{"data":{"id":"us/40-cfr-437.21","jurisdiction":"us","citation":"40 CFR 437.21","heading":"Effluent limitations attainable by the application of the best practicable control technology currently available (BPT).","body":"Except as provided in 40 CFR 125.30 through 125.32 or § 437.20(b), any existing point source subject to this subpart must achieve the following effluent limitations representing the application of BPT:\nBPT Limitations\nRegulated parameter Maximum daily 1 Maximum monthly avg. 1\nConventional Parameters\nO\u0026G 127 38.0\npH (2) (2)\nTSS 74.1 30.6\nMetal Parameters\nArsenic 2.95 1.33\nCadmium 0.0172 0.0102\nChromium 0.746 0.323\nCobalt 56.4 18.8\nCopper 0.500 0.242\nLead 0.350 0.160\nMercury 0.0172 0.00647\nTin 0.335 0.165\nZinc 8.26 4.50\nOrganic Parameters\nBis(2-ethylhexyl) phthalate 0.215 0.101\nButylbenzyl phthalate 0.188 0.0887\nCarbazole 0.598 0.276\nn-Decane 0.948 0.437\nFluoranthene 0.0537 0.0268\nn-Octadecane 0.589 0.302\n1 mg/L (ppm).\n2 Within the range 6 to 9.","path":["Title 40—Protection of Environment","CHAPTER I—ENVIRONMENTAL PROTECTION AGENCY","SUBCHAPTER N—EFFLUENT GUIDELINES AND STANDARDS","PART 437—THE CENTRALIZED WASTE TREATMENT POINT SOURCE CATEGORY","Subpart B—Oils Treatment and Recovery"],"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":"0f549e908ddf67d515b363de360e25379c9ab25c969c84223409f8d04ecd9f57","source_id":"us-cfr","stale":true,"prev":"us/40-cfr-437.20","next":"us/40-cfr-437.22"},"notice":"GroundRules: Original legal text. Not legal advice."}