{"query":{"parameter":"silver","place":"US-OK","medium":null,"statistic":null,"kind":null},"searched":{"places":["US-OK","US"],"parameter_keys":["cas:7440-22-4","cas:93-72-1","cas:506-61-6","name:silver-108m","name:silver-110m","name:silver-111","cas:506-64-9","name:silver - total","name:silver, total","name:silver, total recoverable","name:total silver"],"names_matched":[["silver","cas:7440-22-4"],["2 4 5 tp silver","cas:93-72-1"],["potassium silver cyanide","cas:506-61-6"],["silver 108m","name:silver-108m"],["silver 110m","name:silver-110m"],["silver 111","name:silver-111"],["silver cyanide","cas:506-64-9"],["silver cyanide ag cn","cas:506-64-9"],["silver total","name:silver - total"],["silver total","name:silver, total"],["silver total recoverable","name:silver, total recoverable"],["total silver","name:total silver"],["total silver freshwater","name:total silver"],["total silver marine","name:total silver"],["plata total","name:total silver","plata"]],"match":"exact+contains","order":"The place's own instruments first, then each place above it, each in its register's order; rows for a marine receiving water after the rest, as none of the place's own rows names a marine, salt, estuarine, coastal or ocean water","not_sent":{"rows":12,"names":["Trichlorophenoxypropionic acid, -2,4,5","Chlorophenoxy Herbicide (2,4,5-TP) [Silvex]","Silvex/2,4,5-TP","2,4,5-TP (Silvex)","2-4-5-TP Silvex"],"says":"12 rows share a parameter key with a longer name holding \"silver\" but are printed under names without these words (that key is wider than the name): not sent. Ask for one by its name or CAS number."}},"total":450,"offset":0,"returned":50,"next_offset":50,"rows":[{"id":"03b61b821b9913fd","parameter":"Silver (Dissolved)","value":"e(1.72[ln(hardness)]-6.59)*0.85","unit":"µg/L","statistic":"instant","direction":"max","kind":"guideline","medium":"surface_water","level":"regional","parameter_key":"cas:7440-22-4","place":["US-OK"],"conditions":["receiving_water is freshwater","waters designated with any Fish and Wildlife Propagation subcategory (a water's designated uses: Appendix A; not evaluated)","hardness-dependent: the printed equation of the receiving water's hardness; not evaluated"],"cite":{"instrument":"us_ok_wqs","title":"Oklahoma's Water Quality Standards (OAC 252:730): Appendix G Tables 1-2 numerical criteria by beneficial use, and the numerical criteria of 252:730-5-10, 5-12 and 5-19, and Appendix F chloride, sulfate and TDS by WQM segment (252:730-5-13)","issuer":"State of Oklahoma, Department of Environmental Quality (Environmental Quality Board)","edition":"OAC 252:730 as DEQ codifies it (Board adoption February 17, 2023, effective September 15, 2023; DEQ's own PDF, born-digital). US EPA's posting in effect for CWA purposes (effective December 18, 2024, cover February 10, 2025) is an OCR'd scan of the later edition; its Appendix G carries no amendment after September 15, 2023. EPA's exceptions are honoured: the perchlorate 'fish consumption and water' 9 µg/L (no action) and the Livestock Agriculture subcategory (disapproved) are not held; Appendix E site-specific criteria for Poteau and Idabel are not held. Appendix F (amended effective 9-15-24 in EPA's posting) prints the same values as DEQ's 2023 PDF; its eight-digit sub-watershed segments (note (4)) carry EPA's no action and are not held","source_url":"https://oklahoma.gov/content/dam/ok/en/deq/documents/deqmainresources/730.pdf","source_sha256":"483572da2c80c9686956047426b41f44e56388c1ab5873c5ce38b6d905b70b40","fetched_at":"2026-10-14","source_status":{"checked":"2026-10-15","status":"unchanged"},"section":"OAC 252:730 Appendix G Table 2","page":134,"quote":"e(1.72[ln(hardness)] -6.59)*0.85 Silver (Dissolved) 7440224 50 104.8 64620.0"}},{"id":"ac12dd65e605bb07","parameter":"Silver (Dissolved)","value":"50","value_num":50,"unit":"µg/L","direction":"max","kind":"guideline","medium":"surface_water","level":"regional","parameter_key":"cas:7440-22-4","place":["US-OK"],"conditions":["receiving_water is freshwater","waters designated Public and Private Water Supply (a water's designated uses: Appendix A; not evaluated)"],"cite":{"instrument":"us_ok_wqs","title":"Oklahoma's Water Quality Standards (OAC 252:730): Appendix G Tables 1-2 numerical criteria by beneficial use, and the numerical criteria of 252:730-5-10, 5-12 and 5-19, and Appendix F chloride, sulfate and TDS by WQM segment (252:730-5-13)","issuer":"State of Oklahoma, Department of Environmental Quality (Environmental Quality Board)","edition":"OAC 252:730 as DEQ codifies it (Board adoption February 17, 2023, effective September 15, 2023; DEQ's own PDF, born-digital). US EPA's posting in effect for CWA purposes (effective December 18, 2024, cover February 10, 2025) is an OCR'd scan of the later edition; its Appendix G carries no amendment after September 15, 2023. EPA's exceptions are honoured: the perchlorate 'fish consumption and water' 9 µg/L (no action) and the Livestock Agriculture subcategory (disapproved) are not held; Appendix E site-specific criteria for Poteau and Idabel are not held. Appendix F (amended effective 9-15-24 in EPA's posting) prints the same values as DEQ's 2023 PDF; its eight-digit sub-watershed segments (note (4)) carry EPA's no action and are not held","source_url":"https://oklahoma.gov/content/dam/ok/en/deq/documents/deqmainresources/730.pdf","source_sha256":"483572da2c80c9686956047426b41f44e56388c1ab5873c5ce38b6d905b70b40","fetched_at":"2026-10-14","source_status":{"checked":"2026-10-15","status":"unchanged"},"section":"OAC 252:730 Appendix G Table 2","page":134,"quote":"e(1.72[ln(hardness)] -6.59)*0.85 Silver (Dissolved) 7440224 50 104.8 64620.0"}},{"id":"cada05e191f89915","parameter":"Silver (Dissolved)","value":"104.8","value_num":104.8,"unit":"µg/L","direction":"max","kind":"guideline","medium":"surface_water","level":"regional","parameter_key":"cas:7440-22-4","place":["US-OK"],"conditions":["receiving_water is freshwater","waters designated Public and Private Water Supply (a water's designated uses: Appendix A; not evaluated)"],"cite":{"instrument":"us_ok_wqs","title":"Oklahoma's Water Quality Standards (OAC 252:730): Appendix G Tables 1-2 numerical criteria by beneficial use, and the numerical criteria of 252:730-5-10, 5-12 and 5-19, and Appendix F chloride, sulfate and TDS by WQM segment (252:730-5-13)","issuer":"State of Oklahoma, Department of Environmental Quality (Environmental Quality Board)","edition":"OAC 252:730 as DEQ codifies it (Board adoption February 17, 2023, effective September 15, 2023; DEQ's own PDF, born-digital). US EPA's posting in effect for CWA purposes (effective December 18, 2024, cover February 10, 2025) is an OCR'd scan of the later edition; its Appendix G carries no amendment after September 15, 2023. EPA's exceptions are honoured: the perchlorate 'fish consumption and water' 9 µg/L (no action) and the Livestock Agriculture subcategory (disapproved) are not held; Appendix E site-specific criteria for Poteau and Idabel are not held. Appendix F (amended effective 9-15-24 in EPA's posting) prints the same values as DEQ's 2023 PDF; its eight-digit sub-watershed segments (note (4)) carry EPA's no action and are not held","source_url":"https://oklahoma.gov/content/dam/ok/en/deq/documents/deqmainresources/730.pdf","source_sha256":"483572da2c80c9686956047426b41f44e56388c1ab5873c5ce38b6d905b70b40","fetched_at":"2026-10-14","source_status":{"checked":"2026-10-15","status":"unchanged"},"section":"OAC 252:730 Appendix G Table 2","page":134,"quote":"e(1.72[ln(hardness)] -6.59)*0.85 Silver (Dissolved) 7440224 50 104.8 64620.0"}},{"id":"fc26fc9f07b57d61","parameter":"Silver (Dissolved)","value":"64620.0","value_num":64620,"unit":"µg/L","direction":"max","kind":"guideline","medium":"surface_water","level":"regional","parameter_key":"cas:7440-22-4","place":["US-OK"],"conditions":["receiving_water is freshwater","waters designated Warm Water Aquatic Community, Cool Water Aquatic Community or Trout Fishery (a water's designated uses: Appendix A; not evaluated)"],"cite":{"instrument":"us_ok_wqs","title":"Oklahoma's Water Quality Standards (OAC 252:730): Appendix G Tables 1-2 numerical criteria by beneficial use, and the numerical criteria of 252:730-5-10, 5-12 and 5-19, and Appendix F chloride, sulfate and TDS by WQM segment (252:730-5-13)","issuer":"State of Oklahoma, Department of Environmental Quality (Environmental Quality Board)","edition":"OAC 252:730 as DEQ codifies it (Board adoption February 17, 2023, effective September 15, 2023; DEQ's own PDF, born-digital). US EPA's posting in effect for CWA purposes (effective December 18, 2024, cover February 10, 2025) is an OCR'd scan of the later edition; its Appendix G carries no amendment after September 15, 2023. EPA's exceptions are honoured: the perchlorate 'fish consumption and water' 9 µg/L (no action) and the Livestock Agriculture subcategory (disapproved) are not held; Appendix E site-specific criteria for Poteau and Idabel are not held. Appendix F (amended effective 9-15-24 in EPA's posting) prints the same values as DEQ's 2023 PDF; its eight-digit sub-watershed segments (note (4)) carry EPA's no action and are not held","source_url":"https://oklahoma.gov/content/dam/ok/en/deq/documents/deqmainresources/730.pdf","source_sha256":"483572da2c80c9686956047426b41f44e56388c1ab5873c5ce38b6d905b70b40","fetched_at":"2026-10-14","source_status":{"checked":"2026-10-15","status":"unchanged"},"section":"OAC 252:730 Appendix G Table 2","page":134,"quote":"e(1.72[ln(hardness)] -6.59)*0.85 Silver (Dissolved) 7440224 50 104.8 64620.0"}},{"id":"fc3a9e37c51807d0","parameter":"Silver","value":"5.0","value_num":5,"unit":"mg/L","direction":"max","kind":"threshold","medium":"leachate","level":"national","parameter_key":"cas:7440-22-4","place":["US"],"conditions":["(a) A solid waste (except manufactured gas plant waste) exhibits the characteristic of toxicity if, using the Toxicity Characteristic Leaching Procedure, test Method 1311 in “Test Methods for Evaluating Solid Waste, Physical/Chemical Methods,” EPA Publication SW-846, as incorporated by reference in § 260.11 of this chapter, the extract from a representative sample of the waste contains any of the contaminants listed in table 1 at the concentration equal to or greater than the respective value given in that table. Where the waste contains less than 0.5 percent filterable solids, the waste itself, after filtering using the methodology outlined in Method 1311, is considered to be the extract for the purpose of this section."],"cite":{"instrument":"us_40cfr261_24","title":"40 CFR 261.24 — Toxicity characteristic: Table 1, maximum concentration of contaminants for the toxicity characteristic (TCLP regulatory levels)","issuer":"U.S. Environmental Protection Agency (EPA)","edition":"eCFR, 40 CFR 261.24 as of 2026-10-13 (title 40 up to date as of that day)","source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-10-13/title-40.xml?part=261&section=261.24","source_sha256":"3a1ec9b0d3051c70e471e359275657b0fa6d98e80927d2217e82b2dbbca60961","fetched_at":"2026-10-15","section":"40 CFR 261.24, Table 1","page":null,"quote":"D011 Silver 7440-22-4 5.0"}},{"id":"fd7c1002376532a0","parameter":"Silver","value":"0.43","value_num":0.43,"unit":"mg/L","statistic":"composite","direction":"max","kind":"limit","medium":"product","level":"national","parameter_key":"cas:7440-22-4","place":["US"],"conditions":["(a) Table UTS identifies the hazardous constituents, along with the nonwastewater and wastewater treatment standard levels, that are used to regulate most prohibited hazardous wastes with numerical limits. For determining compliance with treatment standards for underlying hazardous constituents as defined in § 268.2(i), these treatment standards may not be exceeded. Compliance with these treatment standards is measured by an analysis of grab samples, unless otherwise noted in the following Table UTS."],"cite":{"instrument":"us_40cfr268_48","title":"40 CFR 268.48 — Universal treatment standards: Table UTS, wastewater and nonwastewater treatment standards for the hazardous constituents of land-disposal-restricted wastes","issuer":"U.S. Environmental Protection Agency (EPA)","edition":"eCFR, 40 CFR 268.48 as of 2026-10-13 (title 40 up to date as of that day; source note: 59 FR 48103, Sept. 19, 1994, as last amended at 76 FR 34156, June 13, 2011)","source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-10-13/title-40.xml?part=268&section=268.48","source_sha256":"70b2e58a6b1e228e2c204acc69b69fab0d5a0347e35d569959073c3dc3ee4adb","fetched_at":"2026-10-15","section":"40 CFR 268.48, Table UTS, Inorganic Constituents, wastewater standard","page":null,"quote":"Silver 7440-22-4 0.43 0.14 mg/l TCLP"}},{"id":"63ff1b338ab2aea9","parameter":"Silver","value":"0.14 mg/l TCLP","value_num":0.14,"unit":"mg/L TCLP","statistic":"instant","direction":"max","kind":"limit","medium":"leachate","level":"national","parameter_key":"cas:7440-22-4","place":["US"],"conditions":["(a) Table UTS identifies the hazardous constituents, along with the nonwastewater and wastewater treatment standard levels, that are used to regulate most prohibited hazardous wastes with numerical limits. For determining compliance with treatment standards for underlying hazardous constituents as defined in § 268.2(i), these treatment standards may not be exceeded. Compliance with these treatment standards is measured by an analysis of grab samples, unless otherwise noted in the following Table UTS."],"cite":{"instrument":"us_40cfr268_48","title":"40 CFR 268.48 — Universal treatment standards: Table UTS, wastewater and nonwastewater treatment standards for the hazardous constituents of land-disposal-restricted wastes","issuer":"U.S. Environmental Protection Agency (EPA)","edition":"eCFR, 40 CFR 268.48 as of 2026-10-13 (title 40 up to date as of that day; source note: 59 FR 48103, Sept. 19, 1994, as last amended at 76 FR 34156, June 13, 2011)","source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-10-13/title-40.xml?part=268&section=268.48","source_sha256":"70b2e58a6b1e228e2c204acc69b69fab0d5a0347e35d569959073c3dc3ee4adb","fetched_at":"2026-10-15","section":"40 CFR 268.48, Table UTS, Inorganic Constituents, nonwastewater standard","page":null,"quote":"Silver 7440-22-4 0.43 0.14 mg/l TCLP"}},{"id":"d59ca9cffa240308","parameter":"Ag","value":"1.2","value_num":1.2,"unit":"mg/L","statistic":"daily_max","direction":"max","kind":"limit","medium":"water_discharge","level":"national","route":"sewer","parameter_key":"cas:7440-22-4","place":["US"],"conditions":["route is sewer","cites is 40 CFR 413","the discharge is of the Subpart B—Electroplating of Precious Metals Subcategory","existing sources (PSES)","(c) For plants discharging 38,000 liters (10,000 gal) or more per calendar day of electroplating process wastewater the following limitations shall apply:","table: Subpart B—Precious Metals Facilities Discharging 38,000 Liters or More Per Day PSES Limitations (mg/l)"],"cite":{"instrument":"us_40cfr413","title":"40 CFR Part 413 — PART 413—ELECTROPLATING POINT SOURCE CATEGORY","issuer":"U.S. Environmental Protection Agency","edition":"eCFR as of 2026-10-05","source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-10-05/title-40.xml?part=413","source_sha256":"9c6c38baf048e0e1ed5f2c05df397ea581d48822b23c4b294e52b960b2d547f9","fetched_at":"2026-10-09","source_status":{"checked":"2026-10-15","status":"unchanged"},"section":"40 CFR 413.24 (PSES)","page":null,"quote":"Ag 1.2 0.7"}},{"id":"16d95930ac34512e","parameter":"Ag","value":"0.7","value_num":0.7,"unit":"mg/L","direction":"max","kind":"limit","medium":"water_discharge","level":"national","route":"sewer","parameter_key":"cas:7440-22-4","place":["US"],"conditions":["route is sewer","cites is 40 CFR 413","the discharge is of the Subpart B—Electroplating of Precious Metals Subcategory","existing sources (PSES)","(c) For plants discharging 38,000 liters (10,000 gal) or more per calendar day of electroplating process wastewater the following limitations shall apply:","table: Subpart B—Precious Metals Facilities Discharging 38,000 Liters or More Per Day PSES Limitations (mg/l)"],"cite":{"instrument":"us_40cfr413","title":"40 CFR Part 413 — PART 413—ELECTROPLATING POINT SOURCE CATEGORY","issuer":"U.S. Environmental Protection Agency","edition":"eCFR as of 2026-10-05","source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-10-05/title-40.xml?part=413","source_sha256":"9c6c38baf048e0e1ed5f2c05df397ea581d48822b23c4b294e52b960b2d547f9","fetched_at":"2026-10-09","source_status":{"checked":"2026-10-15","status":"unchanged"},"section":"40 CFR 413.24 (PSES)","page":null,"quote":"Ag 1.2 0.7"}},{"id":"fa9ff27d054253b2","parameter":"Ag","value":"47","value_num":47,"unit":"mg/sq m-Operation","statistic":"daily_max","direction":"max","kind":"limit","medium":"water_discharge","level":"national","route":"sewer","parameter_key":"cas:7440-22-4","place":["US"],"conditions":["route is sewer","cites is 40 CFR 413","the discharge is of the Subpart B—Electroplating of Precious Metals Subcategory","existing sources (PSES)","(d) Alternatively, the following mass-based standards are equivalent to and may apply in place of those limitations specified under paragraph (c) of this section upon prior agreement between a source subject to these standards and the publicly owned treatment works receiving such regulated wastes:","table: Subpart B—Precious Metals Facilities Discharging 38,000 Liters or More Per Day PSES Limitations (mg/sq m-Operation)"],"cite":{"instrument":"us_40cfr413","title":"40 CFR Part 413 — PART 413—ELECTROPLATING POINT SOURCE CATEGORY","issuer":"U.S. Environmental Protection Agency","edition":"eCFR as of 2026-10-05","source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-10-05/title-40.xml?part=413","source_sha256":"9c6c38baf048e0e1ed5f2c05df397ea581d48822b23c4b294e52b960b2d547f9","fetched_at":"2026-10-09","source_status":{"checked":"2026-10-15","status":"unchanged"},"section":"40 CFR 413.24 (PSES)","page":null,"quote":"Ag 47 29"}},{"id":"dff57f98eaf0a460","parameter":"Ag","value":"29","value_num":29,"unit":"mg/sq m-Operation","direction":"max","kind":"limit","medium":"water_discharge","level":"national","route":"sewer","parameter_key":"cas:7440-22-4","place":["US"],"conditions":["route is sewer","cites is 40 CFR 413","the discharge is of the Subpart B—Electroplating of Precious Metals Subcategory","existing sources (PSES)","(d) Alternatively, the following mass-based standards are equivalent to and may apply in place of those limitations specified under paragraph (c) of this section upon prior agreement between a source subject to these standards and the publicly owned treatment works receiving such regulated wastes:","table: Subpart B—Precious Metals Facilities Discharging 38,000 Liters or More Per Day PSES Limitations (mg/sq m-Operation)"],"cite":{"instrument":"us_40cfr413","title":"40 CFR Part 413 — PART 413—ELECTROPLATING POINT SOURCE CATEGORY","issuer":"U.S. Environmental Protection Agency","edition":"eCFR as of 2026-10-05","source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-10-05/title-40.xml?part=413","source_sha256":"9c6c38baf048e0e1ed5f2c05df397ea581d48822b23c4b294e52b960b2d547f9","fetched_at":"2026-10-09","source_status":{"checked":"2026-10-15","status":"unchanged"},"section":"40 CFR 413.24 (PSES)","page":null,"quote":"Ag 47 29"}},{"id":"531e7c287de9c099","parameter":"Silver","value":"0.0090","value_num":0.009,"unit":"Kg/kkg (or pounds per 1,000 lb) of product","statistic":"daily_max","direction":"max","kind":"limit","medium":"water_discharge","level":"national","route":"direct","parameter_key":"cas:7440-22-4","place":["US"],"conditions":["route is direct","cites is 40 CFR 415","the discharge is of the Subpart BA—Silver Nitrate Production Subcategory","existing sources (BPT)","table: Subpart BA—Silver Nitrate"],"cite":{"instrument":"us_40cfr415","title":"40 CFR Part 415 — PART 415—INORGANIC CHEMICALS MANUFACTURING POINT SOURCE CATEGORY","issuer":"U.S. Environmental Protection Agency","edition":"eCFR as of 2026-08-01","source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-01/title-40.xml?part=415","source_sha256":"ebf67428a51e85f12785b92d537e6878c5f9838c87722ac2db82b3db673d1e23","fetched_at":"2026-09-24","source_status":{"checked":"2026-10-15","status":"unchanged"},"section":"40 CFR 415.532 (BPT)","page":null,"quote":"Silver 0.0090 0.0030"}},{"id":"bf647ccf3097a0cb","parameter":"Silver","value":"0.0030","value_num":0.003,"unit":"Kg/kkg (or pounds per 1,000 lb) of product","statistic":"monthly_avg","direction":"max","kind":"limit","medium":"water_discharge","level":"national","route":"direct","parameter_key":"cas:7440-22-4","place":["US"],"conditions":["route is direct","cites is 40 CFR 415","the discharge is of the Subpart BA—Silver Nitrate Production Subcategory","existing sources (BPT)","table: Subpart BA—Silver Nitrate"],"cite":{"instrument":"us_40cfr415","title":"40 CFR Part 415 — PART 415—INORGANIC CHEMICALS MANUFACTURING POINT SOURCE CATEGORY","issuer":"U.S. Environmental Protection Agency","edition":"eCFR as of 2026-08-01","source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-01/title-40.xml?part=415","source_sha256":"ebf67428a51e85f12785b92d537e6878c5f9838c87722ac2db82b3db673d1e23","fetched_at":"2026-09-24","source_status":{"checked":"2026-10-15","status":"unchanged"},"section":"40 CFR 415.532 (BPT)","page":null,"quote":"Silver 0.0090 0.0030"}},{"id":"f89eed0dc7b233ad","parameter":"Silver","value":"1.0","value_num":1,"unit":"mg/L","statistic":"daily_max","direction":"max","kind":"limit","medium":"water_discharge","level":"national","route":"sewer","parameter_key":"cas:7440-22-4","place":["US"],"conditions":["route is sewer","cites is 40 CFR 415","the discharge is of the Subpart BA—Silver Nitrate Production Subcategory","existing sources (PSES)","table: Subpart BA—Silver Nitrate"],"cite":{"instrument":"us_40cfr415","title":"40 CFR Part 415 — PART 415—INORGANIC CHEMICALS MANUFACTURING POINT SOURCE CATEGORY","issuer":"U.S. Environmental Protection Agency","edition":"eCFR as of 2026-08-01","source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-01/title-40.xml?part=415","source_sha256":"ebf67428a51e85f12785b92d537e6878c5f9838c87722ac2db82b3db673d1e23","fetched_at":"2026-09-24","source_status":{"checked":"2026-10-15","status":"unchanged"},"section":"40 CFR 415.534 (PSES)","page":null,"quote":"Silver 1.0 0.5"}},{"id":"f7dbabe7424f9375","parameter":"Silver","value":"0.5","value_num":0.5,"unit":"mg/L","statistic":"monthly_avg","direction":"max","kind":"limit","medium":"water_discharge","level":"national","route":"sewer","parameter_key":"cas:7440-22-4","place":["US"],"conditions":["route is sewer","cites is 40 CFR 415","the discharge is of the Subpart BA—Silver Nitrate Production Subcategory","existing sources (PSES)","table: Subpart BA—Silver Nitrate"],"cite":{"instrument":"us_40cfr415","title":"40 CFR Part 415 — PART 415—INORGANIC CHEMICALS MANUFACTURING POINT SOURCE CATEGORY","issuer":"U.S. Environmental Protection Agency","edition":"eCFR as of 2026-08-01","source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-01/title-40.xml?part=415","source_sha256":"ebf67428a51e85f12785b92d537e6878c5f9838c87722ac2db82b3db673d1e23","fetched_at":"2026-09-24","source_status":{"checked":"2026-10-15","status":"unchanged"},"section":"40 CFR 415.534 (PSES)","page":null,"quote":"Silver 1.0 0.5"}},{"id":"aaba9139114719d8","parameter":"Silver","value":"0.533","value_num":0.533,"unit":"mg/troy ounce of gold and silver smelted","statistic":"daily_max","direction":"max","kind":"limit","medium":"water_discharge","level":"national","route":"direct","parameter_key":"cas:7440-22-4","place":["US"],"conditions":["route is direct","cites is 40 CFR 421","the discharge is of the Subpart W—Primary Precious Metals and Mercury Subcategory","existing sources (BPT)","(a) Smelter wet air pollution control.","table: BPT Limitations for the Primary Precious Metals and Mercury Subcategory"],"cite":{"instrument":"us_40cfr421","title":"40 CFR Part 421 — PART 421—NONFERROUS METALS MANUFACTURING POINT SOURCE CATEGORY","issuer":"U.S. Environmental Protection Agency","edition":"eCFR as of 2026-10-05","source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-10-05/title-40.xml?part=421","source_sha256":"d7cfd73b5bcf0e961e02ec53264492b2371277280003192841b7166b2a5012cf","fetched_at":"2026-10-09","source_status":{"checked":"2026-10-15","status":"unchanged"},"section":"40 CFR 421.252 (BPT)","page":null,"quote":"Silver 0.533 0.221"}},{"id":"5a52c94e4b7ab554","parameter":"Silver","value":"0.221","value_num":0.221,"unit":"mg/troy ounce of gold and silver smelted","statistic":"monthly_avg","direction":"max","kind":"limit","medium":"water_discharge","level":"national","route":"direct","parameter_key":"cas:7440-22-4","place":["US"],"conditions":["route is direct","cites is 40 CFR 421","the discharge is of the Subpart W—Primary Precious Metals and Mercury 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0.164 0.068"}},{"id":"01807f84ca347258","parameter":"Silver","value":"0.068","value_num":0.068,"unit":"mg/troy ounce of silver reduced in solution","statistic":"monthly_avg","direction":"max","kind":"limit","medium":"water_discharge","level":"national","route":"direct","parameter_key":"cas:7440-22-4","place":["US"],"conditions":["route is direct","cites is 40 CFR 421","the discharge is of the Subpart W—Primary Precious Metals and Mercury Subcategory","existing sources (BPT)","(b) Silver chloride reduction spent solution.","table: BPT Limitations for the Primary Precious Metals and Mercury Subcategory"],"cite":{"instrument":"us_40cfr421","title":"40 CFR Part 421 — PART 421—NONFERROUS METALS MANUFACTURING POINT SOURCE CATEGORY","issuer":"U.S. Environmental Protection Agency","edition":"eCFR as of 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CFR Part 421 — PART 421—NONFERROUS METALS MANUFACTURING POINT SOURCE CATEGORY","issuer":"U.S. Environmental Protection Agency","edition":"eCFR as of 2026-10-05","source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-10-05/title-40.xml?part=421","source_sha256":"d7cfd73b5bcf0e961e02ec53264492b2371277280003192841b7166b2a5012cf","fetched_at":"2026-10-09","source_status":{"checked":"2026-10-15","status":"unchanged"},"section":"40 CFR 421.252 (BPT)","page":null,"quote":"Silver 81.180 33.660"}},{"id":"942f2634ca3fd2c8","parameter":"Silver","value":"33.660","value_num":33.66,"unit":"mg/troy ounce of gold refined electrolytically","statistic":"monthly_avg","direction":"max","kind":"limit","medium":"water_discharge","level":"national","route":"direct","parameter_key":"cas:7440-22-4","place":["US"],"conditions":["route is direct","cites is 40 CFR 421","the discharge is of the Subpart W—Primary Precious Metals and Mercury Subcategory","existing sources (BPT)","(c) Electrolytic cells wet 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(BPT)","page":null,"quote":"Silver 0.021 0.009"}},{"id":"ceb0e3d42d609c42","parameter":"Silver","value":"76.340","value_num":76.34,"unit":"mg/kg (pounds per million pounds) of mercury condensed","statistic":"daily_max","direction":"max","kind":"limit","medium":"water_discharge","level":"national","route":"direct","parameter_key":"cas:7440-22-4","place":["US"],"conditions":["route is direct","cites is 40 CFR 421","the discharge is of the Subpart W—Primary Precious Metals and Mercury Subcategory","existing sources (BPT)","(e) Calciner wet air pollution control.","table: BPT Limitations for the Primary Precious Metals and Mercury Subcategory"],"cite":{"instrument":"us_40cfr421","title":"40 CFR Part 421 — PART 421—NONFERROUS METALS MANUFACTURING POINT SOURCE CATEGORY","issuer":"U.S. Environmental Protection Agency","edition":"eCFR as of 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CFR Part 421 — PART 421—NONFERROUS METALS MANUFACTURING POINT SOURCE CATEGORY","issuer":"U.S. Environmental Protection Agency","edition":"eCFR as of 2026-10-05","source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-10-05/title-40.xml?part=421","source_sha256":"d7cfd73b5bcf0e961e02ec53264492b2371277280003192841b7166b2a5012cf","fetched_at":"2026-10-09","source_status":{"checked":"2026-10-15","status":"unchanged"},"section":"40 CFR 421.252 (BPT)","page":null,"quote":"Silver 76.340 31.650"}},{"id":"204cb32b3b2d81b3","parameter":"Silver","value":"7.216","value_num":7.216,"unit":"mg/kg (pounds per million pounds) of mercury condensed","statistic":"daily_max","direction":"max","kind":"limit","medium":"water_discharge","level":"national","route":"direct","parameter_key":"cas:7440-22-4","place":["US"],"conditions":["route is direct","cites is 40 CFR 421","the discharge is of the Subpart W—Primary Precious Metals and Mercury Subcategory","existing sources (BPT)","(f) Calcine quench 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