Regulations last checked for updates: May 01, 2025
Title 40 - Protection of Environment last revised: Nov 01, 2025
§ 421.70 - Applicability: Description of the primary lead subcategory.
The provisions of this subpart are applicable to discharges resulting from the production of lead at primary lead smelters and refineries.
§ 421.71 - 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.
§ 421.72 - 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 control technology currently available:
(a) Subpart G—Sinter Plant Materials Handling Wet Air Pollution Control.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of sinter production
|
| Lead | 594.000 | 270.000
|
| Zinc | 525.000 | 219.600
|
| Total suspended solids | 14,760.000 | 7,020.000
|
| pH | (
1) | (
1)
|
(b) Subpart G—Blast Furnace Wet Air Pollution Control.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of blast furance lead bullion produced
|
| Lead | .000 | .000
|
| Zinc | .000 | .000
|
| Total suspended solids | .000 | .000
|
| pH | (
1) | (
1)
|
(c) Subpart G—Blast Furnace Slag Granulation.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of blast furance lead bullion produced
|
| Lead | 6,155.000 | 2,798.000
|
| Zinc | 5,446.000 | 2,276.000
|
| Total suspended solids | 153,000.000 | 72,740.000
|
| pH | (
1) | (
1)
|
(d) Subpart G—Dross Reverberatory Slag Granulation.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of slag, speiss, or matte granulated
|
| Lead | 9,499.000 | 4,318.000
|
| Zinc | 8,405.000 | 3,512.000
|
| Total suspended solids | 236,000.000 | 112,300.000
|
| pH | (
1) | (
1)
|
(e) Subpart G—Dross Reverberatory Furnace Wet Air Pollution Control.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of dross reverberatory furnace production
|
| Lead | 15,920.000 | 7,235.000
|
| Zinc | 14,080.000 | 5,884.000
|
| Total suspended solids | 395,500.000 | 188,100.000
|
| pH | (
1) | (
1)
|
(f) Subpart G—Zinc Fuming Wet Air Pollution Control.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of blast furance lead bullion produced
|
| Lead | 702.900 | 319.500
|
| Zinc | 622.000 | 259.900
|
| Total suspended solids | 17,470.000 | 8,307.000
|
| pH | (
1) | (
1)
|
(g) Subpart G—Hard Lead Refining Slag Granulation.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of hard lead produced
|
| Lead | .000 | .000
|
| Zinc | .000 | .000
|
| Total suspended solids | .000 | .000
|
| pH | (
1) | (
1)
|
(h) Subpart G—Hard Lead Refining Air Pollution Control.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of hard lead produced
|
| Lead | 32,730.000 | 14,880.000
|
| Zinc | 28,960.000 | 12,100.000
|
| Total suspended solids | 813,300.000 | 386,800.000
|
| pH | (
1) | (
1)
|
(i) Subpart G—Facility Washdown.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of lead bullion produced
|
| Lead | .000 | .000
|
| Zinc | .000 | .000
|
| Total suspended solids | .000 | .000
|
| pH | (
1) | (
1)
|
(j) Subpart G—Employee Handwash.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of lead bullion produced
|
| Lead | 5.445 | 2.475
|
| Zinc | 4.818 | 2.013
|
| Total suspended solids | 135.300 | 64.350
|
| pH | (
1) | (
1)
|
(k) Subpart G—Respirator Wash.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of lead bullion produced
|
| Lead | 8.745 | 3.975
|
| Zinc | 7.738 | 3.233
|
| Total suspended solids | 217.300 | 103.400
|
| pH | (
1) | (
1)
|
(l) Subpart G—Laundering of Uniforms.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of lead bullion produced
|
| Lead | 25.580 | 11.630
|
| Zinc | 22.630 | 9.455
|
| Total suspended solids | 635.500 | 302.300
|
| pH | (
1) | (
1)
|
§ 421.73 - 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 G—Sinter Plant Materials Handling Wet Air Pollution Control.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of sinter production
|
| Lead | 100.800 | 46.800
|
| Zinc | 367.200 | 151.200 |
(b) Subpart G—Blast Furnace Wet Air Pollution Control.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of blast furnace lead bullion produced
|
| Lead | .000 | .000
|
| Zinc | .000 | .000 |
(c) Subpart G—Blast Furnace Slag Granulation.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of blast furnace lead bullion produced
|
| Lead | .000 | .000
|
| Zinc | .000 | .000 |
(d) Subpart G—Dross Reverberatory Slag Granulation.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of slag, speiss, or matte granulated
|
| Lead | 1,612.000 | 748.400
|
| Zinc | 5,872.000 | 2,418.000 |
(e) Subpart G—Dross Reverberatory Furnace Wet Air Pollution Control.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of dross reverberatory furnace production
|
| Lead | .000 | .000
|
| Zinc | .000 | .000 |
(f) Subpart G—Zinc Fuming Wet Air Pollution Control.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of blast furnance lead bullion produced
|
| Lead | .000 | .000
|
| Zinc | .000 | .000 |
(g) Subpart G—Hard Lead Refining Slag Granulation.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of hard lead produced
|
| Lead | .000 | .000
|
| Zinc | .000 | .000 |
(h) Subpart G—Hard Lead Refining Wet Air Pollution Control.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of hard lead produced
|
| Lead | .000 | .000
|
| Zinc | .000 | .000 |
(i) Subpart G—Facility Washdown.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of lead bullion produced
|
| Lead | .000 | .000
|
| Zinc | .000 | .000 |
(j) Subpart G—Employee Handwash.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of lead bullion produced
|
| Lead | .924 | .429
|
| Zinc | 3.366 | 1.386 |
(k) Subpart G—Respirator Wash.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of lead bullion produced
|
| Lead | 1.484 | .689
|
| Zinc | 5.406 | 2.226 |
(l) Subpart G—Laundering of Uniforms.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of lead bullion produce
|
| Lead | 4.340 | 2.015
|
| Zinc | 15.810 | 6.510 |
§ 421.74 - Standards of performance for new sources.
Any new source subject to this subpart must achieve the following performance standards:
(a) Subpart G—Sinter Plant Materials Handling Wet Air Pollution Control.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of sinter production
|
| Lead | .000 | .000
|
| Zinc | .000 | .000
|
| Total suspended solids | .000 | .000
|
| pH | (
1) | (
1)
|
(b) Subpart G—Blast Furnace Wet Air Pollution Control.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of blast furnace lead bullion produced
|
| Lead | .000 | .000
|
| Zinc | .000 | .000
|
| Total suspended solids | .000 | .000
|
| pH | (
1) | (
1)
|
(c) Subpart G—Blast Furnace Slag Granulation.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of blast furnance lead bullion produced
|
| Lead | .000 | .000
|
| Zinc | .000 | .000
|
| Total suspended solids | .000 | .000
|
| pH | (
1) | (
1)
|
(d) Subpart G—Dross Reverberatory Slag Granulation.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of slag, speiss, or matte granulated
|
| Lead | .000 | .000
|
| Zinc | .000 | .000
|
| Total suspended solids | .000 | .000
|
| pH | (
1) | (
1)
|
(e) Subpart G—Dross Reverberatory Furnace Wet Air Pollution Control.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of dross reverberatory furnace production
|
| Lead | .000 | .000
|
| Zinc | .000 | .000
|
| Total suspended solids | .000 | .000
|
| pH | (
1) | (
1)
|
(f) Subpart G—Zinc Fuming Wet Air Pollution Control.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of blast furnace lead bullion produced
|
| Lead | .000 | .000
|
| Zinc | .000 | .000
|
| Total suspended solids | .000 | .000
|
| pH | (
1) | (
1)
|
(g) Subpart G—Hard Lead Refining Slag Granulation.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of hard lead produced
|
| Lead | .000 | .000
|
| Zinc | .000 | .000
|
| Total suspended solids | .000 | .000
|
| pH | (
1) | (
1)
|
(h) Subpart G—Hard Lead Refining Wet Air Pollution Control.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of hard lead produced
|
| Lead | .000 | .000
|
| Zinc | .000 | .000
|
| Total suspended solids | .000 | .000
|
| pH | (
1) | (
1)
|
(i) Subpart G—Facility Washdown.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of lead bullion produced
|
| Lead | .000 | .000
|
| Zinc | .000 | .000
|
| Total suspended solids | .000 | .000
|
| pH | (
1) | (
1)
|
(j) Subpart G—Employee Handwash.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of lead bullion produced
|
| Lead | .924 | .429
|
| Zinc | 3.366 | 1.386
|
| Total suspended solids | 49.500 | 39.600
|
| pH | (
1) | (
1)
|
(k) Subpart G—Respirator Wash.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of lead bullion produced
|
| Lead | 1.484 | .689
|
| Zinc | 5.406 | 2.226
|
| Total suspended solids | 79.500 | 63.600
|
| pH | (
1) | (
1)
|
(l) Subpart G—Laundering of Uniforms.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of lead bullion produced
|
| Lead | 4.340 | 2.015
|
| Zinc | 15.810 | 6.510
|
| Total suspended solids | 232.500 | 186.000
|
| pH | (
1) | (
1)
|
§ 421.75 - 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 mut comply with 40 CFR part 403 and achieve the following pretreatment standards for existing sources. The mass of wastewater pollutants in primary lead process wastewater introduced into a POTW shall not exceed the following values:
(a) Subpart G—Sinter Plant Materials Handling Wet Air Pollution Control.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of sinter production
|
| Lead | 100.800 | 46.800
|
| Zinc | 367.200 | 151.200 |
(b) Subpart G—Blast Furnace Wet Air Pollution Control.
| Pollutant or polluntant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pound per billion pounds) of blast furnance lead bullion produced
|
| Lead | .000 | .000
|
| Zinc | .000 | .000 |
(c) Subpart G—Blast Furnace Slag Granulation.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pound per billion pounds) of blast furance lead bullion produced
|
| Lead | .000 | .000
|
| Zinc | .000 | .000 |
(d) Subpart G—Dross Reverberatory Slag Granulation.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of slag, speiss, or matte granulated
|
| Lead | 1,612.000 | 748.400
|
| Zinc | 5,872.000 | 2,418.000 |
(e) Subpart G—Dross Reverberatory Furnance Wet Air Pollution Control.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of dross reverberatory furnace production
|
| Lead | .000 | .000
|
| Zinc | .000 | .000 |
(f) Subpart G—Zinc Fuming Wet Air Pollution Control.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of blast furnace lead bullion produced
|
| Lead | .000 | .000
|
| Zinc | .000 | .000 |
(g) Subpart G—Hard Lead Refining Slag Granulation.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of hard lead produced
|
| Lead | .000 | .000
|
| Zinc | .000 | .000 |
(h) Subpart G—Hard Lead Refining Wet Air Pollution Control.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of hard lead produced
|
| Lead | .000 | .000
|
| Zinc | .000 | .000 |
(i) Subpart G—Facility Washdown.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of lead bullion produced.
|
| Lead | .000 | .000
|
| Zinc | .000 | .000 |
(j) Subpart G—Employee Handwash.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of lead bullion produced
|
| Lead | .924 | .429
|
| Zinc | 3.366 | 1.386 |
(k) Subpart G—Respirator Wash.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of lead bullion produced
|
| Lead | 1.484 | .689
|
| Zinc | 5.406 | 2.226 |
(l) Subpart G—Laundering of Uniforms.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of lead bullion produced
|
| Lead | 4.340 | 2.015
|
| Zinc | 15.810 | 6.510 |
§ 421.76 - 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 primary lead process wastewaters introduced into a POTW shall not exceed the following values.
(a) Subpart G—Sinter Plant Materials Handling Wet Air Pollution Control.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of sinter production
|
| Lead | .000 | .000
|
| Zinc | .000 | .000 |
(b) Subpart G—Blast Furnace Wet Air Pollution Control.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of blast furnace lead bullion produced
|
| Lead | .000 | .000
|
| Zinc | .000 | .000 |
(c) Subpart G—Blast Furnace Slag Granulation.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of blast furnace lead bullion produced
|
| Lead | .000 | .000
|
| Zinc | .000 | .000 |
(d) Subpart G—Dross Reverberatory Slag Granulation.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of slag, speiss, or matte granulated
|
| Lead | .000 | .000
|
| Zinc | .000 | .000 |
(e) Subpart G—Dross Reverberatory Furnace Wet Air Pollution Control.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of dross reverberatory furnace production
|
| Lead | .000 | .000
|
| Zinc | .000 | .000 |
(f) Subpart G—Zinc Fuming Wet Air Pollution Control.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of blast furnace lead bullion produced
|
| Lead | .000 | .000
|
| Zinc | .000 | .000 |
(g) Subpart G—Hard Lead Refining Slag Granulation.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of hard lead produced
|
| Lead | .000 | .000
|
| Zinc | .000 | .000 |
(h) Subpart G—Hard Lead Refining Wet Air Pollution Control.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of hard lead produced
|
| Lead | .000 | .000
|
| Zinc | .000 | .000 |
(i) Subpart G—Facility Washdown.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of lead bullion produced
|
| Lead | .000 | .000
|
| Zinc | .000 | .000 |
(j) Subpart G—Employee Handwash.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of lead bullion produced
|
| Lead | .924 | .429
|
| Zinc | 3.366 | 1.386 |
(k) Subpart G—Respirator Wash.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of lead bullion produced
|
| Lead | 1.484 | .689
|
| Zinc | 5.406 | 2.226 |
(l) Subpart G—Laundering of Uniforms.
| Pollutant or pollutant property
| Maximum for any 1 day
| Maximum for monthly average
|
|---|
| mg/kkg (pounds per billion pounds) of lead bullion produced
|
| Lead | 4.340 | 2.015
|
| Zinc | 15.810 | 6.510 |
§ 421.77 - [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) and
c, 1317 (b) and
c,
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 421.74