40 CFR § 421.334 - Standards of performance for new sources.
---
identifier: "/us/cfr/t40/s421.334"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "40 CFR § 421.334 - Standards of performance for new sources."
title_number: 40
title_name: "Protection of Environment"
section_number: "421.334"
section_name: "Standards of performance for new sources."
chapter_name: "ENVIRONMENTAL PROTECTION AGENCY"
subchapter_number: "N"
subchapter_name: "EFFLUENT GUIDELINES AND STANDARDS"
part_number: "421"
part_name: "NONFERROUS METALS MANUFACTURING POINT SOURCE CATEGORY"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
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 (b), (c), (e), and (g), 1316 (b) and (c), 1317 (b) and (c), 1318 and 1361; 86 Stat. 816, Pub. L. 92-500; 91 Stat. 1567, Pub. L. 95-217; 101 Stat. 7, Pub. L. 100-4."
regulatory_source: "49 FR 8790, Mar. 8, 1984, unless otherwise noted."
cfr_part: "421"
---
# 421.334 Standards of performance for new sources.
Any new source subject to this subpart shall achieve the following new source performance standards:
(a) Sand drying wet air pollution control.
NSPS for the Primary Zirconium and Hafnium Subcategory
| Pollutant or pollutant property | Maximum for any 1 day | Maximum for monthly average |
| --- | --- | --- |
| | mg/kg (pounds per million pounds) of zirconium dioxide and hafnium dioxide produced | |
| Chromium (total) | 0.210 | 0.085 |
| Cyanide (total) | 0.114 | 0.045 |
| Lead | 0.159 | 0.074 |
| Nickel | 0.312 | 0.210 |
| Ammonia (as N) | 75.710 | 33.280 |
| Total suspended solids | 8.520 | 6.816 |
| pH | () | () |
| Within the range of 7.5 to 10.0 at all times. | | |
(b) Sand chlorination off-gas wet air pollution control.
NSPS for the Primary Zirconium and Hafnium Subcategory
| Pollutant or pollutant property | Maximum for any 1 day | Maximum for monthly average |
| --- | --- | --- |
| | mg/kg (pounds per million pounds) of zirconium dioxide and hafnium dioxide produced | |
| Chromium (total) | 16.080 | 6.521 |
| Cyanide (total) | 8.694 | 3.478 |
| Lead | 12.170 | 5.651 |
| Nickel | 23.910 | 16.080 |
| Ammonia (as N) | 5,795.000 | 2,547.000 |
| Total suspended solids | 652.100 | 521.000 |
| pH | () | () |
| Within the range of 7.5 to 10.0 at all times. | | |
(c) Sand chlorination area-vent wet air pollution control.
NSPS for the Primary Zirconium and Hafnium Subcategory
| Pollutant or pollutant property | Maximum for any 1 day | Maximum for monthly average |
| --- | --- | --- |
| | mg/kg (pounds per million pounds) of zirconium dioxide and hafnium dioxide produced | |
| Chromium (total) | 3.154 | 1.279 |
| Cyanide (total) | 1.705 | 0.682 |
| Lead | 2.387 | 1.108 |
| Nickel | 4.688 | 3.154 |
| Ammonia (as N) | 1,136.000 | 499.500 |
| Total suspended solids | 127.900 | 102.300 |
| pH | () | () |
| Within the range of 7.5 to 10.0 at all times. | | |
(d) SiC<sub>14</sub> purification wet air pollution control.
NSPS for the Primary Zirconium and Hafnium Subcategory
| Pollutant or pollutant property | Maximum for any 1 day | Maximum for monthly average |
| --- | --- | --- |
| | mg/kg (pounds per million pounds) of zirconium dioxide and hafnium dioxide produced | |
| Chromium (total) | 2.774 | 1.125 |
| Cyanide (total) | 1.500 | 0.600 |
| Lead | 2.099 | 0.975 |
| Nickel | 4.124 | 2.774 |
| Ammonia (as N) | 999.500 | 439.400 |
| Total suspended solids | 112.500 | 89.980 |
| pH | () | () |
| Within the range of 7.5 to 10.0 at all times. | | |
(e) Feed makeup wet air pollution control.
NSPS for the Primary Zirconium and Hafnium Subcategory
| Pollutant or pollutant property | Maximum for any 1 day | Maximum for monthly average |
| --- | --- | --- |
| | mg/kg (pounds per million pounds) of zirconium dioxide and hafnium dioxide produced | |
| Chromium (total) | 2.103 | 0.852 |
| Cyanide (total) | 1.137 | 0.455 |
| Lead | 1.591 | 0.739 |
| Nickel | 3.126 | 2.103 |
| Ammonia (as N) | 757.500 | 333.000 |
| Total suspended solids | 85.250 | 68.200 |
| pH | () | () |
| Within the range of 7.5 to 10.0 at all times. | | |
(f) Iron extraction (MIBK) steam stripper bottoms.
NSPS for the Primary Zirconium and Hafnium Subcategory
| Pollutant or pollutant property | Maximum for any 1 day | Maximum for monthly average |
| --- | --- | --- |
| | mg/kg (pounds per million pounds) of zirconium dioxide and hafnium dioxide produced | |
| Chromium (total) | 0.830 | 0.337 |
| Cyanide (total) | 0.449 | 0.180 |
| Lead | 0.628 | 0.292 |
| Nickel | 1.234 | 0.830 |
| Ammonia (as N) | 299.100 | 131.500 |
| Total suspended solids | 33.660 | 26.930 |
| pH | () | () |
| Within the range of 7.5 to 10.0 at all times. | | |
(g) Zirconium filtrate.
NSPS for the Primary Zirconium and Hafnium Subcategory
| Pollutant or pollutant property | Maximum for any 1 day | Maximum for monthly average |
| --- | --- | --- |
| | mg/kg (pounds per million pounds) of zirconium dioxide and hafnium dioxide produced | |
| Chromium (total) | 14.350 | 5.819 |
| Cyanide (total) | 7.758 | 3.103 |
| Lead | 10.860 | 5.043 |
| Nickel | 21.330 | 14.350 |
| Ammonia (as N) | 5,171.000 | 2,273.000 |
| Total suspended solids | 581.900 | 465.500 |
| pH | () | () |
| Within the range of 7.5 to 10.0 at all times. | | |
(h) Hafnium filtrate.
NSPS for the Primary Zirconium and Hafnium Subcategory
| Pollutant or pollutant property | Maximum for any 1 day | Maximum for monthly average |
| --- | --- | --- |
| | mg/kg (pounds per million pounds) of zirconium dioxide and hafnium dioxide produced | |
| Chromium (total) | 0.000 | 0.000 |
| Cyanide (total) | 0.000 | 0.000 |
| Lead | 0.000 | 0.000 |
| Nickel | 0.000 | 0.000 |
| Ammonia (as N) | 0.000 | 0.000 |
| Total suspended solids | 0.000 | 0.000 |
| pH | () | () |
| Within the range of 7.5 to 10.0 at all times. | | |
(i) Calcining caustic wet air pollution control.
NSPS for the Primary Zirconium and Hafnium Subcategory
| Pollutant or pollutant property | Maximum for any 1 day | Maximum for monthly average |
| --- | --- | --- |
| | mg/kg (pounds per million pounds) of zirconium dioxide and hafnium dioxide produced | |
| Chromium (total) | 3.329 | 1.350 |
| Cyanide (total) | 1.799 | 0.720 |
| Lead | 2.519 | 1.170 |
| Nickel | 4.948 | 3.329 |
| Ammonia (as N) | 1,199.000 | 527.200 |
| Total suspended solids | 135.000 | 108.000 |
| pH | () | () |
| Within the range of 7.5 to 10.0 at all times. | | |
(j) Pure chlorination wet air pollution control.
NSPS for the Primary Zirconium and Hafnium Subcategory
| Pollutant or pollutant property | Maximum for any 1 day | Maximum for monthly average |
| --- | --- | --- |
| | mg/kg (pounds per million pounds) of zirconium and hafnium produced | |
| Chromium (total) | 14.180 | 5.748 |
| Cyanide (total) | 7.663 | 3.065 |
| Lead | 10.730 | 4.981 |
| Nickel | 21.070 | 14.180 |
| Ammonia (as N) | 5,108.000 | 2,245.000 |
| Total suspended solids | 574.800 | 459.800 |
| pH | () | () |
| Within the range of 7.5 to 10.0 at all times. | | |
(k) Reduction area-vent wet air pollution control.
NSPS for the Primary Zirconium and Hafnium Subcategory
| Pollutant or pollutant property | Maximum for any 1 day | Maximum for monthly average |
| --- | --- | --- |
| | mg/kg (pounds per million pounds) of zirconium and hafnium produced | |
| Chromium (total) | 1.364 | 0.553 |
| Cyanide (total) | 0.737 | 0.295 |
| Lead | 1.032 | 0.479 |
| Nickel | 2.027 | 1.364 |
| Ammonia (as N) | 491.300 | 216.000 |
| Total suspended solids | 55.290 | 44.230 |
| pH | () | () |
| Within the range of 7.5 to 10.0 at all times. | | |
(l) Magnesium recovery off-gas wet air pollution control.
NSPS for the Primary Zirconium and Hafnium Subcategory
| Pollutant or pollutant property | Maximum for any 1 day | Maximum for monthly average |
| --- | --- | --- |
| | mg/kg (pounds per million pounds) of zirconium and hafnium produced | |
| Chromium (total) | 7.671 | 3.110 |
| Cyanide (total) | 4.147 | 1.659 |
| Lead | 5.805 | 2.695 |
| Nickel | 11.400 | 7.671 |
| Ammonia (as N) | 2,764.000 | 1,215.000 |
| Total suspended solids | 404.300 | 248.800 |
| pH | () | () |
| Within the range of 7.5 to 10.0 at all times. | | |
(m) Magnesium recovery area-vent wet air pollution control.
NSPS Limitations for the Primary Zirconium and Hafnium Subcategory
| Pollutant or pollutant property | Maximum for any 1 day | Maximum for monthly average |
| --- | --- | --- |
| | mg/kg (pounds per million pounds) of zirconium and hafnium produced | |
| Chromium (total) | 4.262 | 1.728 |
| Cyanide (total) | 2.304 | 0.921 |
| Lead | 3.225 | 1.497 |
| Nickel | 6.335 | 4.262 |
| Ammonia (as N) | 1,535.000 | 675.000 |
| Total suspended solids | 172.800 | 138.200 |
| pH | () | () |
| Within the range of 7.5 to 10.0 at all times. | | |
(n) Zirconium chip crushing west air pollution control.
NSPS for the Primary Zirconium and Hafnium Subcategory
| Pollutant or pollutant property | Maximum for any 1 day | Maximum for monthly average |
| --- | --- | --- |
| | mg/kg (pounds per million pounds) of zirconium and hafnium produced | |
| Chromium (total) | 0.000 | 0.000 |
| Cyanide (total) | 0.000 | 0.000 |
| Lead | 0.000 | 0.000 |
| Nickel | 0.000 | 0.000 |
| Ammonia (as N) | 0.000 | 0.000 |
| Total suspended solids | 0.000 | 0.000 |
| pH | () | () |
| Within the range of 7.5 to 10.0 at all times. | | |
(o) Acid leachate from zirconium metal production.
NSPS for the Primary Zirconium and Hafnium Subcategory
| Pollutant or pollutant property | Maximum for any 1 day | Maximum for monthly average |
| --- | --- | --- |
| | mg/kg (pounds per million pounds) of pure zirconium produced | |
| Chromium (total) | 10.900 | 4.420 |
| Cyanide (total) | 5.893 | 2.357 |
| Lead | 8.250 | 3.831 |
| Nickel | 16.210 | 10.900 |
| Ammonia (as N) | 3,928.000 | 1,674.000 |
| Total suspended solids | 442.000 | 353.600 |
| pH | () | () |
| Within the range of 7.5 to 10.0 at all times. | | |
(p) Acid leachate from zirconium alloy production.
NSPS for the Primary Zirconium and Hafnium Subcategory
| Pollutant or pollutant property | Maximum for any 1 day | Maximum for monthly average |
| --- | --- | --- |
| | mg/kg (pounds per million pounds) of zirconium contained in alloys produced | |
| Chromium (total) | 5.835 | 2.366 |
| Cyanide (total) | 3.154 | 1.262 |
| Lead | 4.416 | 2.050 |
| Nickel | 8.674 | 5.835 |
| Ammonia (as N) | 2,102.000 | 895.800 |
| Total suspended solids | 236.600 | 189.300 |
| pH | () | () |
| Within the range of 7.5 to 10.0 at all times. | | |
(q) Leaching rinse water from zirconium metal production.
NSPS Limitations for the Primary Zirconium and Hafnium Subcategory
| Pollutant or pollutant property | Maximum for any 1 day | Maximum for monthly average |
| --- | --- | --- |
| | mg/kg (pounds per million pounds) of pure zirconium produced | |
| Chromium (total) | 21.810 | 8.840 |
| Cyanide (total) | 11.790 | 4.715 |
| Lead | 16.500 | 7.661 |
| Nickel | 32.410 | 21.810 |
| Ammonia (as N) | 7,856.000 | 3,453.000 |
| Total suspended solids | 884.000 | 707.200 |
| pH | () | () |
| Within the range of 7.5 to 10.0 at all times. | | |
(r) Leaching rinse water from zirconium alloy production.
NSPS for the Primary Zirconium and Hafnium Subcategory
| Pollutant or pollutant property | Maximum for any 1 day | Maximum for monthly average |
| --- | --- | --- |
| | mg/kg (pounds per million pounds) of zirconium contained in alloys produced | |
| Chromium (total) | 0.292 | 0.118 |
| Cyanide (total) | 0.158 | 0.063 |
| Lead | 0.221 | 0.103 |
| Nickel | 0.434 | 0.292 |
| Ammonia (as N) | 105.200 | 46.240 |
| Total suspended solids | 11.840 | 9.468 |
| pH | () | () |
| Within the range of 7.5 to 10.0 at all times. | | |