{"data":{"id":"us/40-cfr-141.51","jurisdiction":"us","citation":"40 CFR 141.51","heading":"Maximum contaminant level goals for inorganic contaminants.","body":"(a) [Reserved]\n(b) MCLGs for the following contaminants are as indicated:\nContaminant MCLG (mg/l)\nAntimony 0.006\nArsenic zero 1\nAsbestos 7 Million fibers/liter (longer than 10 µm).\nBarium 2\nBeryllium .004\nCadmium 0.005\nChromium 0.1\nCopper 1.3\nCyanide (as free Cyanide) .2\nFluoride 4.0\nLead zero\nMercury 0.002\nNitrate 10 (as Nitrogen).\nNitrite 1 (as Nitrogen).\nTotal Nitrate + Nitrite 10 (as Nitrogen).\nSelenium 0.05\nThallium .0005\n1 This value for arsenic is effective January 23, 2006. Until then, there is no MCLG.","path":["Title 40—Protection of Environment","CHAPTER I—ENVIRONMENTAL PROTECTION AGENCY","SUBCHAPTER D—WATER PROGRAMS","PART 141—NATIONAL PRIMARY DRINKING WATER REGULATIONS","Subpart F—Maximum Contaminant Level Goals and Maximum Residual Disinfectant Level Goals"],"source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-25/title-40.xml","current_through":"2026-08-25","vintage":"","retrieved_at":"2026-08-27T02:26:04Z","sha256":"9c609762bd5502cc74f20f03fb0642e015d8805317f3cdab64994d1eb906feef","source_id":"us-cfr","stale":true,"prev":"us/40-cfr-141.50","next":"us/40-cfr-141.52"},"notice":"GroundRules: Original legal text. Not legal advice."}