" started in February, 2015. Tests of raw water samples from the Dan River confirmed the presence of three species of algae associated with odor and taste, including a high concentration of Synura. The problem re-emerged in March.
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The Virginia Department of Environmental Quality was unable to confirm the presence of algal blooms, but those results were limited to the samples collected on a particular day, and the Virginia Department of Health's Office of Drinking Water said remained confident that biological activity was the culprit.
The city said water was and continues to be safe to use and drink. The treatment plant's filtration system removes both algae and carbon particles before the water enters the distribution system.
The Office of Drinking Water said algae are naturally present in all surface waters and excessive growths into blooms can cause taste and odor problems. It said carbon is the best solution to remove unpleasant odor and taste caused by biological activity.
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Throughout both odor and taste events, the Office of Drinking Water said the water in the city's system went through all of the treatment processes and confirmed all tests showed Danville's drinking water met state and federal regulations.
The city has notified both the Office of Drinking Water and the Virginia Department of Environmental Quality (DEQ) of the slight elevation in odor in the raw water samples collected this morning.
A DEQ environmental monitoring team said it will collect additional samples Thursday along the Dan River. The team's river run had been previously scheduled as part of the agency's ongoing monitoring efforts.
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In addition to collecting water samples along the Dan River, the city said it requested the agency collect samples along the Smith River. Danville said the city has received more reports of an odd odor from people who live along the Smith River near Martinsville. The Smith River is a tributary to the Dan River.