{"data":{"id":"us/40-cfr-143.3","jurisdiction":"us","citation":"40 CFR 143.3","heading":"Secondary maximum contaminant levels.","body":"The secondary maximum contaminant levels for public water systems are as follows:\nContaminant Level\nAluminum 0.05 to 0.2 mg/l.\nChloride 250 mg/l.\nColor 15 color units.\nCopper 1.0 mg/l.\nCorrosivity Non-corrosive.\nFluoride 2.0 mg/l.\nFoaming agents 0.5 mg/l.\nIron 0.3 mg/l.\nManganese 0.05 mg/l.\nOdor 3 threshold odor number.\npH 6.5-8.5.\nSilver 0.1 mg/l.\nSulfate 250 mg/l.\nTotal dissolved solids (TDS) 500 mg/l.\nZinc 5 mg/l.\nThese levels represent reasonable goals for drinking water quality. The States may establish higher or lower levels which may be appropriate dependent upon local conditions such as unavailability of alternate source waters or other compelling factors, provided that public health and welfare are not adversely affected.","path":["Title 40—Protection of Environment","CHAPTER I—ENVIRONMENTAL PROTECTION AGENCY","SUBCHAPTER D—WATER PROGRAMS","PART 143—OTHER SAFE DRINKING WATER ACT REGULATIONS","Subpart A—National Secondary Drinking Water Regulations"],"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":"cbf08a271fbb2109646926923bf140264a0122b450b81d180a90282679381e23","source_id":"us-cfr","stale":true,"prev":"us/40-cfr-143.2","next":"us/40-cfr-143.4"},"notice":"GroundRules: Original legal text. Not legal advice."}