A municipal drinking water plant. Unlike at a private well, water is treated for bactria and for chemicals such as 1.4 dioxane at a central location, then pumped through pipes to residents. This can symbolize 1,4 dioxane contamination and clean water.
A municipal drinking water plant. Unlike at a private well, water is treated at a central location, then pumped through pipes to residents. Photo courtesy Wikimedia Commons

By Greg Barnes

For nearly two years, state regulators have required Greensboro and Reidsville to monitor monthly for the probable carcinogen 1,4 dioxane at their wastewater treatment plants.

The data, which the state never made public before Friday, show alarmingly high concentrations of the chemical being released repeatedly into the Haw River from December 2017 until September 2019.

The monitoring reports for Reidsville show that 20 of 27 monthly samples exceeded the federal health advisory for the chemical in drinking water.

At Greensboro’s treatment plant, eight of 27 samples exceeded that standard.

All of the samples taken at both treatment plants exceeded the state’s health advisory for surface waters used for human consumption.

Last week, the DEQ issued notices of violation to Greensboro and Reidsville, accusing them of violating their wastewater pretreatment permits. The cities could now each face fines of up to $25,000.

Specifically, the DEQ said Greensboro failed to call the DEQ about an Aug. 7 release of 1,4 dioxane “as soon as possible” and no more than 24 hours from the time of detection, as required under the permit.

Reidsville received an almost identical notice of violation for a release that was reported to have happened on June 12.

‘Very alarming’ levels

The DEQ has been trying since 2014 to get industries to stop discharging 1,4 dioxane into the Cape Fear River basin. Requiring the monthly testing is just one example of those efforts.

But this is the first time the DEQ has issued notices of violation against either city, despite data appearing to show that they have violated permit requirements multiple times, potentially endangering the health of thousands of people living downstream.

1,4 dioxane by numbers:

  • 35 parts per billion: federal 1,4 dioxane health advisory level
  • 0.35 parts per billion: NC 1,4 dioxane health advisory level

From Dec 2017 (when DEQ started to ask for monthly levels) – Sept 2019:

  • Lowest 1,4 dioxane release detected in Greensboro: 6 ppb
  • Highest 1,4 dioxane release detected in Greensboro: 957.5 ppb
  • Lowest 1,4 dioxane release detected in Reidsville: 4.54 ppb
  • Highest 1,4 dioxane release detected in Reidsville: 372 ppb

One release of 1,4 dioxane, found in an Aug. 7 sample in Greensboro, caused a temporary spike of the contaminant downstream in Pittsboro’s drinking water that measured 107 parts per billion. That’s more than three times the U.S. Environmental Protection Agency’s health advisory for drinking water and more than 300 times the North Carolina standard for surface waters used for drinking.

At a forum last month in Chatham County, N.C. State researcher Detlef Knappe said the  release probably stayed in the pipes of Pittsboro residents’ homes for about a week. Knappe called the levels “very alarming” and encouraged people to buy reverse osmosis filtration devices.

shows the map of the River basins in north central North Carolina, where there have been numerous releases of 1,4 dioxane of late
The town of Reidsville straddles two river basins, the Dan/ Roanoke River basin to the north and the Cape Fear River basin to the south. Little Troublesome Creek, has two branchheads which both emerge within the town limits and then merge to flow south, eventually emptying into the Haw River. Map courtesy: NC DEQ

In mid-October, NC Health News learned about the release and published a story about it. The next day, the DEQ announced that it would investigate Greensboro and Reidsville for possible permit violations. It also revealed the name of the Greensboro company responsible for the discharge, Shamrock Environmental Corp., after Greensboro officials refused to do so. NC Health News had been asking the city to name responsible companies since 2016.

Sharon Martin, a DEQ spokeswoman, said the DEQ decided to issue the notices of violation against Greensboro and Reidsville after the elevated levels of 1,4 dioxane were found in Pittsboro’s drinking water.

Staggering levels of contamination

The U.S. Environmental Protection Agency has not set a maximum contaminant level for 1,4 dioxane, but it has established a health advisory of 35 parts per billion in drinking water. The EPA says a person who consumes that level of 1,4 dioxane over a lifetime stands a 1 in 10,000 chance of getting cancer.

North Carolina has a health advisory of 0.35 parts per billion of 1,4 dioxane in surface waters used for human consumption. A person who consumes that level of the contaminant over a lifetime stands a 1 in 1 million risk of getting cancer.

Animals exposed to large concentrations of 1,4 dioxane in laboratory studies have suffered liver and kidney damage, as well as cancer.

The wastewater treatment plants for Greensboro and Reidsville discharge their treated effluent into the Haw River, which flows into Jordan Lake. From there, the water flows into the Cape Fear River, where hundreds of thousands of people get their drinking water.

Utilities cannot easily or inexpensively filter 1,4 dioxane out of their drinking water. Pittsboro, the only municipality on the Haw River to draw its drinking water from the Haw River, is considering a new filtration system that can remove the contaminant.

Ample concern for Pittsboro

According to the DEQ data, all monthly samples taken at the Greensboro and Reidsville wastewater treatment plants between December 2017 and September 2019 exceeded the state’s health advisory for surface waters.

The data show that the highest level of 1,4 dioxane recorded in Greensboro was the Aug. 7 release of 957.5 parts per billion, which is more than 27 times higher than the EPA’s health advisory for drinking water.

Seven other releases were detected above the EPA’s health advisory at the Greensboro plant, including levels of 397.5 parts per billion in April 2019; 408 parts per billion in August 2018; and 665 and 229 parts per billion in May 2018.

The data for Reidsville show the highest releases this year of 367 parts per billion on June 12; 280 parts per billion on Feb. 6; and 273 parts per billion on Jan. 9. Last year, Reidsville recorded releases of 372 parts per billion on Oct. 5; 368 parts per billion on May 7 and 701 parts per billion on Jan. 29.

Understanding parts per million, billion and trillion

Keeping track of such small quantities can be tricky.

  • A part per million is like diluting four drops of ink into a 55-gallon drum of water.
  • A part per billion is like diluting two drops of ink into a large gasoline tanker truck filled with water.
  • A part per trillion is like diluting less than half a drop of ink into an Olympic-sized swimming pool.

The biggest discharge recorded in Reidsville occurred on Oct. 11, when 1,4 dioxane measuring 1,400 parts per billion was detected at the treatment plant. That is 40 times higher than the EPA’s health advisory for drinking water.

After learning of that release, the DEQ almost immediately began notifying downstream water utilities, something it did not do after learning about the Aug. 7 release in Greensboro. Officials with the DEQ said the earlier Greensboro discharge had dissipated by the time they learned about it.

Making the data known

Although the DEQ had been requiring Greensboro and Reidsville to monitor for 1,4 dioxane for nearly two years, it never made anyone aware of those findings.

Martin, the DEQ spokeswoman, said the department made the data public for the first time Friday, at the same time it announced the notice of violations.

Martin called the notices “a single step in a much larger, ongoing effort to bring the pretreatment plants and their customers into compliance and determine other contributing sources of 1,4 dioxane in the river basin.”

Mick Nolan, chief operations officer for the Fayetteville Public Works Commission’s Water Resources Division, said he was never made aware of the pollution data until now, either.

shows a map of the Cape Fear River basin witih landmarks noted, including Fayetteville, where GenX and 1,4 dioxane entered the river
This map shows the length of the Cape Fear River basin. Source: National Oceangraphic and Atmospheric Administration.

Nolan said he and representatives of other water utilities have been meeting almost quarterly for more than a year with state regulators, officials from Greensboro, Reidsville and Asheboro, and others to explore ways to stop industries from polluting rivers and streams.

“I’m encouraged that, even though it should have been done sooner, the state is taking enforcement action against these cities,” Nolan said.

Emily Sutton, the Haw River riverkeeper, said she is also encouraged by the DEQ’s action because it finally begins to hold polluters accountable for their permit violations.

“However, the releases of 1,4 dioxane expose a broader ongoing problem in the Haw River watershed and across the state that needs to be addressed,” Sutton said in a statement. “DEQ should be setting limits for wastewater treatment operations that are protective of human health and keep toxic industrial compounds out of our surface waters and drinking water supplies. DEQ should also be requiring dischargers to disclose what is in their waste, as mandated by the Clean Water Act, and moving to control other substances known to harm public health. ”

Taking action

The DEQ’s Division of Water resources has been sampling for 1,4 dioxane in the Cape Fear River basin since 2014, after municipalities began reporting elevated levels of the contaminant during required sampling by the EPA.

The state’s monitoring revealed the probable carcinogen downstream of the Greensboro, Reidsville, and Asheboro wastewater treatment plants, all of which eventually discharge into the Cape Fear River. Since then, the division has collaborated with those cities to reduce the discharges, the DEQ says. All three cities were required to submit corrective action plans.

Martin said the requirement for the cities to monitor monthly for 1,4 dioxane stemmed the DEQ’s “larger management strategy to assess and determine the extent of the 1,4 dioxane issue and the effectiveness of reduction efforts at the pretreatment programs.”

The DEQ has also required 25 municipalities with pretreatment programs in the Cape Fear River basin to sample for 1,4 dioxane and perfluorinated chemicals, known as PFAS. Results of the sampling, from July through September, are not ready to be disclosed, Martin said.

Industries primarily use 1,4 dioxane as a solvent stabilizer to make other chemicals. It can be found as a byproduct in some cosmetics, detergents and shampoos, and in paints, varnishes and adhesives. It is often used in the textile and plastics-recycling industries.

Chuck Smith, director of Reidsville’s Public Works Department, and Mike Borchers, a director with Greensboro Water Resources, said they have been working with the DEQ for years in an effort to reduce contamination leaving their wastewater treatment plants.

Smith said Reidsville had encouraged the DEQ to provide the city with information on how to regulate 1,4 dioxane, which he said was not listed as a violation until recently.

“Until either of those occurred, the City could not take action regarding the matter under State requirements and required actions,” Smith said in an email to NC Health News. “The City of Reidsville has been working with NC DEQ and our sources of 1, 4 dioxane to jointly pursue strategies that will reduce the amounts, but the research into 1,4 dioxane is not at the level that other substances that are regulated by both the Federal and State level.”

Smith also said there seems to be confusion among state and federal officials about the regulation of 1,4 dioxane and other substances. He said that years ago, Reidsville submitted data for a new federal pollution permit issued through the DEQ, which has never been issued. The city continues to operate under a permit that expired in 2016 and does not have a limit for 1,4 dioxane, Smith said.

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Greg Barnes retired in 2018 from The Fayetteville Observer, where he worked as senior reporter, editor, columnist and reporter for more than 30 years. Contact him at: gregbarnes401 at gmail.com