By Greg Barnes
The state Department of Environmental Quality will require 25 municipalities in the Cape Fear River Basin to begin monthly monitoring this summer for unregulated but potentially cancer-causing chemicals known as emerging contaminants.
The DEQ’s Division of Water Resources recently sent letters to municipalities in the basin with pretreatment wastewater programs, saying monitoring would begin in June for 1,4 dioxane and a set of fluorinated chemical substances known as PFAS.
The purpose of the new requirement is to identify which municipalities are receiving these pollutants at their wastewater treatment plants and to work with them to reduce the contaminants at their industrial source, DEQ spokeswoman Sarah Young said. Municipalities have pretreatment programs that are designed to control the discharge of industrial wastewater into municipal treatment plants.
Elevated concentrations of 1,4 dioxane and PFAS have been found throughout the Cape Fear river basin, from around Greensboro to the coast. The chemicals do not yet have federal water quality standards, but 1,4 dioxane is listed by the U.S. Environmental Protection Agency as a probable carcinogen.
Studies have also shown that PFAS ingestion over a lifetime raises the risk for thyroid disease, liver damage, increased risk of certain cancers, elevated cholesterol levels and decreased vaccination response.
1,4-dioxane is a solvent stabilizer used for a wide variety of industrial and manufacturing purposes. The compound can be found in industrial solvents, paint strippers and varnishes and is often produced as a by-product of chemical processes to manufacture soaps, plastics and other consumer products.
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 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.
PFAS compounds are most often associated with nonstick coatings, plating operations, firefighting foams and stain- and water-resistant treatments for clothing, furniture and carpet.
Fayetteville is among the cities that have already been routinely monitoring for 1,4 dioxane in drinking water, said Mick Noland, chief operating officer for the city’s Public Works Commission.
Noland said the average of test results over the last 12 months show a concentration of 1,4 dioxane at 0.63 parts per billion in Fayetteville’s drinking water. The EPA’s health advisory is 35 parts per billion. A person who drinks water over a lifetime at the EPA’s health advisory level stands a 1 in 10,000 chance of getting cancer.
North Carolina’s health standard for 1,4 dioxane in rivers, streams and all other surface waters is 0.35 parts per billion. At that concentration, a person stands a 1 in 1 million chance of developing cancer over a lifetime. Drinking water levels in Fayetteville are nearly double the state’s stream water standard, far less than it had been.
Much higher elsewhere
Upstream of Fayetteville, much higher concentrations of 1,4 dioxane have been detected. Around 2014, researchers conducting tests for the DEQ found the highest level of 1,4 dioxane at 1,030 parts per billion in the Haw River near Reidsville, 25 miles north of Greensboro. The Haw flows into Jordan Lake and the Cape Fear River, from which Sanford, Harnett County, Fayetteville, Wilmington and other municipalities get their drinking water.
The levels have since come down. Noland believes the reduction is due in part to action taken by Greensboro against polluters, but he said the concentrations tend to fluctuate, decreasing at times of high river flow because of dilution.
Noland said Fayetteville is among a group of downstream utilities, along with those in Greensboro, Asheboro and Reidsville, that have been collecting samples and working with the Division of Water Resources to reduce the levels of 1,4 dioxane.
Part of the intent of the division’s new monitoring requirement, which was made public Monday, is to develop a basin-wide strategy to achieve compliance with the state’s health advisory standards for 1,4 dioxane in streams and rivers used for drinking water of 0.35 parts per billion, Noland said.
Many industries in the Triad area discharge wastewater containing 1,4 dioxane directly into municipal sewer systems, and it doesn’t take much of the stuff to foul the water. Adding only about a drop of 1,4 dioxane into a large tanker truck of water would be enough to increase people’s cancer risk.
It is extremely difficult, and expensive, to screen the chemical before the treated wastewater is poured back into rivers or streams. Researchers have found that 1,4 dioxane is also coming from fields used to store the treatment plants’ sludge and from landfills. Sludge is the residue that accumulates in sewage treatment plants as a solid, semisolid or slurry material. The sludge — or biosolids — goes through more treatment processes before being applied to land, sometimes as fertilizer.
Progress too slow
State Sen. Kirk deViere, a Democrat from Cumberland County, said he and other senators met with the DEQ on Monday to discuss the new monitoring requirement, as well as other environmental concerns.
In an email, deViere called the monitoring requirement “a good first step in an ongoing strategy to address emerging compounds and better understanding of their presence at wastewater treatment plants.” But he added that he doesn’t think the state is moving fast enough to solve its multitude of environmental problems.
deViere is a primary sponsor of a bill pending in the General Assembly that would establish a PFAS task force to identify and analyze all PFAS in the Lower Cape Fear River basin, identify the sources of the PFAS, establish maximum health standards for exposure to the contaminants and provide safe drinking water for people facing contamination at high levels. The bill is not expected to make it out of committee.
State Rep. Pricey Harrison (D-Greensboro), also called the new monitoring requirements a good first step, but she said, “it must be followed with stringent limits that require sources to control or eliminate their discharges.”
Rather than having wastewater treatment plants develop a monitoring plan to determine the sources of the pollution, Harrison said, the treatment plants or the DEQ should require the industries to conduct their own monitoring.
“That would expose the major sources a lot more quickly than having the (wastewater treatment plants) do the investigation on their own,” she said.
Harrison also said the DEQ should impose limits in the National Pollutant Discharge Elimination System permits that industries are required to operate under. The wastewater treatment plants would then include those limits in their pretreatment permits for industrial users, she said. Harrison is a primary sponsor of a bill that would do that. The bill is unlikely to pass, she has said.
PFAS threat
The concern over PFAS in the Cape Fear River basin has grown since the Wilmington Star-News made public in June 2017 that GenX — one of thousands of PFAS chemicals — was found in high concentrations in Wilmington’s drinking water.
Researchers, who had detected PFAS in the upper reaches of the basin as early as 2006, have recently stepped up monitoring efforts there. Last summer, those researchers found a set of seven PFAS measuring a combined 1,076 parts per trillion in the Haw River at Bynum, an old textile mill community near Pittsboro.
Pittsboro is the only municipality that draws its drinking water directly from the Haw River. It has been using powdered activated carbon, which N.C. State University researcher Detlef Knappe called “somewhat effective” in removing PFOA and PFOS — the only types of PFAS in which the EPA has set health advisory levels.
On the day the samples were taken, Knappe said in an email, Pittsboro’s drinking water measured a combined 57 parts per trillion for the two compounds, which was below the 70 parts per trillion health advisory.
Late last month, a consultant presented the town with a preliminary report showing it could cost millions to more effectively filter out PFAS contamination.
Greensboro already is taking steps to rid PFAS from its drinking water, agreeing to spend $31 million on an advanced granular activated carbon filtration system. New Hanover and Brunswick counties are also installing new systems.
Greensboro says much of the PFAS found the city’s drinking water comes from firefighting foam that had been used at Piedmont Triad International Airport for training purposes. In August, the combined level of PFOA and PFOS in Greensboro’s drinking water measured 96 parts per trillion, which was above the EPA’s health advisory level. The concentrations are now below that level.
Bipartisan bills pending in both chambers of the General Assembly would ban the manufacture, sale or use of firefighting foam containing PFAS in the state.
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