Cape Fear Public Utility Authority's PFAS filters sit in a cavernous room, full of metal guard rails around giant vats of black water. The eight vats are 24 feed deep, full of granular activated carbon, or GAC. The black granules remove forever chemicals and other tough contaminants from the water, which slowly seeps through before moving on to a final step of ultraviolet light treatment.
The GAC system started filtering in October of 2022, according to Greg Purcell, Water Control Supervisor at Cape Fear Public Utility Authority.
“Now, there's a lot of facilities across the nation who are following suit. CFPUA was ahead of the curve. Before regulation was even coming out, they were in the design phase," he said.
GAC is close to the final step at CFPUA, so the water is already clean of many contaminants by the time it gets to these vats. After the water comes in from the Cape Fear River's intake upstream of Wilmington, ultra pulsators remove silt and other solids. Then the water goes through a process with ozone, Purcell said.
"The ozone is used to remove organics. It's kind of it's an oxidizer, so it helps remove iron and manganese and stuff like that," he said.
Next comes a process called flocculation, which uses chemicals and electricity to remove more contaminants. It goes through clarifiers, then a biofilter, before finally coming to the newly added GAC filtration system with its eight vats of water.
It works like this: water in each vat slowly filters through 375,000 pounds of extremely porous carbon. CFPUA executive director Kenneth Waldroup explained how it works. "You have the static electricity effect, bringing contaminants out and being absorbed onto that media. But the media will get saturated.”
The plant has to exchange the GAC eight to 10 times a year to make sure it can keep pulling out PFAS. If the GAC gets saturated, it starts releasing contaminants back into the water, so it needs to be regenerated regularly. But that process isn't simple, according to CFPUA Executive Director Kenneth Waldroup.
"It gets shipped out to a regeneration facility: Buffalo, New York, or Ohio where it's put in a kiln, and it's heated," Waldroup said. "And that heating process drives out the contaminants. It also destroys some of the GAC.”
It’s expensive to install these filters and to keep them running: it costs the plant an additional $4.7 million a year to run the GAC component of the plant — doubling the plant’s annual costs. And building it in the first place cost the utility $44 million, being paid by members of the Wilmington community — not the polluters.
CFPUA is ahead of the curve on PFAS for one reason: it’s uniquely contaminated compared to many other utilities in the state. As Waldroup explains, the plant serves Wilmington and New Hanover County, at the mouth of the Cape Fear River.
"So unfortunately, this utility was impacted by industrialization and industrial discharges from a PFAS manufacturing facility at approximately 50 miles upstream of our intake, known as the Fayetteville works facility.”
That facility, previously owned by DuPont and now owned by Chemours, has discharged per and poly-fluoroalkyl substances into the Cape Fear for decades. Recently, its ongoing pollution has largely been halted, but the surrounding environment is contaminated enough to continue leaching PFAS into the water — alongside other pollution sources.
The community discovered the pollution in 2017, and CFPUA looked into how best to filter the stuff out.
So, when the EPA announced its finalized National Primary Drinking Water Regulation for six PFAS earlier this month, CFPUA was already in compliance. Not only is it already testing for PFAS, like all utilities will need to in the next three years — it is also already filtering out its contaminants to the strict levels that will be required by the federal agency in about five years.
The American Water Works Association — an industry group - estimates the cost to implement the rule could exceed $2.5 billion to $3.2 billion annually — more than double EPA estimates. The Biden administration has only put aside $9 billion for water utility upgrades to manage the new drinking water standards.
"Right now, it will fall on local utilities and their ratepayers," Waldroup said. "We in the water industry are strongly encouraging the federal government to step forward as they did at the advent of the Safe Drinking Water Act and the Clean Water Act and offer more robust funding.”
With thousands of utilities across the country expected to require additional filtration to keep out PFAS, it is forecast to be a significant logistical and financial challenge for the country.
And while some utilities, like CFPUA, are suing their known polluters, others have no clear company to blame — and may need to foot the bill by raising costs for customers. CFPUA has already raised costs to help support the Sweeney improvements — by a modest amount, roughly $5 per month for an average customer. But, while CFPUA remains confident it will win its suit against Chemours in court, or receive a significant settlement, at some point in the future, customers are unlikely to get reimbursed for the increased rates they will have paid before then and now.
