{"hq_id":"hq-p-hom-000166","name":"Private Well Water (Unregulated Contaminants)","category":{"primary":"household","secondary":"water_quality","tags":["well water","arsenic","uranium","nitrate","bacteria","unregulated"]},"product_tier":"HOM","overall_risk_level":"moderate_to_high","description":"Private residential wells serving approximately 43 million Americans (13% of population). Private wells are NOT regulated under the Safe Drinking Water Act — no federal testing, treatment, or reporting requirements. Common contaminants: arsenic, uranium, nitrate, manganese, bacteria (E. coli, coliform), radon, VOCs (near industrial sites), pesticides (agricultural areas). USGS: 20% of tested private wells exceeded at least one EPA health-based standard.","synthesis":{"derived_risk_level":"severe","synthesis_confidence":0.708,"synthesis_method":"compound_composition","context_used":"human_infant","context_source":"product_users","exposure_modifier":1.4,"vulnerability_escalated":true,"escalation_reason":"Infant exposure group","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":"infants (nitrate — blue baby syndrome), all well users (no regulatory oversight)","overall_risk":"moderate_to_high","primary_concerns":["NO federal regulation — 43 million Americans unprotected by SDWA","20% of tested private wells exceed at least one EPA health standard (USGS)","Arsenic in groundwater — IARC Group 1, geological source in many regions","Nitrate from agricultural runoff — infant methemoglobinemia risk"],"exposure_routes":"Oral (drinking, cooking); inhalation (radon volatilization during bathing)"},"exposure":{"routes":["oral","inhalation"],"contact_types":["oral_direct","inhalation"],"users":["adult","child","infant"],"duration":"continuous","frequency":"daily","scenarios":["Daily drinking, cooking, and bathing with untested well water","Arsenic in well water — geological, not anthropogenic (New England, Southwest)","Nitrate from agricultural runoff — infant methemoglobinemia (blue baby syndrome)","Radon in well water volatilizing during showering (inhalation)"],"notes":"EPA recommends annual testing of private wells for bacteria and nitrate, and periodic testing for arsenic, uranium, and other contaminants based on geology. 43 million Americans on private wells have zero regulatory protection. Testing costs $100-500 depending on analyte panel. State cooperative extension services often provide subsidized testing."},"consumer_guidance":{"usage_warning":"Test well water annually for bacteria and nitrate. Test for arsenic, uranium, manganese, and radon based on regional geology (check USGS maps). Do not rely on taste or clarity — arsenic and uranium are odorless and colorless. Install treatment system matched to specific contaminants found.","safer_alternatives":["Annual professional well water testing (comprehensive panel)","Whole-house treatment system matched to test results","Point-of-use reverse osmosis for drinking water","State cooperative extension subsidized testing programs"],"red_flags":[{"indicator":"Aging infrastructure without inspection or testing","meaning":"Degradation increases contamination risk over time.","action":"Test or inspect per recommended schedule."}],"green_flags":[{"indicator":"NSF or third-party certification","meaning":"Independent testing for safety standards.","verification":"Check for NSF, UL, or equivalent certification marks."}],"what_to_ask":[{"question":"What certifications does this product or system carry?","why_it_matters":"Certification verifies compliance with health-based standards.","good_answer":"NSF, UL, or equivalent third-party certification.","bad_answer":"No certification or self-certified."}],"alternatives":[{"name":"Annual professional well water testing","notes":"comprehensive panel"},{"name":"Whole-house treatment system matched to test results","notes":"Alternative"},{"name":"Point-of-use reverse osmosis for drinking water","notes":"Alternative"}]},"regulatory":{"applicable_regulations":[{"jurisdiction":"USA","regulation":"Safe Drinking Water Act does NOT cover private wells","citation":"42 U.S.C. 300f-300j","requirements":"SDWA regulates public water systems only. Private wells (serving <25 people) are exempt. No federal testing, treatment, or monitoring requirements.","compliance_status":null,"effective_date":null,"enforcing_agency":"None (no federal jurisdiction)","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":"Well maintenance: annual inspection by licensed well contractor.","hazardous_waste":false,"expected_lifespan":"25-50_years"},"formulation":{"form":"varies","key_ingredients":[{"hq_id":"hq-c-ino-000002","name":"Arsenic (inorganic)","role":"geological_contaminant","concentration_pct":"1-100+ ppb"},{"hq_id":"hq-c-ino-000040","name":"Uranium-235 (²³⁵U) and natural uranium","role":"geological_contaminant","concentration_pct":"trace-30+ ppb"}],"certifications":[]},"materials":{"common":[],"concerning":[],"preferred":[]},"compound_composition":[{"hq_id":"hq-c-ino-000002","compound_name":null,"role":"geological_contaminant","typical_concentration":"1-100+ ppb"},{"hq_id":"hq-c-ino-000040","compound_name":null,"role":"geological_contaminant","typical_concentration":"trace-30+ ppb"}],"identifiers":{"common_names":["private well water (unregulated contaminants)"],"aliases":[],"manufacturer":null,"brands":[]},"brand_examples":[{"brand":"SC Johnson","manufacturer":"SC Johnson","market_position":"mass_market","notable":"Household product conglomerate"},{"brand":"Clorox","manufacturer":"Clorox","market_position":"mass_market","notable":"Household cleaning market leader"},{"brand":"3M","manufacturer":"3M","market_position":"mass_market","notable":"Home safety and maintenance products"}],"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":"Safe Drinking Water Act does NOT cover private wells (42 U.S.C. 300f-300j)","jurisdiction":"USA","citation":"42 U.S.C. 300f-300j","id":"src_e465851e"},{"id":"iarc_100c","type":"regulatory","title":"IARC Monographs Volume 100C: Arsenic and Arsenic Compounds","year":2012,"inherited_from_compound":"hq-c-ino-000002"},{"id":"epa_arsenic_iris","type":"regulatory","title":"US EPA IRIS Assessment: Arsenic, Inorganic","year":1998,"inherited_from_compound":"hq-c-ino-000002"},{"id":"nrc_uranium_factsheet","type":"regulatory","title":"US NRC: Uranium Fact Sheet — Natural Isotopic Composition, Depleted Uranium Military Use, Chemical Nephrotoxicity (Proximal Tubule), Long Alpha-Emitter Half-Life (Low Specific Activity), EPA MCL 30 μg/L, Uranium Miner Radon Lung Cancer Studies (2020)","year":2020,"inherited_from_compound":"hq-c-ino-000040"},{"id":"atsdr_uranium_toxicological_profile","type":"regulatory","title":"ATSDR: Toxicological Profile for Uranium — Renal Proximal Tubule Damage, Pediatric GI Absorption (2-4× Adults), Depleted Uranium Veterans Studies, Western US Groundwater Geology, Gulf War DU Exposure Assessment, and EPA MCL Basis (2013)","year":2013,"inherited_from_compound":"hq-c-ino-000040"},{"type":"regulatory","title":"US Environmental Protection Agency (EPA)","jurisdiction":"USA","id":"src_defdd418","extraction":"description_reference"}],"meta":{"schema_version":"4.0.0","last_updated":"2026-03-25","timestamp":"2026-05-14T01:26:27.515Z"}}