Greywater Reuse and PFAS
Greywater recycling—collecting and reusing household wastewater from laundry, bathtubs, and sinks for toilet flushing and irrigation—is promoted as a water conservation strategy. However, greywater contains PFAS shed from PFAS-treated clothing, bedding, and textiles, creating concentration and reuse pathways for PFAS that may complicate simple sustainability calculations.
PFAS in Laundry Greywater
Washing PFAS-treated textiles—stain-resistant clothing, water-resistant outdoor gear, PFAS-treated bedding—releases PFAS into laundry water. Studies find laundry greywater contains measurable PFAS at concentrations of 50–500 ng/L, varying by textile type and washing conditions. High-temperature washing increases PFAS release from treated fabrics compared to cold water washing.
Reuse and Exposure Pathways
Greywater used for garden irrigation creates soil PFAS accumulation that can transfer to crops. Toilet flushing with PFAS-containing greywater does not create direct exposure but adds PFAS to municipal wastewater treatment systems. Simple greywater systems without PFAS treatment may transfer laundry PFAS to new exposure environments rather than reducing total household PFAS burden.
Informed Greywater System Design
Greywater system designers in PFAS-aware communities should assess the PFAS content of source waters and reuse applications. Excluding laundry greywater from garden irrigation systems—using only bath and sink water—reduces PFAS input to soil. Purchasing PFAS-free textiles eliminates the source, making greywater reuse genuinely beneficial without chemical transfer concerns