The Pulse

Sanford’s wastewater treatment plant legally discharges high levels of PFAS. Public can chime in on whether to strengthen its permit.

By: - March 6, 2023 2:07 pm

In an area already burdened by toxic chemicals in their drinking water, residents, environmental advocates and public water systems are asking state regulators to strengthen requirements for Sanford’s wastewater treatment plant – especially for discharges of toxic PFAS and 1,4-Dioxane. 

The City of Sanford has applied to the NC Department of Environmental Quality to renew its discharge permit for the Big Buffalo wastewater treatment plant on Iron Furnace Road. The facility sends as much as 12 million gallons of wastewater each day into the Deep River, part of the Cape Fear River Basin. 

In turn, the Deep flows into the Haw and eventually the Cape Fear rivers – the drinking water supply for more than a million people, from Reidsville to Fayetteville to Wilmington.

These waterways already contain PFAS and 1,4-Dioxane from multiple sources, including Greensboro, Burlington, Asheboro and Reidsville utilities – and Sanford itself.


Public hearing on Sanford’s wastewater permit
Tuesday, March 7, 6pm,
McSwain Extension Education and Agricultural Center
2420 Tramway Road, Sanford

1,4-Dioxane is a known carcinogen. PFAs have also been linked to cancer, as well as thyroid disorders, low birth weight, reproductive disorders and other serious health problems. These are known as “forever chemicals” because they don’t break down in the environment, where they can remain for hundreds of years.

What happens in Sanford could affect thousands of people in the Cape Fear River Basin. The city has ambitious plans to sell its water and wastewater treatment services to neighboring towns, such as Fuquay-Varina, Holly Springs and Pittsboro, as well as the proposed VinFast battery plant near Moncure, in Chatham County. 

“The quality of the wastewater and the functioning of Sanford’s pretreatment system has a direct bearing on the quality of drinking water that Sanford provides to its growing customer base,” wrote Mick Noland, interim CEO and general manager of the Fayetteville Public Works Commission, to DEQ. 

The Fayetteville utility has struggled to remove these contaminants from its drinking water because of discharges upstream.

A major challenge for Sanford is that its wastewater treatment plant lies 15 miles upstream of its drinking water intake, akin to building an outhouse (whose waste has been treated, of course), uphill of a private well. 

In 2020, Sanford reported total PFAS in its wastewater discharge ranging from 62.17 parts per trillion to 399.43 ppt, far above the EPA’s health advisory goals. The discharge contained two particularly harmful PFAS compounds, PFOA and PFOS, at concentrations as high as 15.2 ppt — 3,800 times EPA’s health advisory — and 14.3 ppt — 715 times EPA’s health advisory — respectively.

“As staggering as these results are, the full scope of the pollution is likely even greater …” wrote the Southern Environmental Law Center in its comments to DEQ. “Indeed, studies have found, there can be a ‘substantial increase’ in specific PFAS after treatment.” This increase can occur when precursors – compounds that degrade into PFAS – form as a result of chemical reactions.

The toxic compounds persist in the drinking water through a continuous loop of contamination. Because traditional wastewater treatment methods can’t remove the compounds, contaminated discharge pollutes the drinking water supply. And then when homes, businesses and industry pour drinking water down the sink, or run the shower or washing machine, the contamination cycles back to the wastewater treatment plant. 

Public comments submitted to DEQ so far have asked for weekly monitoring of PFAS and 1,4-Dioxane, in discharge leaving the plant, rather than quarterly or monthly. 

In particular, 1,4-Dioxane discharges often occur in “slugs” – an unexpected mass of the compound – that then heads downstream. That has happened several times in Greensboro, which resulted in high levels of 1,4-Dioxane in Pittsboro’s and Fayetteville’s drinking water.

More frequent monitoring, wrote Noland, would give Sanford more opportunity to notify downstream utilities if a slug of 1,4-Dioxane were headed their way.

Yet as drafted, the permit doesn’t have “numeric” limits on PFAS and 1,4-Dioxane. Instead, DEQ proposes only to require Sanford to monitor for the compounds and report them to the agency. In the case of 1,4-Dioxane, DEQ does have the option to reopen the permit and impose stricter limits.

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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.