Regulations last checked for updates: May 19, 2024

Title 40 - Protection of Environment last revised: May 16, 2024
§ 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]
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 421.124