{"hq_id":"hq-p-hom-000224","name":"Greywater Reuse System (Surfactant, Pathogen, Landscape Irrigation)","category":{"primary":"household","secondary":"water","tags":["greywater","reuse","irrigation","surfactant","laundry","shower","landscape","drought"]},"product_tier":"HOM","overall_risk_level":"low","description":"Greywater systems diverting laundry, shower, and bathroom sink water to landscape irrigation. Greywater contains soap/surfactant residue, skin cells, hair, bacteria, and laundry chemical residue. Not suitable for food garden irrigation (pathogen risk). Boron in some detergents is phytotoxic. Sodium from water softener salt accumulates in soil. Laundry-to-landscape is simplest system (gravity-fed, no treatment, permitted in many states without permit). Branched drain distributes to multiple planting zones.","synthesis":{"derived_risk_level":"moderate","synthesis_confidence":0.628,"synthesis_method":"compound_composition","context_used":"human_adult","context_source":"product_users","exposure_modifier":0.85,"vulnerability_escalated":false,"escalation_reason":null,"compounds_resolved":2,"compounds_total":2,"synthesis_date":"2026-05-09","synthesis_version":"1.2.0","methodology_note":"exposure_modifier and adjusted_magnitude are computed from ALETHEIA-calibrated heuristics (route × duration × frequency multipliers, clamped to [0.5, 1.4]). Multipliers are directionally informed by EPA Exposure Factors Handbook (2011) and CalEPA OEHHA but are not regulatory consensus. See /api/methodology for full disclosure."},"hazard_summary":{"sensitive_populations":"children (greywater-irrigated play areas), food garden crops","overall_risk":"low","primary_concerns":["Not suitable for food garden irrigation (pathogen risk — root vegetables, leafy greens)","Soil sodium accumulation from softened water or high-sodium detergent","Boron in some detergents is phytotoxic to sensitive plants","Subsurface irrigation eliminates human contact risk"],"exposure_routes":"Minimal human exposure with subsurface irrigation system"},"exposure":{"routes":["dermal"],"contact_types":["skin_brief"],"users":["adult"],"duration":"minutes","frequency":"weekly","scenarios":["Landscape irrigation with laundry/shower greywater","Surfactant/detergent residue contacting plant roots","Soil sodium accumulation from softened water greywater","Children playing in greywater-irrigated landscape (minimal contact)"],"notes":"California greywater code (CPC Chapter 16A): laundry-to-landscape systems exempt from permit in most cases. Use greywater-compatible detergent (low sodium, no boron): Oasis, Sal Suds, Ecos. Do NOT use greywater on root vegetables or leafy greens (pathogen risk). Subsurface irrigation (not surface spray) eliminates human contact. Rotate irrigation zones to prevent soil salt buildup. Greywater reuse can save 15-25 gallons/day per household."},"consumer_guidance":{"usage_warning":"Use greywater for landscape irrigation ONLY — not food gardens (root vegetables, leafy greens). Use greywater-compatible detergent (low sodium, no boron). Subsurface irrigation (not spray). Rotate zones to prevent salt buildup. Check local code — laundry-to-landscape often permit-exempt.","safer_alternatives":["Laundry-to-landscape gravity system (simplest, often permit-exempt)","Greywater-compatible detergent (Oasis, Sal Suds, Ecos)","Subsurface drip irrigation (eliminates human contact)","Mulch basin distribution (simple, effective, no spray)"],"red_flags":[{"indicator":"Water quality not tested or treatment system not maintained","meaning":"Unknown contaminant exposure or treatment failure.","action":"Test water. Maintain treatment systems per manufacturer schedule."}],"green_flags":[{"indicator":"NSF-certified treatment system with current maintenance","meaning":"Verified contaminant reduction with functioning system.","verification":"Check NSF certification and maintenance schedule compliance."}],"what_to_ask":[{"question":"What specific contaminants does this system remove, and at what efficiency?","why_it_matters":"No single system removes everything. Match treatment to your specific water quality.","good_answer":"NSF-certified for specific contaminants with published reduction data.","bad_answer":"Generic claims without specific contaminant testing."}],"alternatives":[{"name":"Laundry-to-landscape gravity system","notes":"simplest, often permit-exempt"},{"name":"Greywater-compatible detergent","notes":"Oasis, Sal Suds, Ecos"},{"name":"Subsurface drip irrigation","notes":"eliminates human contact"}]},"regulatory":{"applicable_regulations":[{"jurisdiction":"USA -- California","regulation":"California Plumbing Code Chapter 16A (Greywater)","citation":"CPC Chapter 16A","requirements":"Laundry-to-landscape systems: permit-exempt with proper installation. Subsurface only. No food crop irrigation. Minimum setbacks from wells and property lines.","compliance_status":null,"effective_date":null,"enforcing_agency":"Local building dept","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":"System components: regular waste. Greywater itself: directed to landscape.","hazardous_waste":false,"expected_lifespan":"10-20_years"},"formulation":{"form":"varies","key_ingredients":[{"hq_id":"hq-c-org-000717","name":"Sodium lauryl sulfate","role":"surfactant_residue","concentration_pct":"trace"},{"hq_id":"hq-c-org-000011","name":"Formaldehyde","role":"trace","concentration_pct":"trace"}],"certifications":[]},"materials":{"common":[],"concerning":[],"preferred":[]},"compound_composition":[{"hq_id":"hq-c-org-000717","compound_name":null,"role":"surfactant_residue","typical_concentration":"trace"},{"hq_id":"hq-c-org-000011","compound_name":null,"role":"trace","typical_concentration":"trace"}],"identifiers":{"common_names":["greywater reuse system (surfactant, pathogen, landscape irrigation)"],"aliases":[],"manufacturer":null,"brands":[]},"brand_examples":[{"brand":"Miracle-Gro","manufacturer":"ScottsMiracle-Gro","market_position":"mass_market","notable":"Market-leading garden soil"},{"brand":"Black Gold","manufacturer":"Sun Gro Horticulture","market_position":"mass_market","notable":"Organic potting soil"},{"brand":"FoxFarm","manufacturer":"FoxFarm","market_position":"premium","notable":"Premium garden soil mixes"}],"brand_examples_disclaimer":"Representative branded products of this category. Concerning ingredients listed in materials.concerning[] apply to the category, not necessarily to every named brand. Specific formulations vary by SKU and may have changed since this record was written; consult the brand's current ingredient label before drawing brand-level conclusions.","sources":[{"type":"expert_curation","name":"ALETHEIA Safety Database","date":"2026-03-25"},{"type":"regulation","title":"California Plumbing Code Chapter 16A (Greywater) (CPC Chapter 16A)","jurisdiction":"USA -- California","citation":"CPC Chapter 16A","id":"src_8d9026c7"},{"id":"src_001","type":"database","title":"PubChem Compound CID 3423265","url":"https://pubchem.ncbi.nlm.nih.gov/compound/3423265","accessed":"2026-03-12","notes":"Chemical identity, properties, safety data","inherited_from_compound":"hq-c-org-000717"},{"id":"src_002","type":"epa","title":"EPA CompTox Chemicals Dashboard — DTXSID1026031","url":"https://comptox.epa.gov/dashboard/chemical/details/DTXSID1026031","accessed":"2026-03-12","notes":"Hazard, exposure, and toxicity data","inherited_from_compound":"hq-c-org-000717"},{"id":"iarc_100f_form","type":"regulatory","title":"IARC Monographs Volume 100F: Formaldehyde","year":2012,"inherited_from_compound":"hq-c-org-000011"},{"id":"epa_form_iris","type":"regulatory","title":"US EPA IRIS Assessment: Formaldehyde (draft)","year":2010,"inherited_from_compound":"hq-c-org-000011"}],"meta":{"schema_version":"4.0.0","last_updated":"2026-03-25","timestamp":"2026-05-14T01:28:29.447Z"}}