{"hq_id":"hq-p-out-000077","name":"Municipal Compost and PFAS Contamination from Biosolid Amendment (Per- and Polyfluoroalkyl Substances in Yard Waste and Food Scrap Compost)","category":{"primary":"outdoor_environment","secondary":"soil_amendment","tags":["PFAS","compost","biosolids","municipal","soil contamination","food scrap","yard waste","forever chemicals","garden"]},"product_tier":"OUT","overall_risk_level":"moderate","description":"Municipal compost programs that incorporate biosolids (treated sewage sludge) or accept PFAS-contaminated food packaging in organic waste streams have become a significant pathway for per- and polyfluoroalkyl substances (PFAS) contamination in residential garden soil. PFAS — persistent synthetic fluorinated compounds used in food packaging, firefighting foam, nonstick coatings, and stain-resistant textiles — concentrate in wastewater treatment biosolids at levels of 10-1,000 ppb and transfer directly to compost. Studies by the Sierra Club and state environmental agencies have detected PFAS in commercially sold compost at levels exceeding 10 ppb total PFAS in multiple states, with PFOA and PFOS accounting for the dominant fraction. Home gardeners applying this compost grow food in PFAS-contaminated soil, creating a direct dietary exposure pathway. Maine became the first US state to ban land application of biosolids containing PFAS (2022), and several states now test compost for PFAS contamination. The irreversibility of PFAS soil contamination — these molecules do not biodegrade — means a single season of contaminated compost application can render garden soil permanently impaired for food production.","synthesis":{"derived_risk_level":"severe","synthesis_confidence":0.851,"synthesis_method":"compound_composition","context_used":"human_child","context_source":"product_users","exposure_modifier":1,"vulnerability_escalated":false,"escalation_reason":null,"compounds_resolved":1,"compounds_total":1,"synthesis_date":"2026-03-27","synthesis_version":"1.0.0"},"hazard_summary":{"sensitive_populations":"home gardeners consuming PFAS-contaminated produce, children playing in amended soil, pregnant women (PFAS crosses placenta), communities reliant on well water near biosolid-applied fields","overall_risk":"moderate","primary_concerns":["PFAS in biosolid-amended compost is permanent — no biodegradation pathway exists","Leafy green vegetables accumulate 10-100x more PFAS from soil than fruiting crops","No federal PFAS limits for compost or biosolids sold to consumers","One season of contaminated compost can render garden soil permanently impaired for food production"],"exposure_routes":"Ingestion (consumption of PFAS-contaminated homegrown produce; hand-to-mouth for children in garden soil). Dermal (direct handling of contaminated compost and soil). Groundwater (leaching from amended soil into wells)."},"exposure":{"routes":["ingestion","dermal"],"contact_types":["ingestion_dietary","dermal_direct"],"users":["adult","child"],"duration":"chronic","frequency":"seasonal","scenarios":["Gardener applies PFAS-contaminated municipal compost to vegetable beds — PFAS uptake into leafy greens and root vegetables","Child plays in garden soil amended with contaminated compost — dermal and hand-to-mouth exposure","Household consumes homegrown produce with PFAS bioaccumulated from soil","Compost runoff contaminates groundwater and neighboring properties"],"notes":"PFAS in biosolids: wastewater treatment concentrates PFAS from household and industrial sources into biosolids. Concentrations: PFOS 10-800 ppb, PFOA 5-400 ppb in US biosolids (national survey, Venkatesan & Halden, 2013). Plant uptake: PFAS are taken up by roots and translocated to edible portions; leafy greens accumulate 10-100x more PFAS than fruiting vegetables. Maine LD 1911 (2022): first US state to ban biosolid land application due to PFAS. Vermont, California, and Washington testing compost programs for PFAS. No federal standard for PFAS in compost or biosolids — EPA has proposed but not finalized limits."},"consumer_guidance":{"usage_warning":"Ask your municipal compost provider whether biosolids are included in the feedstock and whether PFAS testing is performed. Avoid compost that incorporates sewage sludge or biosolids if you plan to grow edible crops. If you have used biosolid-amended compost, consider testing soil for PFAS (available through commercial labs for $150-300). Grow fruiting crops (tomatoes, peppers) rather than leafy greens in potentially affected beds, as they accumulate less PFAS.","safer_alternatives":["Biosolid-free compost made exclusively from yard waste and food scraps (verified PFAS-tested)","Home composting from known clean inputs (no PFAS-containing food packaging)","Aged manure from farms not using biosolids on pasture","Peat-free commercial potting mixes without biosolid components","Raised beds with purchased clean soil for edible gardens"]},"regulatory":{"applicable_regulations":[{"jurisdiction":"USA","regulation":"Maine LD 1911 — Ban on Biosolid Land Application Due to PFAS","citation":"Maine Public Law Chapter 641 (2022); 38 MRSA §1612","requirements":"Maine banned land application of biosolids (sewage sludge) statewide effective 2022 due to PFAS contamination of farms and wells. Several states (Vermont, California, Washington) now require PFAS testing of compost products. No federal PFAS limit for compost or biosolids — EPA proposed PFAS limits under CERCLA but has not established compost-specific standards.","compliance_status":null,"effective_date":"2022-08-01","enforcing_agency":"Maine DEP; state environmental agencies","penalties":null,"source_ref":null}],"certifications":[],"labeling":{"required_disclosures":[],"prop65_warning":{"required":null,"chemicals":[],"endpoint":null,"notes":null},"ghs_labeling":{"required":null,"signal_word":null,"pictograms":[],"hazard_statements":[],"notes":null},"hidden_ingredients":{"trade_secret_protected":null,"categories_hidden":[],"estimated_count":null,"known_concerns":null,"notes":null},"notes":null},"recalls":[],"regulatory_gap":null,"notes":null},"lifecycle":{"recyclable":false,"disposal_guidance":"Do not dispose of PFAS-contaminated compost or soil in waterways. Contaminated soil should remain in place (PFAS does not volatilize) — cover with clean soil if needed. Report suspected contamination to state environmental agency.","hazardous_waste":false,"expected_lifespan":"PFAS persists indefinitely in soil — no degradation pathway under ambient conditions"},"formulation":{"form":"varies","key_ingredients":[],"certifications":[]},"materials":{"common":[],"concerning":[],"preferred":[]},"compound_composition":[{"hq_id":"hq-c-mix-000001","compound_name":null,"role":"contaminant_class","typical_concentration":"PFAS (PFOA + PFOS dominant) in biosolid-amended compost at 10-1,000 ppb; soil accumulation is permanent"}],"identifiers":{"common_names":["municipal compost and pfas contamination from biosolid amendment (per- and polyfluoroalkyl substances in yard waste and food scrap compost)"],"aliases":[],"manufacturer":null,"brands":[]},"brand_examples":[],"sources":[{"type":"expert_curation","name":"ALETHEIA Safety Database","date":"2026-03-26"}],"meta":{"schema_version":"4.0.0","last_updated":"2026-03-26","timestamp":"2026-05-01T14:32:12.572Z"}}