PFAS Removal

The City of Wixom WWTP consists of approximately 81 miles of a sewer network and a tertiary treatment plant with a capacity of approximately three million gallons per day. The WWTP treats residential, commercial, and industrial wastewater.

The Challenge
The City of Wixom Wastewater Treatment Plant (WWTP) needed to remove per- and poly-fluoroalkyl substances (PFAS) from approximately 1.0 million gallons of impacted wastewater sludge. 

ERG’s Solution

ERG provided consulting services for removal of PFAS contaminants and assisted the City of Wixom with the grant application to obtain funding from the Michigan Department of Environment, Great Lakes, and Energy. The treatment system was designed to remove PFAS to an acceptable level so that the treated water could be discharged under the WWTP’s National Pollutant Discharge Elimination System (NPDES) permit. The objective was to remove perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) below 10 nanogram per liter (ng/l). The concentration of PFOS in the impacted sludge was above 15,000 ng/l.

ERG conducted preliminary testing to determine appropriate coagulant and flocculant dosing to remove total suspended solids via the dissolved air floatation (DAF). Several indicators including the clarity of the effluent via the DAF and granular activated carbon (GAC) media were used as indicators of the presence of PFOS above 10 ng/l. The treated liquid via GAC and ion exchange resins was discharged to the WWTP’s headwork upon verification via the analytical data.  

Client Results:

• Average PFOS concentration in the treated liquid was less than 3.5 ng/l and PFOA was not detected

• Grant funding was secured for the City of Wixom

• More than 99% removal of other PFAS was accomplished

 SERVICES PROVIDED

PFAS Removal System Design

Treatment System Management and Monitoring

Discharge Strategies and Reporting