{"hq_id":"hq-p-wer-000104","name":"Perchlorate in Private Wells from Agricultural Fertilizer and DoD Legacy Sites (Chilean Nitrate Fertilizer, Propellant Manufacturing, Unexploded Ordnance — No Federal MCL, State-Level Variance)","category":{"primary":"wearable_specialty","secondary":"private_well_emerging_contaminant","tags":["perchlorate","ammonium perchlorate","Chilean nitrate","agricultural fertilizer","DoD propellant","unexploded ordnance","thyroid","pregnancy","private well","no federal MCL"]},"product_tier":"WER","overall_risk_level":"moderate_to_high","description":"Perchlorate (ClO4-) is a thyroid-affecting drinking-water contaminant from two primary anthropogenic sources: (1) DoD propellant manufacturing, ammunition plants, and unexploded-ordnance ranges (ammonium perchlorate is the dominant solid-rocket oxidizer); and (2) AGRICULTURAL FERTILIZER — historical Chilean-nitrate (caliche-ore) deposits naturally contain 0.03-0.7% perchlorate, and US imports of Chilean nitrate from 1850-2000 distributed perchlorate broadly across agricultural watersheds. The 2020 EPA regulatory determination NOT TO REGULATE perchlorate at the federal level reversed an earlier 2011 finding that occurrence and risk thresholds were met; EPA reconsideration was reopened in 2023 with no current MCL. Massachusetts maintains a 2 ug/L state MCL; California 6 ug/L; other states variable. CCL5 (2022) lists perchlorate. The mechanism of toxicity is COMPETITIVE INHIBITION OF THE THYROID SODIUM/IODIDE SYMPORTER (NIS) — perchlorate blocks iodide uptake and reduces thyroid hormone synthesis. Pregnant individuals (especially with marginal iodine intake, ~30% of US women), infants, and bottle-fed neonates are the highest-risk population because thyroid-hormone availability during pregnancy and early infancy is critical for neurodevelopment. Private wells in agricultural / former-Chilean-nitrate-receiving regions and within DoD-cleanup-site impact zones (Henderson NV, Edwards AFB CA, Camp Edwards MA) are the dominant private-well exposure context. Perchlorate is highly water-soluble, environmentally persistent, and not readily removed by conventional carbon or RO; ion-exchange (chloride-form anion resin) is the standard removal technology.","synthesis":{"derived_risk_level":"moderate_to_high","synthesis_confidence":0.66,"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":4,"compounds_total":4,"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":"pregnant individuals (especially iodine-marginal), infants, neonates on bottle-fed formula, individuals with thyroid disease, agricultural-watershed and DoD-legacy-site residents","overall_risk":"moderate_to_high","primary_concerns":["Federal MCL absence — 2020 EPA reversal of 2011 determination; reconsideration ongoing","Thyroid sodium/iodide symporter inhibition reduces hormone synthesis","Pregnancy + early infancy neurodevelopmental window most vulnerable","Chilean-nitrate-fertilizer-impacted agricultural watersheds are a diffuse source","Conventional carbon + RO partial; ion-exchange specialty resin is the standard removal"],"exposure_routes":"Oral ingestion of contaminated drinking water and infant formula reconstituted with same"},"exposure":{"routes":["oral"],"contact_types":["oral_drinking","oral_infant_formula"],"users":["adult","infant","child","pregnant"],"duration":"chronic","frequency":"daily","scenarios":["Private well in former Chilean-nitrate fertilizer-receiving agricultural region","Private well within DoD propellant-manufacturing or UXO site impact zone","Bottle-fed neonate on perchlorate-contaminated formula reconstitution water","Pregnant individual with marginal iodine intake on perchlorate-impacted well","Co-occurring high-nitrate well in agricultural region — combined thyroid + methemoglobinemia concern"],"notes":"EPA 2011 final determination: perchlorate occurrence + risk thresholds met. EPA 2020 regulatory determination: REVERSED — no MCL. EPA 2023 reconsideration: in progress. CCL5 (2022) lists perchlorate. State MCLs: MA 2 ug/L; CA 6 ug/L; others variable. DoD legacy sites: Henderson NV (Kerr-McGee), Edwards AFB CA, Camp Edwards MA, Aerojet Sacramento CA. Chilean-nitrate (caliche ore) NaNO3 with 0.03-0.7% NaClO4 co-impurity. Mechanism: competitive inhibition of NIS thyroid iodide-uptake; blocks T3/T4 synthesis. Reference dose: NRC 2005 RfD 0.7 ug/kg/d (thyroid endpoint). Pregnant + infant + iodine-marginal populations are highest risk. Removal: ion-exchange chloride-form anion resin (single-pass); RO partial; GAC ineffective. NSF/ANSI 58 partial credit; specialty perchlorate-rated IX is the standard."},"consumer_guidance":{"usage_warning":"If your private well is in a DoD-legacy impact zone (Henderson NV, Edwards AFB CA, Camp Edwards MA, Aerojet Sacramento CA, or any site identified by EPA / DoD perchlorate-cleanup framework), or in a former-Chilean-nitrate agricultural-watershed region, or in a state with a state-level perchlorate MCL (MA 2 ug/L, CA 6 ug/L), test for perchlorate using EPA Method 314.0 or 332.0. Pregnant + nursing + bottle-fed-infant cohorts are the priority. Verify iodine-sufficiency via prenatal vitamin (iodized salt + 150 ug iodine prenatal supplement is the standard recommendation). Removal is NOT achieved by standard activated-carbon or basic RO systems — install a perchlorate-rated chloride-form anion-exchange system if detected. State-level guidance + advocacy organizations track this issue actively.","safer_alternatives":["Perchlorate-rated chloride-form anion-exchange point-of-use system","Specialty RO system with perchlorate-claim NSF certification (newer generation)","Bottled water for pregnant and bottle-fed-infant cohorts (interim)","Iodine-sufficiency prenatal supplementation (150 ug daily)","Connection to a certified public water system if accessible"]},"regulatory":{"applicable_regulations":[{"jurisdiction":"USA","regulation":"EPA perchlorate regulatory determination (2020 reversal; 2023 reconsideration)","citation":"85 FR 43990 (2020 determination not to regulate); EPA 2023 reconsideration in progress","requirements":"EPA 2011 final determination FOUND occurrence threshold met for perchlorate regulation; 2020 reversed (no MCL); 2023 reconsideration underway. CCL5 includes perchlorate. Massachusetts (2 ug/L) and California (6 ug/L) maintain state MCLs.","compliance_status":null,"effective_date":null,"enforcing_agency":"EPA / state primacy","penalties":null,"source_ref":null},{"jurisdiction":"USA","regulation":"FDA — perchlorate in food + bottled water","citation":"FDA Total Diet Study; bottled water 21 CFR 165.110(b)(13)(i) — references EPA contaminant table","requirements":"FDA monitors perchlorate in food via Total Diet Study. Bottled water cross-references EPA standards (currently no federal MCL). FDA approved indirect-food-additive use of perchlorate-containing antistatic agent — withdrew approval 2017 for some uses.","compliance_status":null,"effective_date":null,"enforcing_agency":"FDA","penalties":null,"source_ref":null},{"jurisdiction":"USA -- DoD legacy","regulation":"DoD/EPA perchlorate-impacted site cleanup framework","citation":"DoD Memorandum 2003 + 2006 + 2010; CERCLA cleanup authority","requirements":"Perchlorate is a legacy contaminant at DoD propellant-manufacturing sites, ammunition plants, and unexploded-ordnance ranges. Cleanup proceeds under CERCLA / state programs; agricultural-fertilizer (Chilean nitrate) use is a separate diffuse source.","compliance_status":null,"effective_date":null,"enforcing_agency":"DoD / EPA","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 perchlorate-loaded ion-exchange resin: vendor take-back to specialty regeneration / disposal; in-place chemical regeneration generates concentrated brine that requires specialty handling. RO concentrate: state-approved discharge.","hazardous_waste":true,"expected_lifespan":"perchlorate-rated IX resin 6-12 months / 1,000 gallons; RO membrane 1-3 yr"},"formulation":{"form":"varies","key_ingredients":[],"certifications":[]},"materials":{"common":[],"concerning":[],"preferred":[]},"compound_composition":[{"hq_id":"hq-c-org-001436","compound_name":null,"role":"primary_contaminant","typical_concentration":"perchlorate (ClO4-) ion; EPA CCL5 listed; MA state MCL 2 ug/L; CA state MCL 6 ug/L"},{"hq_id":"hq-c-org-000449","compound_name":null,"role":"ammonium_salt_form","typical_concentration":"ammonium perchlorate — DoD solid-rocket oxidizer; primary propellant-manufacturing-source contaminant"},{"hq_id":"hq-c-ino-000153","compound_name":null,"role":"co_contaminant","typical_concentration":"nitrate often co-occurs in Chilean-nitrate-impacted wells; EPA MCL 10 mg/L NO3-N"},{"hq_id":"hq-c-ino-000079","compound_name":null,"role":"fertilizer_co_constituent","typical_concentration":"sodium nitrate — Chilean-nitrate fertilizer matrix; perchlorate co-impurity 0.03-0.7%"}],"identifiers":{"common_names":["perchlorate in private wells from agricultural fertilizer and dod legacy sites (chilean nitrate fertilizer, propellant manufacturing, unexploded ordnance — no federal mcl, state-level variance)"],"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":"2026-06-28T20:27:02.919Z"},"_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"}