Sweeney Treatment Enhancements Project
9/16/22 CONSTRUCTION UPDATE:
Granular Activated Carbon (GAC) has been loaded into seven of the eight deep-bed filters. This week, crews also completed roofing coping installation and installed lighting in the GAC facility’s stairwells. Sweeney staff completed training on operating and maintaining key equipment throughout the facility.
After each filter is filled with GAC, the GAC media is washed and rinsed for a period of time to prepare the media for service and to ensure that important water treatment parameters, such as pH, are within operational limits. CFPUA staff then inspects and tests the completed filters to ensure they can perform together as a complete treatment system.
Next week, GAC will be loaded into the eighth and final deep-bed filter and washing and testing will continue on the most recently filled filters.
Construction is nearing completion on a project to add eight new granular activated carbon (GAC) filters to Sweeney Water Treatment Plant, which draws from the Cape Fear River and provides drinking water to about 80 percent of CFPUA's customers.
The GAC filters emerged as the best option for Sweeney to reduce GenX and other PFAS compounds in the river following an extensive pilot study that also examined reverse osmosis and ion-exchange media. Models have shown that the new GAC filters will be very effective at removing Chemours' PFAS compounds in water sourced from the Cape Fear River, reducing GenX close to or at levels where it cannot be detected in treated drinking water.
The PFAS found in the Cape Fear result largely from decades of releases by Chemours and DuPont from their chemical plant on the Bladen-Cumberland county line, about 100 miles upriver from Wilmington.
The CFPUA Board awarded a $35.9 million contract to Adams-Robinson Enterprises Inc. for construction of the project. It is being funded through the sale of revenue bonds.
The project is anticipated to go online in 2022. Annual operating costs are estimated to be $3.7 million for Fiscal Year 2023 and at least $5 million in subsequent years.
Until the new filters are finished, CFPUA has implemented a program to replace media in existing filters at Sweeney. Those steps have resulted in some reductions but are unsuited as a long-term solution.
As Chemours and its predecessor DuPont are largely responsible for the PFAS compounds that continue to be found in the Cape Fear, CFPUA has filed a federal lawsuit to recover costs and damages related to the companies’ releases from their chemical plant.
Resolution of the lawsuit likely is several years away, and predicting what that might entail, including any monetary award, is very difficult.
CFPUA is public entity, funded by ratepayers and operating without any profit. CFPUA customers would be the beneficiaries of any award received from the lawsuit.