Regulations last checked for updates: Oct 18, 2024

Title 40 - Protection of Environment last revised: Oct 16, 2024
§ 421.120 - Applicability: Description of the secondary silver subcategory.

The provisions of this subpart are applicable to discharges resulting from the production of silver from secondary silver facilities processing photographic and nonphotographic raw materials.

[49 FR 8821, Mar. 8, 1984; 49 FR 26739, June 29, 1984]
§ 421.121 - Specialized definitions.

For the purpose of this subpart the general definitions, abbreviations, and methods of analysis set forth in 40 CFR part 401 shall apply to this subpart.

§ 421.122 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the application of the best practicable control technology currently available.

Except as provided in 40 CFR 125.30 through 125.32, any existing point source subject to this subpart shall achieve the following effluent limitations representing the degree of effluent reduction attainable by the application of the best practicable technology currently available:

(a) Subpart L—Film Stripping.

BPT Effluent Limitations

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver from film stripping
Copper95.67050.350
Zinc73.51030.720
Ammonia (as N)6,712.0002,951.000
Total suspended solids2,065.000981.800
pH( 1)( 1)

1 Within the range of 7.5 to 10.0 at all times.

(b) Subpart L—Film Stripping Wet Air Pollution Control and Precipitation and Filtration of Film Stripping Solutions Wet Air Pollution Control.

BPT Effluent Limitations

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver from precipitation and filtration of film stripping solutions
Copper1.843.970
Zinc1.416.592
Ammonia (as N)129.30056.840
Total suspended solids39.77018.920
pH( 1)( 1)

1 Within the range of 7.5 to 10.0 at all times.

(c) Subpart L—Precipitation and Filtration of Film Stripping Solutions.

BPT Effluent Limitations

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver precipitated
Copper109.40057.570
Zinc84.05035.120
Ammonia (as N)7,674.0003,374.000
Total suspended solids2,361.0001,123.000
pH( 1)( 1)

1 Within the range of 7.5 to 10.0 at all times.

(d) Subpart L—Precipitation and Filtration of Photographic Solutions.

BPT Effluent Limitations

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver precipitated
Copper50.54026.600
Zinc38.83616.226
Ammonia (as N)3,545.0001,559.000
Total suspended solids1,090.600518.700
pH( 1)( 1)

1 Within the range of 7.5 to 10.0 at all times.

(e) Subpart L—Precipitation and Filtration of Photographic Solutions Wet Air Pollution Control.

BPT Effluent Limitations

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver from precipitation and filtration of photographic solutions
Copper23.07012.140
Zinc17.7307.406
Ammonia (as N)1,618.000711.400
Total suspended solids497.800236.800
pH( 1)( 1)

1 Within the range of 7.5 to 10.0 at all times.

(f) Subpart L—Electrolytic Refining.

BPT Effluent Limitations

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver from electrolytic refining
Copper1.444.760
Zinc1.110.464
Ammonia (as N)101.30044.540
Total suspended solids31.16014.820
pH( 1)( 1)

1 Within the range of 7.5 to 10.0 at all times.

(g) Subpart L—Furnace Wet Air Pollution Control.

BPT Effluent Limitations

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver roasted, smelted, or dried
Copper1.273.670
Zinc.978.409
Ammonia (as N)89.31039.260
Total suspended solids27.47013.070
pH( 1)( 1)

1 Within the range of 7.5 to 10.0 at all times.

(h) Subpart L—Leaching.

BPT Effluent Limitations

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver produced from leaching
Copper.164.086
Zinc.126.053
Ammonia (as N)11.4705.040
Total suspended solids3.5261.677
pH( 1)( 1)

1 Within the range of 7.5 to 10.0 at all times.

(i) Subpart L—Leaching Wet Air Pollution Control and Precipitation of Nonphotographic Solutions Wet Air Pollution Control.

BPT Effluent Limitations

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver produced from leaching or silver precipitated
Copper8.4174.430
Zinc6.4682.703
Ammonia (as N)590.500259.600
Total suspended solids181.70086.390
pH( 1)( 1)

1 Within the range of 7.5 to 10.0 at all times.

(j) Subpart L—Precipitation and Filtration of Nonphotographic Solutions.

BPT Effluent Limitations

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver precipitated
Copper5.8333.070
Zinc4.4821.873
Ammonia (as N)409.300179.900
Total suspended solids125.90059.870
pH( 1)( 1)

1 Within the range of 7.5 to 10.0 at all times.

(k) Subpart L—Floor and Equipment Washdown.

BPT Effluent Limitations

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver production
Copper.000.000
Zinc.000.000
Ammonia (as N).000.000
Total suspended solids.000.000
pH( 1)( 1)

1 Within the range of 7.5 to 10.0 at all times.

[49 FR 8821, Mar. 8, 1984, as amended at 49 FR 29795, July 24, 1984]
§ 421.123 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the application of the best available technology economically achievable.

Except as provided in 40 CFR 125.30 through 125.32, any existing point source subject to this subpart shall achieve the following effluent limitations representing the degree of effluent reduction attainable by the application of the best available technology economically achievable:

(a) Subpart L—Film Stripping.

BAT Effluent Limitations

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver from film stripping
Copper64.45030.720
Zinc51.36021.150
Ammonia (as N)6,712.0002,951.000

(b) Subpart L—Film Stripping Wet Air Pollution Control and Precipitation and Filtration of Film Stripping Solutions Wet Air Pollution Control.

BAT Effluent Limitations

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver from precipitation and filtration of film stripping solutions
Copper1.242.592
Zinc.990.408
Ammonia (as N)129.30056.840

(c) Subpart L—Precipitation and Filtration of Film Stripping Solutions.

BAT Effluent Limitations

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver precipitated
Copper73.69035.120
Zinc58.72024.180
Ammonia (as N)7,674.0003,374.000

(d) Subpart L—Precipitation and Filtration of Photographic Solutions.

BAT Effluent Limitations

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver precipitated
Copper34.04816.226
Zinc27.13211.172
Ammonia (as N)3,545.0001,559.000

(e) Subpart L—Precipitation and Filtration of Photographic Solutions Wet Air Pollution Control.

BAT Effluent Limitations

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver from precipitation and filtration of photographic solutions
Copper15.5407.406
Zinc12.3805.099
Ammonia (as N)1,618.000711.400

(f) Subpart L—Electrolytic Refining.

BAT Effluent Limitations

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver from electrolytic refining
Copper.973.464
Zinc.775.319
Ammonia (as N)101.30044.540

(g) Subpart L—Furnace Wet Air Pollution Control.

BAT Effluent Limitations

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver roasted, smelted, or dried
Copper.000.000
Zinc.000.000
Ammonia (as N).000.000

(h) Subpart L—Leaching.

BAT Effluent Limitations

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver produced from leaching
Copper.110.053
Zinc.088.036
Ammonia (as N)11.4705.040

(i) Subpart L—Leaching Wet Air Pollution Control and Precipitation of Nonphotographic Solutions Wet Air Pollution Control.

BAT Effluent Limitations

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver produced from leaching or silver precipitated
Copper5.6712.703
Zinc4.5191.861
Ammonia (as N)590.500259.600

(j) Subpart L—Precipitation and Filtration of Nonphotographic Solutions.

BAT Effluent Limitations

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver precipitated
Copper3.9301.873
Zinc3.1321.290
Ammonia (as N)409.300179.900

(k) Subpart L—Floor and Equipment Washdown.

BAT Effluent Limitations

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver production
Copper.000.000
Zinc.000.000
Ammonia (as N).000.000
§ 421.124 - Standards of performance for new sources.

Any new source subject to this subpart shall achieve the following new source performance standards:

(a) Subpart L—Film Stripping.

NSPS

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver from film stripping
Copper64.45030.720
Zinc51.36021.150
Ammonia (as N)6,712.0002,951.000
Total suspended solids755.300604.200
pH( 1)( 1)

1 Within the range of 7.5 to 10.0 at all times.

(b) Subpart L—Film Stripping Wet Air Pollution Control and Precipitation and Filtration of Film Stripping Solutions Wet Air Pollution Control.

NSPS

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver from precipitation and filtration of film stripping solutions
Copper1.242.592
Zinc.990.408
Ammonia (as N)129.30056.840
Total suspended solids14.55011.640
pH( 1)( 1)

1 Within the range of 7.5 to 10.0 at all times.

(c) Subpart L—Precipitation and Filtration of Film Stripping Solutions.

NSPS

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver precipitated
Copper73.69035.120
Zinc58.72024.180
Ammonia (as N)7,674.0003,374.000
Total suspended solids863.600690.900
pH( 1)( 1)

1 Within the range of 7.5 to 10.0 at all times.

(d) Subpart L—Precipitation and Filtration of Photographic Solutions.

NSPS

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver precipitated
Copper34.04816.226
Zinc27.13211.172
Ammonia (as N)3,545.0001,559.000
Total suspended solids399.000319.200
pH( 1)( 1)

1 Within the range of 7.5 to 10.0 at all times.

(e) Subpart L—Precipitation and Filtration of Photographic Solutions Wet Air Pollution Control.

NSPS

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver from precipitation and filtration of photographic solutions
Copper15.5407.406
Zinc12.3805.099
Ammonia (as N)1,618.000711.400
Total suspended solids182.100145.700
pH( 1)( 1)

1 Within the range of 7.5 to 10.0 at all times.

(f) Subpart L—Electrolytic Refining.

NSPS

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver from electrolytic refining
Copper.973.464
Zinc.775.319
Ammonia (as N)101.30044.540
Total suspended solids11.4009.120
pH( 1)( 1)

1 Within the range of 7.5 to 10.0 at all times.

(g) Subpart L—Furnace Wet Air Pollution Control.

NSPS

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver roasted, smelted, or dried
Copper.000.000
Zinc.000.000
Ammonia (as N).000.000
Total suspended solids.000.000
pH( 1)( 1)

1 Within the range of 7.5 to 10.0 at all times.

(h) Subpart L—Leaching.

NSPS

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver produced from leaching
Copper.110.053
Zinc.088.036
Ammonia (as N)11.4705.040
Total suspended solids1.2901.032
pH( 1)( 1)

1 Within the range of 7.5 to 10.0 at all times.

(i) Subpart L—Leaching Wet Air Pollution Control and Precipitation of Nonphotographic Solutions Wet Air Pollution Control.

NSPS

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver produced from leaching or silver precipitated
Copper5.6712.703
Zinc4.5191.861
Ammonia (as N)590.500259.600
Total suspended solids66.45053.160
pH( 1)( 1)

1 Within the range of 7.5 to 10.0 at all times.

(j) Subpart L—Precipitation and Filtration of Nonphotograhic Solutions.

NSPS

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver precipitated
Copper3.9301.873
Zinc3.1321.290
Ammonia (as N)409.300179.900
Total suspended solids46.05036.840
pH( 1)( 1)

1 Within the range of 7.5 to 10.0 at all times.

(k) Subpart L—Floor and Equipment Washdown.

NSPS

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver production
Copper.000.000
Zinc.000.000
Ammonia (as N).000.000
Total suspended solids.000.000
pH( 1)( 1)

1 Within the range of 7.5 to 10.0 at all times.

[49 FR 8821, Mar. 8, 1984, as amended at 49 FR 29795, July 24, 1984]
§ 421.125 - Pretreatment standards for existing sources.

Except as provided in 40 CFR 403.7 and 403.13, any existing 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 existing sources. The mass of wastewater pollutants in secondary silver process wastewater introduced into a POTW must not exceed the following values.

(a) Subpart L—Film Stripping.

PSES

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver from film stripping
Copper64.45030.720
Zinc51.36021.150
Ammonia (as N)6,712.0002,951.000

(b) Subpart L—Film Stripping Wet Air Pollution Control and Precipitation and Filtration of Film Stripping Solutions Wet Air Pollution Control.

PSES

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver from precipitation and filtration of film stripping solutions
Copper1.242.592
Zinc.990.408
Ammonia (as N)129.30056.840

(c) Subpart L—Precipitation and Filtration of Film Stripping Solutions.

PSES

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver precipitated
Copper73.69035.120
Zinc58.72024.180
Ammonia (as N)7,674.0003,374.000

(d) Subpart L—Precipitation and Filtration of Photographic Solutions.

PSES

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver precipitated
Copper34.04816.226
Zinc27.13211.172
Ammonia (as N)3,545.0001,559.000

(e) Subpart L—Precipitation and Filtration of Photographic Solutions Wet Air Pollution Control.

PSES

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver from precipitation and filtration of photographic solutions
Copper15.5407.406
Zinc12.3805.099
Ammonia (as N)1,618.000711.400

(f) Subpart L—Electrolytic Refining.

PSES

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver from electrolytic refining
Copper.973.464
Zinc.775.319
Ammonia (as N)101.30044.540

(g) Subpart L—Furnace Wet Air Pollution Control.

PSES

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver roasted, smelted, or dried
Copper.000.000
Zinc.000.000
Ammonia (as N).000.000

(h) Subpart L—Leaching.

PSES

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver produced from leaching
Copper.110.053
Zinc.088.036
Ammonia (as N)11.4705.040

(i) Subpart L—Leaching Wet Air Pollution Control and Precipitation of Nonphotographic Solutions Wet Air Pollution Control.

PSES

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver produced from leaching or silver precipitated
Copper5.6712.703
Zinc4.5191.861
Ammonia (as N)590.500259.600

(j) Subpart L—Precipitation and Filtration of Nonphotographic Solutions.

PSES

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver precipitated
Copper3.9301.873
Zinc3.1321.290
Ammonia (as N)409.300179.900

(k) Subpart L—Floor and Equipment Washdown.

PSES

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver production
Copper.000.000
Zinc.000.000
Ammonia (as N).000.000
§ 421.126 - Pretreatment standards for new sources.

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:

(a) Subpart L—Film Stripping.

PSNS

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver from film stripping
Copper64.45030.720
Zinc51.36021.150
Ammonia (as N)6,712.0002,951.000

(b) Subpart L—Film Stripping Wet Air Pollution Control and Precipitation and Filtration of Film Stripping Solutions Wet Air Pollution Control.

PSNS

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver from precipitation and filtration of film stripping solutions
Copper1.242.592
Zinc.990.408
Ammonia (as N)129.30056.840

(c) Subpart L—Precipitation and Filtration of Film Stripping Solutions.

PSNS

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver precipitated
Copper73.69035.120
Zinc58.72024.180
Ammonia (as N)7,674.0003,374.000

(d) Subpart L—Precipitation and Filtration of Photographic Solutions.

PSNS

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver precipitated
Copper34.04816.226
Zinc27.13211.172
Ammonia (as N)3,545.0001,559.000

(e) Subpart L—Precipitation and Filtration of Photographic Solutions Wet Air Pollution Control.

PSNS

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver from precipitation and filtration of photographic solutions
Copper15.5407.406
Zinc12.3805.099
Ammonia (as N)1,618.000711.400

(f) Subpart L—Electrolytic Refining.

PSNS

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver from electrolytic refining
Copper.973.464
Zinc.775.319
Ammonia (as N)101.30044.540

(g) Subpart L—Furnace Wet Air Pollution Control.

PSNS

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver roasted, smelted or dried
Copper.000.000
Zinc.000.000
Ammonia (as N).000.000

(h) Subpart L—Leaching.

PSNS

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver produced from leaching
Copper.110.053
Zinc.088.036
Ammonia (as N)11.4705.040

(i) Subpart L—Leaching Wet Air Pollution Control and Precipitation of Nonphotographic Solutions Wet Air Pollution Control.

PSNS

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver produced from leaching or silver precipitated
Copper5.6712.703
Zinc4.5191.861
Ammonia (as N)590.500259.600

(j) Subpart L—Precipitation and Filtration of Nonphotographic Solutions.

PSNS

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver precipitated
Copper3.9301.873
Zinc3.1321.290
Ammonia (as N)409.300179.900

(k) Subpart L—Floor and Equipment Washdown.

PSNS

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver production
Copper.000.000
Zinc.000.000
Ammonia (as N).000.000
[49 FR 8821, Mar. 8, 1984; 49 FR 26739, June 29, 1984]
§ 421.127 - [Reserved]
authority: Secs. 301, 304 (b), (c), (e), and (g), 306 (b) and (c), 307 (b) and (c), 308 and 501 of the Clean Water Act (the Federal Water Pollution Control Act Amendments of 1972, as amended by the Clean Water Act of 1977) and the Water Quality Act of 1987 (the “Act”); 33 U.S.C. 1311,1314,c,e,and, 1316 (b) andc, 1317 (b) andc,1318; 86 Stat. 816, Pub. L. 92-500; 91 Stat. 1567, Pub. L. 95-217; 101 Stat. 7, Pub. L. 100-4
source: 49 FR 8790, Mar. 8, 1984, unless otherwise noted.
cite as: 40 CFR 421.122