Levels of 1,4-Dioxane above health advisory goal in untreated drinking water in Pittsboro

One sample of raw — or untreated — drinking water in Pittsboro contained levels of 1,4-Dioxane above the health advisory goal, and concentrations in treated water continue to rise, according to test results released late this afternoon by the town.

On Nov. 16, a sample of raw water contained 38.1 parts per billion of 1,4-Dioxane, a likely carcinogen. The EPA’s and the state’s health advisory goal is 35 ppb; that’s equivalent to a 1-in-10,000 excess cancer risk over a lifetime of exposure. That goal is not as protective as the surface water goal of 0.35 ppb, which represents a 1-in-1 million excess cancer risk.

Finished drinking water at the town’s treatment plant rose from 16.8 ppb to 21.3 ppb over just one day: Nov. 15-16. However, the town can instead use water in storage tanks, which have much lower concentrations, between 1 ppb to 4.6 ppb.

“Town staff remains concerned by the increase in 1,4-Dioxane levels seen in raw water samples,” Town Manager Chris Kennedy said in a press release, “and will continue to exert our energies toward manipulating our water operations in an effort to reduce the concentration levels in our water distribution lines.

The source of the 1,4-Dioxane is Greensboro’s TZ Osborne wastewater treatment plant, which on Nov. 3 illegally discharged high amounts of the compound — 767 ppb — into a tributary of the Haw River. The river serves as Pittsboro’s drinking water supply.

The ultimate source of the 1,4-Dioxane is likely an industrial customer of Greensboro’s. The city has not publicly announced the responsible industry.

The EPA has yet to regulate 1,4-Dioxane in drinking water.

On Nov. 8 and 9, town officials found low levels of 1,4-Dioxane in the water supply and believed the slug of the compound had passed the raw water intake during a time of low demand.

But dry weather has slowed the water flow in the Haw, and several residents said at the time that levels in the town’s drinking water supply were low only because the slug had not arrived yet.

That turned out to be true.

When the most recent spill occurred, Greensboro had a goal of just 45 ppb in its discharge, according to a Special Order by Consent between the NC Department of Environmental Quality and the city. That order was the result of a major 1,4-Dioxane spill in 2019; a subsequent spill last year also violated the terms of the order.

The Haw River Assembly and Fayetteville Public Works, whose water supply is also degraded by these releases, legally challenged the order and asked for stronger environmental protections.

Today the Environmental Management Commission approved a settlement agreement that reduces the goal to 35 ppb in the first year, and 23 ppb by the third year of the order.

Greensboro must also sample its industrial sources, publicly post its sampling data and information about its investigation of pollution sources. It further requires Greensboro to sample downstream at Pittsboro’s drinking water intake on the Haw River and in Jordan Lake.

“The agreement puts Greensboro on the path to controlling its 1,4-dioxane pollution and protecting downstream communities, but it isn’t the last word,” said Geoff Gisler, senior attorney at the Southern Environmental Law Center, which represented the Haw River Assembly and the City of Fayetteville. “We’ll monitor the sampling and watershed investigations secured as part of this settlement and ensure polluters are held accountable. We encourage DEQ to go beyond those investigations and act on Greensboro’s pending permit application to impose strict limits on 1,4-dioxane pollution to protect communities downstream over the long-term.”

“Without these legal challenges brought by Haw River Assembly and City of Fayetteville, the original order would have allowed Greensboro to continue polluting the Haw River with higher levels of 1,4-dioxane, and with much lower penalties for extraordinarily high discharges,” said Emily Sutton, the Haw Riverkeeper. “The monitoring required under this agreement will identify the industries responsible for these toxic discharges in Greensboro and put the responsibility of safe and clean water on polluters, instead of the downstream users.”

After thinking it had “dodged a bullet,” Pittsboro reports increase in 1,4-Dioxane in drinking water

The Haw River, as viewed from the Bynum bridge. The river has been contaminated with 1,4-Dioxane; sources include the City of Greensboro, which is upstream. (File photo: Lisa Sorg)

Just days ago, Pittsboro officials said they considered the town “lucky,” thinking a slug of 1,4-Dioxane from the City of Greensboro had bypassed its water intake on the Haw River. But new test results today have prompted town staff to say they are “concerned by the uptick in concentration in in raw water samples.”

Those samples of untreated water from Nov. 12 show levels of the likely carcinogen at 9.8 parts per billion, almost five times the levels in raw water just two days earlier. Treated water, which is sent to homes, contained concentrations of just above 4 ppb.

The EPA has set a health advisory goal of 35 ppb in drinking water, which represents a 1-in-10,000 excess lifetime cancer risk. That is not as protective as the 1-in-1 million cancer risk that the EPA uses for chemicals that have no safe dose; if that standard were applied to 1,4-Dioxane, the maximum amount in drinking water would be 0.35 ppb — far above what Pittsboro is reporting.

However, research is incomplete on 1,4-Dioxane, and the EPA has yet to set legally enforceable standards for the compound.

“While the numbers remain under the EPA advisory level, staff is concerned that sample results may soon eclipse that suggested concentration level” — 35 parts per billion, Town Manager Chris Kennedy said in a press release. “The Town is continuing to draw only the bare minimum of raw water to keep from inundating our system with contaminated water.

Routine sampling showed Greensboro’s TZ Osborne wastewater treatment plant illegally discharged the contamination on Wednesday, Nov. 3, but the city did not receive the lab results until Monday, Nov. 8, at 11:20 a.m.  The amount of 1,4-Dioxane in the original discharge was 767 parts per billion; that’s more than 2,100 times the EPA’s and the state’s health advisory goal for surface water.

Pittsboro officials believed the slug of 1,4-Dioxane had passed its water intake during a time of low demand. However, several residents commented on social media that the slug was merely delayed by low stream flow in the Haw River. Based on today’s results, those concerns appear to be valid.

According to Greensboro data, on Nov. 8, five days after the discharge, samples of the Haw River near Glencoe, showed levels of 1,4-Dioxane at 99 ppb. Glencoe is 35 miles north and upstream of Pittsboro.

On Nov. 10 and 11, Pittsboro reported low levels of 1,4-Dioxane in raw and treated water, but on Nov. 12, a spike occurred, which could coincide with the contamination making its way down the Haw from Glance.

Town staff continues to pull samples for expedited results. The next round is expected within 24 hours.

 

Pittsboro officials: “the Town was simply lucky this time” regarding 1,4-Dioxane from Greensboro

The Haw River, as viewed from the Bynum bridge (File photo: Lisa Sorg)

The slug of toxic 1,4-Dioxane coursing down the Haw River from Greensboro arrived in Pittsboro at just the right time.

Pittsboro Town Manager Chris Kennedy announced in a press release today that based on low levels of compound in drinking water, the contamination passed the town’s water intake from the Haw River during “dormant raw water draw hours,” when demand is low, as common in fall and winter.

Levels of 1,4-Dioxane in both treated and untreated water in Pittsboro ranged from less than 1 part per billion to 2.09 ppb. The EPA has set a health advisory goal of 35 ppb in drinking water, which represents a 1-in-10,000 excess lifetime cancer risk.

That is not as protective as the 1-in-1 million cancer risk that the EPA uses for chemicals that have no safe dose. However, research is incomplete on 1,4-Dioxane, and the EPA has yet to set legally enforceable standards for the compound.

1,4-Dioxane is a toxic chemical used in degreasers that the EPA has classified as a likely carcinogen.

Routine sampling showed Greensboro’s TZ Osborne wastewater treatment plant discharged the contamination on Wednesday, Nov. 3, but the city did not receive the lab results until Monday, Nov. 8, at 11:20 a.m.

Kennedy said that Greensboro notified them about three hours later. The amount of 1,4-Dioxane in the original discharge was 767 parts per billion; that’s more than 2,100 times the EPA’s and the state’s health advisory goal for surface water. That level is more stringent — just 0.35 ppb — than in drinking water.

If Pittsboro’s raw water intake had pulled the contamination into the drinking water system, which has happened before, the contamination would have “persisted in our system for weeks,” Kennedy said. “While this news is a relief, it does not discount the fact that an excessive release could have contaminated our drinking water supply. Frankly, the town was simply lucky this time.”

Kennedy said the town will continue to sample both treated and untreated water “until it is abundantly clear that the 1,4-Dioxane has cleared the raw water intake.”

Greensboro has yet to publicly announce the source of the contamination.

The wastewater treatment plant in Greensboro receives discharges from both residential and industrial customers in Guilford County. From there, the plant treats the discharge before sending it into South Buffalo Creek, which feeds the Haw. However, conventional treatment systems don’t remove 1,4-Dioxane.

The discharge violates the terms of a  Special Order by Consent between DEQ and the City of Greensboro, which set a maximum daily level of 45 parts per billion of 1,4-Dioxane in wastewater. The Haw River Assembly, represented by the Southern Environmental Law Center, has challenged the terms of the order, saying they are not protective enough.

The recent incident was just one of several illegal discharges from the Greensboro plant. In July 2021, sampling results showed that levels from in wastewater ranged from 543 parts per billion to 687 parts per billion. Greensboro officials said they had not identified the source.

In August 2019, Greensboro’s discharge contained levels of 1,4-Dioxane ranging from 705 ppb to 1,210 ppb. The source of the contamination was Shamrock Environmental, an industrial customer that discharges its wastewater to the Osborne plant. That incident prompted DEQ to enter a Special Order by Consent with the city.

While DEQ regulates discharge from cities and towns, the municipalities are responsible for regulating their dischargers and ensuring wastewater is compliant with state and federal law.

According to Greensboro documents obtained under public records law, roughly two dozen companies discharge their wastewater into the city system. Since 2018, the city has issued 18 violations related to contaminants in the discharge, none of them related to 1,4-Dioxane.

Shamrock Environmental has been cited three times and fined $2,500 for exceedances of a compound called p-cresol, which is used in the manufacture of household products. Shamrock is not a manufacturer, but is a hauler and disposal service for that sector. Vertellus, a specialty chemical company received violations for exceedances of chloroform, toluene and since.

Greensboro releases yet another slug of 1,4-Dioxane into Haw River, Pittsboro’s drinking water supply

Update Nov. 10, 9:30 a.m.: Cory Saulsbury, superintendent of Pittsboro’s water plant told Policy Watch that sampling from from Nov. 3 to Nov. 8 showed levels of 1, 4-Dioxane at 1.07 ppb. Saulsbury said the town will “continue to monitor the situation by pulling samples every day this week with a rush order.” 

Greensboro’s wastewater treatment plant illegally discharged high levels of the likely carcinogen 1,4-Dioxane into the Haw River, the drinking water supply for the Town of Pittsboro and other downstream communities along the Cape Fear River.

Adam Pickett, Pittsboro’s public utilities director, confirmed to Policy Watch that there had been a discharge. Emails obtained by Policy Watch show that the discharge occurred on Nov. 3, and Greensboro notified downstream communities, including Pittsboro, on Nov. 8. The amount of 1,4-Dioxane in the original discharge was 767 parts per billion; that’s more than 2,100 times the EPA’s and the state’s health advisory goal for surface water.

The discharge violates the terms of a  Special Order by Consent between DEQ and the City of Greensboro, which set a maximum daily level of 45 parts per billion of 1,4-Dioxane in wastewater. The Haw River Assembly, represented by the Southern Environmental Law Center, has challenged the terms of the order, saying they are not protective enough. Haw Riverkeeper Emily Sutton told Policy Watch that Greensboro had not contacted the group directly about the latest discharge, “even as negotiations are underway regarding the Special Order by Consent triggered by major 1,4- dioxane releases” that occurred in 2019 and 2021.

1,4-Dioxane is a toxic chemical used in degreasers that the EPA has classified as a likely carcinogen. There is no regulatory standard for 1,4-Dioxane, but the EPA has set a health advisory goal of 35 parts per billion for drinking water, which equals a 1-in-10,000 lifetime excess cancer risk. The surface water goal is more stringent, at 0.35 ppb, a 1-in-1 million lifetime excess cancer risk.

Emails show that Pittsboro’s latest sampling through Nov. 2 showed levels of 4 parts per billion. It’s still unknown how much 1,4-Dioxane entered the town’s drinking water, but results should be available this afternoon.

Elijah Williams, water reclamation manager for the City of Greensboro, told Policy Watch that utilities staff has notified the NC Department of Environmental Quality (NCDEQ) and downstream utilities and is actively investigating possible sources of the substance.

This is just one of several illegal discharges from the Greensboro plant. The most recent one occurred in July 2021; sampling results showed that levels from in wastewater ranged from 543 parts per billion to 687 parts per billion. Greensboro officials said they had not identified the source.

In August 2019, Greensboro’s discharge contained levels of 1,4-Dioxane ranging from 705 ppb to 1,210 ppb. The source of the contamination was Shamrock Environmental, an industrial customer that discharges its wastewater to the Osborne plant.

The TZ Osborne Wastewater Treatment Plant in Greensboro receives discharges from both residential and industrial customers in Guilford County. From there, the plant treats the discharge before sending it into South Buffalo Creek, which feeds the Haw. However, conventional treatment systems don’t remove 1,4-Dioxane.

 

Pittsboro hit with another dose of 1,4-Dioxane from Greensboro

This story has been corrected. Greensboro told Policy Watch today that they do not believe Shamrock Environmental is the source of the contamination. The data provided by the Town of Pittsboro did not account for dilution factors in Greensboro.

Pittsboro’s drinking water took another hit of 1,4-Dioxane last week, which the town attributes to an “additional slug of contamination coming from Greensboro” on July 6, according to a press release today.

As Policy Watch reported, on June 30, the City of Greensboro illegally discharged levels of of 1,4-Dioxane 20 times higher than EPA recommended levels from its TZ Osborne wastewater treatment plant into the South Buffalo Creek, a tributary of the Haw River, according to a NC Department of Environmental Quality press release. Pittsboro sources its drinking water from the Haw River.

1,4-Dioxane is a toxic chemical used in degreasers that the EPA has classified as a likely carcinogen. There is no regulatory standard for 1,4-Dioxane, but the EPA has set a health advisory goal of 35 parts per billion for drinking water, which equals a 1-in-10,000 lifetime excess cancer risk. The surface water goal is more stringent, at 0.35 ppb, a 1-in-1 million lifetime excess cancer risk.

Testing results announced by the Town of Pittsboro show that on July 6, levels of 1,4-Dioxane in raw water — straight from the Haw River — ranged from 26.5 parts per billion to 93.6 ppb. Treated drinking water at two sources were also elevated: Chatham Forest, 66.8 ppb and the water tank, 21. 7 ppb. Treated water from the Horton tank was 1.71 ppb.

These levels are above those on July 2 when raw water contained levels of 1,4-Dioxane at 76.5 parts per billion and treated drinking water showed levels of less than 1.25 ppb.

Meanwhile, upstream Shamrock Environmental test results showed that its mixed effluent into the TZ Osborne wastewater treatment plan on July 6 and 8  reached 98.8 ppb. A “flume grab” — before Shamrock’s wastewater had been mixed — measured 466 ppb.

However, City of Greensboro spokesman Elijah Williams said Shamrock Environmental is not the source of the contamination. Accounting for dilution factors, Shamrock’s levels would need to have been much higher for it to be responsible for this spill.  Shamrock Environmental is in the waste management business, including tanker cleaning services. It was responsible for a previous spill in 2019, but Greensboro has recently ruled out the company in this incident.

Although 1,4-Dioxane is extremely difficult to remove from drinking water using conventional treatments, the Town of Pittsboro is refreshing water in their stored tanks with better-quality finished water to dilute and flush the contamination.

The TZ Osborne Wastewater Treatment Plant in Greensboro receives effluent from both residential and industrial customers in Guilford County.

Pittsboro officials in a press release said that recent rainfalls, along with flushing the town system, is helping to reduce contamination levels. The town will continue sampling until the levels of 1,4-Dioxane are not detected.

Pittsboro expects to release results of its sampling through July 9 tomorrow.

Also, the Environmental Management Commission is scheduled to discuss 1,4-Dioxane at its meeting tomorrow, which begins at 9 a.m.