{"hq_id":"hq-p-wer-000095","name":"Iron Bacteria Biofilm in Domestic Wells (Gallionella, Leptothrix, Sulfate-Reducing Bacteria — H2S, Manganese Co-Contamination, Slime, Plumbing Biofouling)","category":{"primary":"wearable_specialty","secondary":"private_well_water","tags":["iron bacteria","Gallionella","Leptothrix","biofilm","sulfate-reducing bacteria","hydrogen sulfide","manganese","well water","plumbing biofouling","rotten egg odor"]},"product_tier":"WER","overall_risk_level":"moderate","description":"Iron-bacteria biofilms in private domestic wells are a slime-forming microbial consortium dominated by chemolithotrophic Gallionella ferruginea (stalked, twisted-stalk morphology), Leptothrix ochracea (sheathed), and ribbon-form Crenothrix species. They oxidize ferrous (Fe2+) to ferric (Fe3+) iron, producing the characteristic reddish-brown to orange gelatinous slime that clogs well screens, pump impellers, pressure tanks, and fixture aerators. They are NOT pathogens themselves but they create anoxic micro-environments that harbor sulfate-reducing bacteria (Desulfovibrio, Desulfotomaculum), which in turn produce hydrogen sulfide (H2S) — the rotten-egg odor signal. Manganese-cycling bacteria (Hyphomicrobium, Pedomicrobium) often co-occur, depositing black manganese oxide crusts that compound the iron biofilm. The exposure pattern is consumer-water aesthetic and infrastructure damage rather than acute toxicity, but the secondary drinking-water guidelines (Fe 0.3 mg/L, Mn 0.05 mg/L, sulfate 250 mg/L) are routinely exceeded in affected wells. Manganese has emerged as a neurodevelopmental concern at concentrations far below the iron-staining threshold (Health Canada 0.12 mg/L MAC 2019; WHO provisional guideline value 0.4 mg/L); H2S at >2 mg/L causes nausea and is a documented occupational hazard during well-pit entry. Treatment is shock-chlorination, biofilm physical removal, and continuous chlorination or aeration — all of which introduce their own chemistry. Private wells are EXCLUDED from EPA SDWA enforcement; owner is the regulator.","synthesis":{"derived_risk_level":"moderate","synthesis_confidence":0.569,"synthesis_method":"compound_composition","context_used":"human_infant","context_source":"product_users","exposure_modifier":1.15,"vulnerability_escalated":true,"escalation_reason":"Infant exposure group","compounds_resolved":5,"compounds_total":5,"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 (manganese neurodevelopmental sensitivity), well drillers / pit-entry workers (H2S confined-space), households with reactive airway disease (chlorination off-gassing)","overall_risk":"moderate","primary_concerns":["Manganese neurodevelopmental signal at infant-formula reconstitution exposures","Hydrogen sulfide volatilizes from heated water — shower inhalation pathway","Confined-space H2S hazard during well-pit / pump-house service","Shock-chlorination disinfection-byproduct (DBP) formation in iron-rich water","Aesthetic and infrastructure damage compounds owner reluctance to test rigorously"],"exposure_routes":"Oral (drinking, formula), inhalation (H2S in showers + pit entry), dermal (bathing)"},"exposure":{"routes":["oral","inhalation","dermal"],"contact_types":["oral_drinking","inhalation_h2s","dermal_bathing"],"users":["adult","infant","child","pet_dog","pet_cat"],"duration":"chronic","frequency":"daily","scenarios":["Daily drinking from a private well with reddish-brown staining and 0.3+ mg/L iron","Hot-shower H2S inhalation — sulfide volatilizes preferentially in heated water","Infant formula reconstituted with high-manganese well water — neurodevelopmental concern","Well-pit entry by homeowner / well driller — acute H2S occupational exposure","Shock-chlorination treatment overshoot — chlorine taste/odor + DBP formation"],"notes":"Gallionella ferruginea: stalked iron-oxidizing bacterium; Leptothrix ochracea: sheathed; Crenothrix polyspora: ribbon. Sulfate-reducing bacteria (SRB) Desulfovibrio + Desulfotomaculum produce H2S in anoxic biofilm pockets. Health Canada manganese MAC revised from no-value to 0.12 mg/L in 2019 citing neurodevelopmental signal at infant-formula reconstitution exposures. EPA secondary (non-enforceable) limits: Fe 0.3, Mn 0.05, sulfate 250 mg/L. WHO 2021 provisional manganese guideline 0.4 mg/L. Private wells: EPA SDWA exempt — owner manages testing and treatment. Biofilm shock-chlorination protocols: ANSI/NSF Standard 60 chlorine; 100-200 mg/L free chlorine, 12-hour contact, full system flush. H2S occupational: OSHA PEL 20 ppm ceiling; IDLH 100 ppm; well-pit confined-space entry hazard."},"consumer_guidance":{"usage_warning":"Test private wells annually for total iron, manganese, hydrogen sulfide, sulfate, and total coliform; add a one-time deeper panel covering arsenic, nitrate, lead, and uranium where geology suggests elevated risk. If iron staining or rotten-egg odor is present, do NOT use the water for infant-formula reconstitution until manganese is quantified — Health Canada 0.12 mg/L MAC drives the conservative exposure ceiling. Shock-chlorinate following NSF-60 protocols; flush thoroughly before resumption of drinking-water use to clear DBP residuals. Never enter a well pit without confined-space ventilation and a calibrated H2S monitor (alarm 10 ppm).","safer_alternatives":["Continuous chlorination + greensand-plus or birm-media iron filtration","Aeration + manganese oxidation tower (no chemical addition)","Reverse-osmosis point-of-use system for drinking + cooking water (after pre-treatment)","Bottled water for infant-formula reconstitution if manganese >0.1 mg/L is documented","Annual third-party laboratory testing — state-certified labs preferred"]},"regulatory":{"applicable_regulations":[{"jurisdiction":"USA","regulation":"EPA Safe Drinking Water Act (SDWA) — public-water-system scope","citation":"42 U.S.C. 300f; 40 CFR Parts 141-143","requirements":"SDWA primary and secondary MCLs apply to public water systems serving >=15 connections / >=25 persons. Private domestic wells are EXCLUDED — owner is the regulator. EPA recommends annual testing for coliforms, nitrate, TDS; 3-5 yr testing for additional analytes.","compliance_status":null,"effective_date":null,"enforcing_agency":"EPA / state primacy","penalties":null,"source_ref":null},{"jurisdiction":"USA","regulation":"USGS National Water Quality Assessment (NAWQA) reference data","citation":"USGS Circular 1360 (private wells); NAWQA principal-aquifer surveys","requirements":"USGS publishes principal-aquifer occurrence statistics for arsenic, radium, nitrate, VOCs in private wells. Used as state-level prioritization but carries no regulatory force.","compliance_status":null,"effective_date":null,"enforcing_agency":"USGS","penalties":null,"source_ref":null},{"jurisdiction":"USA -- state level","regulation":"State private-well construction + testing rules","citation":"Varies; e.g., NJ Private Well Testing Act 2002, NH RSA 485-C","requirements":"Some states mandate private-well testing at point of real-estate transfer (NJ, NH, OR partial). Most states do not require any testing of operating wells.","compliance_status":null,"effective_date":null,"enforcing_agency":"State env/health 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":"Spent filtration media (greensand, birm, manganese-greensand): handled per state solid-waste rules; iron/manganese precipitates are not RCRA-hazardous unless co-deposited with arsenic, in which case TCLP testing applies.","hazardous_waste":false,"expected_lifespan":"filtration media 1-3 yr; chlorine injection pump 5-10 yr; well-itself 30+ yr"},"formulation":{"form":"varies","key_ingredients":[],"certifications":[]},"materials":{"common":[],"concerning":[],"preferred":[]},"compound_composition":[{"hq_id":"hq-c-org-000645","compound_name":null,"role":"iron_oxide_deposit","typical_concentration":"iron oxide / oxyhydroxide deposits — Fe2O3, FeO(OH); 0.3-30 mg/L total iron in affected wells"},{"hq_id":"hq-c-ino-000023","compound_name":null,"role":"co_contaminant","typical_concentration":"manganese 0.05-2.0 mg/L; secondary MCL 0.05 mg/L; Health Canada MAC 0.12 mg/L (2019)"},{"hq_id":"hq-c-ino-000014","compound_name":null,"role":"biological_byproduct","typical_concentration":"hydrogen sulfide 0.1-10 mg/L from sulfate-reducing bacterial activity within biofilm"},{"hq_id":"hq-c-ino-000097","compound_name":null,"role":"co_deposit","typical_concentration":"manganese oxide black crust — MnO2 deposits from Mn-cycling bacteria"},{"hq_id":"hq-c-org-000055","compound_name":null,"role":"treatment_chemical","typical_concentration":"sodium hypochlorite shock-chlorination 100-200 mg/L for biofilm disruption"}],"identifiers":{"common_names":["iron bacteria biofilm in domestic wells (gallionella, leptothrix, sulfate-reducing bacteria — h2s, manganese co-contamination, slime, plumbing biofouling)"],"aliases":[],"manufacturer":null,"brands":[]},"brand_examples":[],"brand_examples_disclaimer":null,"sources":[{"type":"expert_curation","name":"ALETHEIA Safety Database","date":"2026-05-08"}],"meta":{"schema_version":"4.0.0","last_updated":"2026-05-08","timestamp":"2026-06-28T20:23:59.493Z"},"_notice":"ALETHEIA output is reference data, not professional advice. Not a substitute for primary agency sources or qualified professionals. See https://aletheia.holisticquality.io/disclaimer.","_disclaimer_url":"https://aletheia.holisticquality.io/disclaimer"}