A taste and odor expert may have determined the source of last month’s foul-smelling water in Orange County.
According to the Virginia Department of Health, a submerged water pump experienced a “catastrophic” failure on Aug. 20 at the Wilderness Water Treatment Plant, releasing “food-grade” mineral oil into water at the treatment plant. The pump showed signs of overheating.
Other pumps failed at Wilderness on Aug. 24 — the same day VDH’s Do Not Use advisory was loosened to a Do Not Drink advisory. These were in intake wells that pull water from the Rapidan River, which were shut off from the system and left stagnant.
The pump distributor told VDH that the failure was likely due to electrical issues: The pump was higher horsepower than its predecessor, but the plant’s electrical system wasn’t upgraded to reflect that.
Tim Clemons, Rapidan Service Authority’s general manager, told VPM News a cause for the failure was still being investigated, and that the pump was less than two years old.
Components of mineral oils were discovered in water samples from the stagnant wells earlier this month — and now, an expert in Texas has matched those samples to the same mineral oil used in the Wilderness plant’s pumps.
J. Hunter Adams received a sample of the oil last week. He simulated the conditions the oil was under in the overheating pumps and determined the odor heated mineral oil produced was “identical” to the WD-40–like scent found in water samples from the treatment plant.
Samples from the stagnant wells also contained hydrocarbons, chemicals derived from petroleum. It was not immediately clear which hydrocarbons were identified, and that class of compound can have wide-ranging health effects — including nerve disorders, dizziness and eye irritation.
According to VDH’s incident website, “The taste and odor expert had a high level of confidence that the odor event was directly related to the mineral oil release on August 20.”
The isolated intake wells have been emptied by a contractor and cleaned by RSA.
The petroleum-like odor was first reported on Aug. 21 by residents in eastern Orange County, prompting a Do Not Use advisory from the Rapidan Service Authority and the Virginia Department of Health that day: No drinking, no cooking, no washing and no cleaning with tap water. (Flushing was permitted.)
It impacted roughly 13,000 people, closing schools and businesses in that part of the county. On Aug. 23, a VDH epidemiologist interviewed five affected families that reported illness after the contamination was detected. The health agency hasn’t provided a public update on that investigation.
The advisory was later downgraded to a Do Not Drink before being fully lifted Aug. 27, when the odor had dissipated from the treatment plant. At the time, VDH and Rapidan Service Authority stated that several rounds of testing had been conducted to ensure the treated water was safe for consumption: “In every case, the test results came back showing that the water met federal and state standards for drinking water.”
Clemons said RSA stopped receiving calls about the odor in early September.
VDH’s Office of Drinking Water did not respond to a request for comment by publication.
