The City of Greensboro says that years of monitoring, enforcement and cooperation with local industries have led to a 97 percent reduction in levels of 1,4-dioxane – an unregulated, emerging contaminant – in wastewater discharged into the local environment.

According to a city press release, Greensboro’s Water Resources Department has reduced concentrations of 1,4-dioxane in effluent from the T.Z. Osborne Wastewater Treatment Plant by 97 percent since 2015.

City officials say that Greensboro was the first municipality in North Carolina to proactively identify sources of the chemical and launch a monitoring and minimization program – rather than waiting for formal state or federal regulation.

The city doesn’t manufacture or intentionally use 1,4-dioxane. Instead, officials say it typically enters the wastewater system as an unintended pass-through from industries that are connected to the sewer system.

Through the city’s Industrial Pretreatment Program, Greensboro has worked directly with those industries to identify sources, improve processes and significantly reduce discharges.

City officials say that the remaining trace levels now detected are largely associated with consumer household products that aren’t currently regulated.

According to information posted on the city’s website, 1,4-dioxane is a synthetic chemical that can be found as a by-product in items such as paint strippers, dyes, greases, antifreeze, aircraft deicing fluids and some consumer products. It can also occur unintentionally during the manufacturing or recycling of certain plastic and polyester products.

Since 2014, the compound has been a growing concern among municipal wastewater dischargers and the North Carolina Department of Environmental Quality.

Prior to that time, 1,4-dioxane wasn’t regulated in treated waste, and many industries didn’t test for or monitor it.

In 2021, the City of Greensboro and the North Carolina Department of Environmental Quality completed negotiations on a Special Order by Consent addressing elevated levels of 1,4-dioxane discharged from the T.Z. Osborne plant into South Buffalo Creek.

The stated purpose of the agreement was to reduce concentrations of the compound released from that facility.

Water Resources Director Mike Borchers said the city chose early action over delay as scientific guidance on emerging contaminants continues to evolve.

“Our goal is simple,” Borchers said. “We are committed to being proactive, transparent, and responsible stewards of our water resources. When new challenges and concerns arise, we act quickly to protect public health and the environment.”

City officials say that Greensboro continues to work closely with NCDEQ and downstream communities, while investing in advanced monitoring and ongoing collaboration with industry partners.

Sampling results related to 1,4-dioxane are posted on the city’s website, along with information for residents about products that may contain the compound and ways to reduce household exposure.

Greensboro officials say that the city’s approach is intended to keep Greensboro ahead of future water quality standards while protecting public health and the region’s waterways for the long term.

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