People who rely on the town of Pittsboro for their drinking water were likely exposed to high levels of 1,4-Dioxane for about a week in August, after the City of Greensboro discharged the compound, a likely carcinogen, into a tributary of the Haw River.
Levels of 1,4-Dioxane spiked to 114 parts per billion in the town’s drinking water in August, shortly after the discharge. Although the EPA doesn’t regulate 1,4-Dioxane, it has established a lifetime health goal of 0.35 ppb. At the drinking water forum sponsored by the Haw River Assembly in Pittsboro last night, NC State University scientist Detlef Knappe called the concentrations “very alarming.”
He estimated people were exposed to these levels for about six days before the contaminated water traveled through the town’s system.
North Carolina Health News first reported the discharge and spike in the 1,4-Dioxane levels in drinking water.
But many questions remain about who knew what and when — and the answers have not been forthcoming.
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, located in an industrial park, discharged 15,825 gallons of “non-hazardous wastewater” originating from a customer that did not report the material contained 1,4-Dioxane, a likely human carcinogen. The discharge occurred on Aug. 7.
Monty Hagler, spokesman for Shamrock Environmental declined to name the customer to Policy Watch.
The wastewater then entered the TZ Osborne Wastewater Treatment Plant in Greensboro, which in turn discharged it into South Buffalo Creek, a tributary of the Haw River. 1,4-Dioxane then contaminated the Haw River, the drinking water supplies for thousands of people living downstream.
However, the City of Greensboro did not inform state environmental officials of the discharge until Sept. 27. That’s when the city submitted its monthly discharge report for August, and mentioned it to DEQ staff. DEQ did not announce the discharge until mid-October. Neither DEQ nor Greensboro would name Shamrock as the source of the contamination until North Carolina Health News reported their refusal.
City officials reportedly told DEQ that they were unclear when or if they needed to report the discharge because 1,4 dioxane is an emerging contaminant and does not have a specific permit condition.
It’s unclear why Greensboro officials were unaware of the reporting requirements; a city spokeswoman could not be reached by phone or email for clarification.
In fact, a press release from the city says that since 2015 Greensboro “has been proactive in working with NCDEQ and the industry” to reduce the discharge of 1,4-Dioxane “to the maximum extent practicable” — about 80 percent. The city also noted that it had identified Shamrock Environmental in Browns Summit as a “significant source” of the compound as early as 2015.
And, according to DEQ documents online, the TZ Osborne plant had been monitoring its 1,4-Dioxane discharge since December 2017. DEQ also sampled sites in the Cape Fear River Basin in 2018 and posted the results online.
Then in April of this year DEQ sent letters to treatment plants and industrial dischargers throughout the Cape Fear River Basin about a three-month investigative monitoring program to begin in July. The letter specifically mentioned 1,4-Dioxane.
On July 22, 2019, DEQ requested the plant provide a plan to reduce the amount of the compound leaving the plant. That plan was due Sept. 23.
According to online records, Shamrock Environmental has not been cited for violations in North Carolina, although the database is not comprehensive. But the Ohio Environmental Protection Agency did issue a Notice of Violation to the company in March 2016 for failing to obtain a proper hazardous waste manifest.
1,4-Dioxane has long been a contaminant of concern in the entire Cape Fear River Basin. In 2014, DEQ began a monitoring program from Reidsville to Wilmington, including the Haw River, the Cape Fear and several tributaries.
That monitoring showed levels as high as 1,030 ppb near Reidsville and 543 ppb near McLeansville.
Previous monitoring of Pittsboro’s drinking water showed varying levels of 1,4-Dioxane:
- 15.6 ppb in 2014
- 17.1 ppb in 2015
- 7.5 ppb in 2016
A second monitoring period ran over 18 months from 2017 to 2018. That sampling showed levels of 1,4-Dioxane at 35 ppb in the Haw River near Pittsboro on May 9, 2018.
On June 13, 2018, the compound was found at 11 ppb in the upper arm of Jordan Lake, where the Haw enters the reservoir. Jordan Lake is the drinking water supply for hundreds of thousands of people, including those living in Chatham and Wake counties.
Julie Grzyb, a permit writer in the Division of Water Resources, told attendees at a public forum in Pittsboro last night that the state could pursue enforcement action against the city. Even though Shamrock was the discharger, Greensboro is held responsible because it holds the discharge permit. DEQ could also enter into a Special Order by Consent with Greensboro, a legal document that lays out requirements for facilities that are “unable to consistently comply with the terms, conditions, or limitations” in their discharge permits.