AlexRenew eyes mobile drying units as Virginia advances PFAS biosolids restrictions

AlexRenew eyes mobile drying units as Virginia advances PFAS biosolids restrictionsThe Alexandria utility is exploring interim thermal treatment options to bridge the gap between pending state regulations and the completion of its permanent solids handling infrastructure.

A legislative compromise on Virginia bills HB 1443 and SB 386 sets PFAS concentration limits for land application effective January 1, 2027.

AlexRenew CEO Justin Carl confirmed the utility is evaluating mobile dryer rentals to manage solids volume before its permanent facility comes online.

The new rules would ban land application for biosolids exceeding 50 parts per trillion (ppt) of PFAS and restrict rates for concentrations between 25 and 50 ppt.

AlexRenew's current biosolids average between 18 and 20 ppt, placing the utility just below the new regulatory thresholds.

Alexandria Renew Enterprises (AlexRenew) is actively exploring interim thermal drying technologies to ensure compliance with emerging state regulations regarding per- and polyfluoroalkyl substances (PFAS) in biosolids. During a February 17 Board of Directors meeting, General Counsel Amanda Waters reported that stakeholders in the Virginia General Assembly had reached a compromise that morning on House Bill 1443 and Senate Bill 386. The legislation, which AlexRenew now supports, establishes a tiered framework for the land application of biosolids based on PFAS concentrations. Under the compromise, which is slated to take effect on January 1, 2027, utilities will be required to conduct quarterly testing using a rolling 12-month average. Land application will be prohibited for biosolids with PFAS concentrations exceeding 50 parts per trillion (ppt). Material testing between 25 and 50 ppt will be subject to reduced application rates, while concentrations below 25 ppt will face no restrictions. AlexRenew currently averages PFAS levels of approximately 18 to 20 ppt. While this falls within the safe zone of the proposed legislation, CEO Justin Carl noted that the utility is investigating "pilot technologies" to mitigate risk between the 2027 effective date and the completion of the utility's permanent solids handling upgrades. "We are looking at ways to reduce our volume in the interim," Carl told the Board. He described a potential solution involving "bringing a dryer on the back of an 18-wheeler" to operate for approximately two years until the utility's permanent solids thermal dryer is commissioned. The permanent dryer is a key component of the utility's ongoing PhaseForward capital program, specifically the Biosolids Diversification Project, which involves reconstructing Building C to accommodate the new infrastructure. The legislative compromise represents a resolution between diverging initial approaches. While House Bill 1443 originally proposed limits of 50 parts per billion for specific compounds, the Senate version sought to ban land application for any detectable trace of PFAS—a standard Waters described as "impossible" for utilities to meet. The final agreement bridges these positions and outlines a trajectory for stricter cumulative limits beginning in 2029, providing utilities a window to develop alternative disposal or treatment methods, such as incineration or advanced thermal drying.