{"data":{"id":"us/40-cfr-421.126","jurisdiction":"us","citation":"40 CFR 421.126","heading":"Pretreatment standards for new sources.","body":"Except as provided in 40 CFR 403.7, any new source subject to this subpart which introduces pollutants into a publicly owned treatment works must comply with 40 CFR part 403 and achieve the following pretreatment standards for new sources. The mass of wastewater pollutants in secondary silver process wastewater introduced into a POTW shall not exceed the following values:\n(a) Subpart L—Film Stripping.\nPSNS\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/troy ounce of silver from film stripping\nCopper 64.450 30.720\nZinc 51.360 21.150\nAmmonia (as N) 6,712.000 2,951.000\n(b) Subpart L—Film Stripping Wet Air Pollution Control and Precipitation and Filtration of Film Stripping Solutions Wet Air Pollution Control.\nPSNS\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/troy ounce of silver from precipitation and filtration of film stripping solutions\nCopper 1.242 .592\nZinc .990 .408\nAmmonia (as N) 129.300 56.840\n(c) Subpart L—Precipitation and Filtration of Film Stripping Solutions.\nPSNS\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/troy ounce of silver precipitated\nCopper 73.690 35.120\nZinc 58.720 24.180\nAmmonia (as N) 7,674.000 3,374.000\n(d) Subpart L—Precipitation and Filtration of Photographic Solutions.\nPSNS\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/troy ounce of silver precipitated\nCopper 34.048 16.226\nZinc 27.132 11.172\nAmmonia (as N) 3,545.000 1,559.000\n(e) Subpart L—Precipitation and Filtration of Photographic Solutions Wet Air Pollution Control.\nPSNS\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/troy ounce of silver from precipitation and filtration of photographic solutions\nCopper 15.540 7.406\nZinc 12.380 5.099\nAmmonia (as N) 1,618.000 711.400\n(f) Subpart L—Electrolytic Refining.\nPSNS\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/troy ounce of silver from electrolytic refining\nCopper .973 .464\nZinc .775 .319\nAmmonia (as N) 101.300 44.540\n(g) Subpart L—Furnace Wet Air Pollution Control.\nPSNS\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/troy ounce of silver roasted, smelted or dried\nCopper .000 .000\nZinc .000 .000\nAmmonia (as N) .000 .000\n(h) Subpart L—Leaching.\nPSNS\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/troy ounce of silver produced from leaching\nCopper .110 .053\nZinc .088 .036\nAmmonia (as N) 11.470 5.040\n(i) Subpart L—Leaching Wet Air Pollution Control and Precipitation of Nonphotographic Solutions Wet Air Pollution Control.\nPSNS\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/troy ounce of silver produced from leaching or silver precipitated\nCopper 5.671 2.703\nZinc 4.519 1.861\nAmmonia (as N) 590.500 259.600\n(j) Subpart L—Precipitation and Filtration of Nonphotographic Solutions.\nPSNS\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/troy ounce of silver precipitated\nCopper 3.930 1.873\nZinc 3.132 1.290\nAmmonia (as N) 409.300 179.900\n(k) Subpart L—Floor and Equipment Washdown.\nPSNS\nPollutant or pollutant property Maximum for any 1 day Maximum for monthly average\nmg/troy ounce of silver production\nCopper .000 .000\nZinc .000 .000\nAmmonia (as N) .000 .000","path":["Title 40—Protection of Environment","CHAPTER I—ENVIRONMENTAL PROTECTION AGENCY","SUBCHAPTER N—EFFLUENT GUIDELINES AND STANDARDS","PART 421—NONFERROUS METALS MANUFACTURING POINT SOURCE CATEGORY","Subpart L—Secondary Silver Subcategory"],"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":"b2b16290f7aa98694180640194f27ce8bc5ab4edc3ec6866cf8c90347cfd9f72","source_id":"us-cfr","stale":true,"prev":"us/40-cfr-421.125","next":"us/40-cfr-421.127"},"notice":"GroundRules: Original legal text. Not legal advice."}