{"query":{"parameter":"methyl tert butyl ether","place":"US-CA","medium":null,"statistic":null,"kind":null},"searched":{"places":["US-CA","US"],"parameter_keys":["cas:1634-04-4","name:methyl-tert-butyl ether","name:methyl tertiary-butyl ether"],"names_matched":[["methyl tert butyl ether","cas:1634-04-4"],["methyl tert butyl ether","name:methyl-tert-butyl ether"],["methyl tertiary butyl ether mtbe","name:methyl tertiary-butyl ether","mtbe"],["mtbe","name:methyl tertiary-butyl ether","mtbe"],["methyl tertiary butyl ether","name:methyl tertiary-butyl ether","methyl tertiary butyl ether"]],"match":"exact+contains","order":"The place's own instruments first, then each place above it, each in its register's order"},"total":8,"offset":0,"returned":8,"next_offset":null,"rows":[{"id":"8b2e217d342ee327","parameter":"Methyl tertiary butyl ether (MTBE)","value":"5.0E+00","value_num":5,"unit":"µg/L","direction":"max","kind":"guideline","medium":"groundwater","level":"regional","parameter_key":"cas:1634-04-4","place":["US-CA"],"conditions":["Tier 1 ESLs: one level per chemical and medium for a generic site (residential land use, groundwater a drinking-water resource, shallow soil); a screening level is not a cleanup standard"],"cite":{"instrument":"us_ca_esl_groundwater","title":"California, San Francisco Bay RWQCB — Environmental Screening Levels (ESLs), Tier 1, 2025 (Rev. 4) — groundwater","issuer":"San Francisco Bay Regional Water Quality Control Board","edition":"2025 (Rev. 4)","source_url":"https://www.waterboards.ca.gov/sanfranciscobay/water_issues/programs/ESL/ESL_Summary_Tables_Rev4.pdf","source_sha256":null,"fetched_at":"2026-09-30","source_status":{"checked":"2026-10-15","status":"not verified"},"section":null,"page":null,"quote":null,"table":"eau","column":"tier1"}},{"id":"0d0dda594f3bb424","parameter":"Methyl tertiary butyl ether (MTBE)","value":"2.8E-02","value_num":0.028,"unit":"mg/kg","direction":"max","kind":"guideline","medium":"soil","level":"regional","parameter_key":"cas:1634-04-4","place":["US-CA"],"conditions":["Tier 1 ESLs: one level per chemical and medium for a generic site (residential land use, groundwater a drinking-water resource, shallow soil); a screening level is not a cleanup standard"],"cite":{"instrument":"us_ca_esl_soil","title":"California, San Francisco Bay RWQCB — Environmental Screening Levels (ESLs), Tier 1, 2025 (Rev. 4) — soil","issuer":"San Francisco Bay Regional Water Quality Control Board","edition":"2025 (Rev. 4)","source_url":"https://www.waterboards.ca.gov/sanfranciscobay/water_issues/programs/ESL/ESL_Summary_Tables_Rev4.pdf","source_sha256":null,"fetched_at":"2026-09-30","source_status":{"checked":"2026-10-15","status":"not verified"},"section":null,"page":null,"quote":null,"table":"sols","column":"tier1"}},{"id":"e5d17ebe9d89e94a","parameter":"Methyl-tert-butyl ether","value":"0.013","value_num":0.013,"unit":"mg/L","direction":"max","kind":"limit","medium":"drinking_water","level":"regional","parameter_key":"name:methyl-tert-butyl ether","place":["US-CA"],"conditions":["The MCLs for the primary drinking water chemicals shown in table 64444–A shall not be exceeded in the water supplied to the public."],"cite":{"instrument":"us_ca_title22_mcl","title":"California Code of Regulations, Title 22 — drinking water maximum contaminant levels: Tables 64431–A (inorganic), 64442 and 64443 (radionuclides), 64444–A (organic), 64449–A and 64449–B (secondary) and 64533–A (disinfection byproducts)","issuer":"State of California, State Water Resources Control Board (Division of Drinking Water)","edition":"California Regulations Related to Drinking Water, September 2026 (the State Water Board's compilation of Titles 17 and 22; it follows the August 2025 compilation), as served 2026-10-15","source_url":"https://www.waterboards.ca.gov/drinking_water/certlic/drinkingwater/documents/lawbook/drinking-water-regulations.pdf","source_sha256":"db6df322bf1507b6e098a10faf84284b99cba21a48a1832960d9b0b6bd1478bb","fetched_at":"2026-10-15","source_status":{"checked":"2026-10-15","status":"not verified"},"section":"22 CCR § 64444, Table 64444–A, Maximum Contaminant Levels, Organic Chemicals, (a) Volatile Organic Chemicals (VOCs)","page":113,"quote":"Methyl-tert-butyl ether ...................................................................................... 0 . 0 1 3"}},{"id":"71bbf20fadc8b779","parameter":"Methyl-tert-butyl ether (MTBE)","value":"0.005","value_num":0.005,"unit":"mg/L","direction":"max","kind":"limit","medium":"drinking_water","level":"regional","parameter_key":"name:methyl-tert-butyl ether","place":["US-CA"],"conditions":["(a) The secondary MCLs shown in Tables 64449–A and 64449–B shall not be exceeded in the water supplied to the public by community water systems."],"cite":{"instrument":"us_ca_title22_mcl","title":"California Code of Regulations, Title 22 — drinking water maximum contaminant levels: Tables 64431–A (inorganic), 64442 and 64443 (radionuclides), 64444–A (organic), 64449–A and 64449–B (secondary) and 64533–A (disinfection byproducts)","issuer":"State of California, State Water Resources Control Board (Division of Drinking Water)","edition":"California Regulations Related to Drinking Water, September 2026 (the State Water Board's compilation of Titles 17 and 22; 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SSL values are based on DAF=1"],"cite":{"instrument":"us_rsl_soil","title":"US EPA — Regional Screening Levels (RSLs), Summary Table (TR=1E-06, THQ=1.0), November 2024 — Soil","issuer":"U.S. Environmental Protection Agency (EPA)","edition":"November 2024","source_url":"https://semspub.epa.gov/src/document/HQ/405270","source_sha256":"0160dc81b4f55d738a354a74de92488f149946ebfa7c6a6c64592f45348043d7","fetched_at":"2026-09-19","source_status":{"checked":"2026-10-15","status":"not verified"},"section":null,"page":null,"quote":null,"table":"ssl","column":"risque"}},{"id":"d71ab8eb5fab244b","parameter":"Methyl tert-Butyl Ether (MTBE)","value":"14","value_num":14,"unit":"µg/L","direction":"max","kind":"guideline","medium":"drinking_water","level":"national","parameter_key":"cas:1634-04-4","place":["US"],"conditions":["Tap Water (ug/L): Regional Screening Level (RSL) Summary Table (TR=1E-06, HQ=1) November 2024"],"cite":{"instrument":"us_rsl_tapwater","title":"US EPA — Regional Screening Levels (RSLs), Summary Table (TR=1E-06, THQ=1.0), November 2024 — Tap Water","issuer":"U.S. Environmental Protection Agency (EPA)","edition":"November 2024","source_url":"https://semspub.epa.gov/src/document/HQ/405270","source_sha256":"0160dc81b4f55d738a354a74de92488f149946ebfa7c6a6c64592f45348043d7","fetched_at":"2026-09-19","source_status":{"checked":"2026-10-15","status":"not verified"},"section":null,"page":null,"quote":null,"table":"eau","column":"eau_robinet"}}],"next":[{"tool":"check_values","says":"Has your user measured this? check_values sets each of their results beside every row held here, with a verdict and the row's cite.","arguments":{"place":"US-CA"},"needs":{"rows":"Your user's measured results, as their table prints them: [{parameter: \"methyl tert butyl ether\", value, unit}, ...], any other parameters too."},"post":"/api/v1/check"},{"tool":"read_certificate","says":"Has your user a laboratory certificate? read_certificate reads every row it prints, each with its page, and checks them against these limits.","arguments":{"place":"US-CA"},"needs":{"content_base64":"The laboratory's certificate (PDF) or its XLSX, XLS or CSV export, as base64; or file_url, a public https address of it."},"post":"/api/v1/certificate"}]}