40 CFR 421.324 - Standards of performance for new sources.

Regulations last checked for updates: Feb 11, 2026

Title 40 - Protection of Environment last revised: Dec 22, 2026

View all text of Subpart AD [§ 421.320 - § 421.327]

§ 421.324 - Standards of performance for new sources.

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

(a) Refinery sump filtrate.

NSPS for the Secondary Uranium Subcategory

Pollutant or pollutant property	Maximum for any 1 day	Maximum for monthly average
	mg/kg (pounds per million pounds) of uranium processed in the refinery
Chromium (total)	27.14	11.00
Copper	93.88	44.74
Nickel	40.34	27.14
Fluoride	2,567.00	1,459.00
Total suspended solids	1,100.00	880.10
pH	( ¹)	( ¹)

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

(b) Slag leach reslurry.

NSPS for the Secondary Uranium Subcategory

Pollutant or pollutant property	Maximum for any 1 day	Maximum for monthly average
	mg/kg (pounds per million pounds) of uranium processed in the refinery
Chromium (total)	1.689	0.685
Copper	5.844	2.785
Nickel	2.511	1.689
Fluoride	159.800	90.860
Total suspended solids	68.490	54.790
pH	( ¹)	( ¹)

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

(c) Solvent extraction raffinate filtrate.

NSPS for the Secondary Uranium Subcategory

Pollutant or pollutant property	Maximum for any 1 day	Maximum for monthly average
	mg/kg (pounds per million pounds) of uranium processed in the refinery
Chromium (total)	2.357	0.955
Copper	8.152	3.885
Nickel	3.503	2.357
Fluoride	222.900	126.700
Total suspended solids	95.540	76.430
pH	( ¹)	( ¹)

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

(d) Digestion wet air pollution control.

NSPS for the Secondary Uranium Subcategory

Pollutant or pollutant property	Maximum for any 1 day	Maximum for monthly average
	mg/kg (pounds per million pounds) of uranium processed in the refinery
Chromium (total)	0.000	0.000
Copper	0.000	0.000
Nickel	0.000	0.000
Fluoride	0.000	0.000
Total suspended solids	0.000	0.000
pH	( ¹)	( ¹)

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

(e) Evaporation and denitration wet air pollution control

NSPS for the Secondary Uranium Subcategory

Pollutant or pollutant property	Maximum for any 1 day	Maximum for monthly average
	mg/kg (pounds per million pounds) of uranium trioxide produced
Chromium (total)	0.000	0.000
Copper	0.000	0.000
Nickel	0.000	0.000
Fluoride	0.000	0.000
Total suspended solids	0.000	0.000
pH	( ¹)	( ¹)

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

(f) Hydrofluorination alkaline scrubber.

NSPS for the Secondary Uranium Subcategory

Pollutant or pollutant property	Maximum for any 1 day	Maximum for monthly average
	mg/kg (pounds per million pounds) of uranium tetrafluoride produced
Chromium (total)	0.007	0.003
Copper	0.026	0.012
Nickel	0.011	0.007
Fluoride	0.700	0.398
Total suspended solids	0.300	0.240
pH	( ¹)	( ¹)

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

(g) Hydrofluorination water scrubber.

NSPS for the Secondary Uranium Subcategory

Pollutant or pollutant property	Maximum for any 1 day	Maximum for monthly average
	mg/kg (pounds per million pounds) of uranium tetrafluoride produced
Chromium (total)	0.000	0.000
Copper	0.000	0.000
Nickel	0.000	0.000
Fluoride	0.000	0.000
Total suspended solids	0.000	0.000
pH	( ¹)	( ¹)

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

(h) Magnesium reduction and casting floor wash.

NSPS for the Secondary Uranium Subcategory

Pollutant or pollutant property	Maximum for any 1 day	Maximum for monthly average
	mg/kg (pounds per million pounds) of uranium produced by magnesium reduction
Chromium (total)	0.011	0.005
Copper	0.039	0.018
Nickel	0.017	0.011
Fluoride	1.054	0.599
Total suspended solids	0.452	0.361
pH	( ¹)	( ¹)

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

(i) Laundry wastewater.

NSPS for the Secondary Uranium Subcategory

Pollutant or pollutant property	Maximum for any 1 day	Maximum for monthly average
	mg/kg (pounds per million pounds) of uranium produced by magnesium reduction
Chromium (total)	0.036	0.014
Copper	0.123	0.059
Nickel	0.053	0.036
Fluoride	3.360	1.910
Total suspended solids	1.440	1.152
pH	( ¹)	( ¹)

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

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 421.324

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