The Pulse

Greensboro official: “No trigger level” at which we were required to alert DEQ of high 1,4-Dioxane levels

By: - October 21, 2019 1:41 pm
Simple, but toxic: A chemical model of 1,4 dioxane, an emerging contaminant and likely carcinogen.

The City of Greensboro didn’t immediately report an alarming spike in levels of 1,4-Dioxane in its wastewater to state officials because there was no requirement that it do so, a top utility official said today.

A likely human carcinogen, 1,4-Dioxane was released from Greensboro’s TZ Osborne wastewater treatment plant on Aug. 7. The levels were high enough that it contaminated Pittsboro’s drinking water more than 4o miles downstream. There, concentrations reached 114 ppb, and likely contaminated the water supply for about a week. Although the EPA does not regulate 1,4-Dioxane, it has set a recommended health goal of 0.35 ppb.

Nonetheless, Greensboro officials didn’t disclose the increase until Sept. 27, when its monthly discharge report was due to the NC Department of Environmental Quality.

“Whether the levels were high or low, there was no trigger level” set by DEQ at which Greensboro was required to promptly alert state officials, Mike Borchers, assistant director of Greensboro’s Division of Water Resources, told Policy Watch.

North Carolina Health News first reported the discharge and spike in the 1,4-Dioxane levels in drinking water.

Greensboro has been reporting 1,4-Dioxane concentrations in its wastewater discharge each month since December 2017; as part of a targeted three-month monitoring plan, DEQ had required additional sampling this summer. The sampling and reporting are required as a condition of its federal discharge permit — an NPDES — that is administered by state environmental regulators.

At the end of August, levels of 1,4-Dioxane in the wastewater had decreased to 17.5 ppb, In September, the levels dropped further to 5.98 ppb, but rebounded again on Oct. 15, to 12.5 ppb, Borchers said.

While the decrease is notable, the concentrations are still far above the EPA’s health goal.

Greensboro is now required to submit weekly samples to DEQ. An agency spokeswoman said DEQ’s lab is still analyzing the first set of samples, which were received last week.

The discharge originated at Shamrock Environmental in Browns Summit. The facility contracts with other industries throughout the Southeast for oil recycling, hazardous and non-hazardous waste hauling and storage, and decontamination and vacuum services for trucks. In a press release, Shamrock Environmental said its facility, which is located in an industrial park across from the NC Soccer Complex, discharged 15,825 gallons of “non-hazardous wastewater” originating from a customer that did not report the material contained 1,4-Dioxane.

Shamrock Environmental last week declined to name the customer to Policy Watch.

“They won’t tell us, either,” Borchers said, adding that the company has been “supportive in trying to come up with a management strategy, and how we make the screening process better.”

The sources of the contaminant are industries and wastewater treatment plants upstream. Burlington, Greensboro, Asheboro and Reidsville receive the contaminated discharge, and since 1,4-Dioxane can’t be removed from either water or wastewater using traditional treatment methods, the plants  in turn, send that contaminated effluent into the Haw River, its tributaries and through the taps of Pittsboro water customers.

The upstream pollution sources have not always been cooperative in taking responsibility. According to a timeline posted on the Town of Pittsboro website, in early 2017, well after NC State University scientist Detlef Knappe had released his findings, Kevin Eason, then with Reidsville’s Public Works Director, called Knappe “an outlier” during a phone call to Pittsboro officials.

Easton then reportedly said that Reidsville Mayor Jay Donecker “was a scientist.” Donecker is a veterinarian.

Easton also blamed fracking in Stokes County for the contamination downstream. However, no fracking occurred in Stokes County; the NC Geological Survey contracted with a firm to only drill test holes.

As a result of the contamination, the Town of Pittsboro has been struggling to cap levels of 1,4-Dioxane in its drinking water since at least 2014, when  Knappe began studying the presence of the compound in the Haw River. Pittsboro has been using granulated activated charcoal to reduce the contamination in its drinking water, but the town is still searching for a long-term solution.

In late August of this year, CDM Smith, a consulting firm, presented town officials with cost estimates for various advanced treatments — reverse osmosis, ion exchange, granulated activated charcoal and ultra-violet light/advanced oxidation.

Costs ranged from $9 million to $27 million for treatment alone, plus an estimated $20 million to $69 million to expand the plant or seek other water supplies in order to meet projected increases in the number of customers.

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Lisa Sorg
Lisa Sorg

Assistant Editor and Environmental Reporter Lisa Sorg helps manage newsroom operations while covering the environment, climate change, agriculture and energy.