Greensboro published a ‘year one’ report on its 1,4-Dioxane chemical discharges. Here’s what you need to know.


The city of Greensboro published a Special Order by Consent Year One report in June, coming in the wake of yet another accidental discharge of 1,4 Dioxane — the third since June 2021 — into the Haw River, Pittsboro’s drinking water source.

The 34-page document, spanning May 1, 2021, to April 30, 2022, contains summaries of the city’s investigation results, oversight activities and a public education outreach plan. Here are the highlights:

What is an SOC, and why is it being used?

• In the context of wastewater contamination, a Special Order by Consent (SOC) lays out corrective actions that a person or facility who has accepted responsibility for causing or contributing to water pollution must adhere to, according to the North Carolina Administrative Code used by the N.C. Dept. of Environmental Quality’s Division of Water Resources.

• In November 2019, the city of Greensboro applied for a SOC, an agreement between the city and the DEQ. That month, the DEQ issued a notice of violations and an intent to assess fines against the city for a discharge of 1,4-Dioxane that occurred in August 2019.

• Several municipalities pull drinking water from the Haw River; the town of Pittsboro is the first drinking water utility downstream that does so.

• The original SOC went into effect in May 2021, as did a sampling plan.

• An FAQ document by the Division of Water Resources states: “The purpose of the City of Greensboro’s SOC is to reduce concentrations of 1,4-Dioxane being discharged into the receiving stream in order to protect drinking water sources downstream of the T.Z. Osborne WWTP effluent discharge. This will be done by ensuring the drinking water standard of 35 µg/L is met at the point of the drinking water intakes.”

The city previously developed a 1,4-Dioxane source identification and reduction plan in 2015, after DEQ sampling from the same year pointed to elevated levels of the chemical in South Buffalo Creek.

• Since December 2017, the DEQ has required Greensboro to conduct and report monthly wastewater sampling at the T. Z. Osborne Water Reclamation Facility — the city’s sole wastewater treatment plant.

• The three-year SOC between Greensboro and the DEQ was amended in December 2021, and includes “a comprehensive source study, a public awareness program, continued collaboration/oversight of indirect sources of 1,4-Dioxane, TZO effluent compliance values, annual reports, and civil penalties for noncompliance with SOC requirements.”

What is 1,4-Dioxane?

• 1,4-Dioxane is a chemical and flammable liquid classified as a likely human carcinogen by the EPA. The chemical, which is completely mixable in water, has been found at federal facilities and in groundwater, owing to its common use as a stabilizer in some paint strippers, greases and chlorinated solvents, according to an EPA technical fact sheet.

What’s happened in Year One and what’s next?

• The city of Greensboro and DEQ held four quarterly meetings between May 2021 and February 2022 regarding the SOC.

• In the first year of the SOC, the report states that Greensboro gathered more than 900 samples, incurring commercial laboratory testing costs of over $120,000.

• There were three compliance value exceedances in the past year, when T.Z. Osborne’s effluent 1,4-dioxane concentration is greater than 45 µg/1.

According to the report, a compliance value exceedance that occurred in June 2021 — and for which the source couldn’t be detected — led the city to re-evaluate the initial focus of the SOC sampling. As a result, Greensboro received a penalty demand letter and was required to pay a $1,000 penalty in November 2021.

In November 2021, another compliance value exceedance occurred. After further sampling, the city believed the Patton trunkline in southern Greensboro, which feeds the wastewater treatment plant, to be the probable source of the high discharge of 1,4-Dioxane, though staff couldn’t determine the specific industry. The city then held mandatory meetings with SIUs on the Patton trunkline; Greensboro received a penalty demand letter and paid a $1,000 penalty in February 2022.

For a third time, in April 2022, the city detected another compliance value exceedance, again believed to be attributed to the Patton trunkline after additional sampling. Five industries — Ecolab, Elastic Fabrics, Lanxess, Precision Fabrics and Vertellus — on the Patton trunkline were required to send weekly composite samples for rush analysis, according to the report. Results from Lanxess likely indicated they were the source, with their weekly composite being 15,200 µg/l. Manufacturing of the suspected products has stopped for the time being at Lanxess’s Greensboro facility. Lanxess is a specialty chemicals company, and the Greensboro location functions as a production site for the company’s Polymer Additives Business Unit. Again, due to the exceedance, the city received a penalty demand letter and was assessed a stipulated penalty of $1,000.

• Greensboro identified nine significant industrial users, or SIUs, in Year One that had discharge concentrations higher than 100 µg/l, and facility inspection of the SIUs increased from once to three times a year.

Year Two and Three

• According to the report, for the second and third years of the SOC, one priority will be a focus on educating the public on risks associated with 1,4-Dioxane, as well as products that contain the chemical, through means such as a public awareness campaign and public service announcements.

• Greensboro is also planning to develop a water bill insert with relevant information on 1,4-Dioxane that will encourage customers to view the city’s website for more details.

The full report can be accessed on the City of Greensboro’s website at

Reporter Maydha Devarajan can be reached at and on Twitter @maydhadevarajan.

Haw River, Pittsboro, Greensboro, water, contamination, 1, 4 Dioxane


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