40 CFR § 421.216 - Pretreatment standards for new sources.
---
identifier: "/us/cfr/t40/s421.216"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "40 CFR § 421.216 - Pretreatment standards for new sources."
title_number: 40
title_name: "Protection of Environment"
section_number: "421.216"
section_name: "Pretreatment standards 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"
---
# 421.216 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 molybdenum and rhenium process wastewater introduced into a POTW shall not exceed the following values:
(a) Molybdenum sulfide leachate.
PSNS for the Primary Molybdenum and Rhenium Subcategory
| Pollutant or pollutant property | Maximum for any 1 day | Maximum for monthly average |
| --- | --- | --- |
| | mg/kg (pounds per million pounds) of molybdenum sulfide leached | |
| Arsenic | 0.644 | 0.287 |
| Lead | 0.130 | 0.060 |
| Nickel | 0.255 | 0.171 |
| Selenium | 0.380 | 0.171 |
| Molybdenum | [Reserved] | [Reserved]. |
| Ammonia (as N) | 61.720 | 27.130 |
| Fluoride | 16.210 | 9.214 |
(b) Roaster SO<sub>2</sub> scrubber.
PSNS for the Primary Molybdenum and Rhenium Subcategory
| Pollutant or pollutant property | Maximum for any 1 day | Maximum for monthly average |
| --- | --- | --- |
| | mg/kg (pounds per million pounds) of molybdenum sulfide roasted | |
| Arsenic | 2.334 | 1.041 |
| Lead | 0.470 | 0.218 |
| Nickel | 0.924 | 0.621 |
| Selenium | 1.377 | 0.621 |
| Molybdenum | [Reserved] | [Reserved]. |
| Ammonia (as N) | 223.800 | 98.390 |
| Fluoride | 58.770 | 33.410 |
(c) Molybdic oxide leachate.
PSNS for the Primary Molybdenum and Rhenium Subcategory
| Pollutant or pollutant property | Maximum for any 1 day | Maximum for monthly average |
| --- | --- | --- |
| | mg/kg (pounds per million pounds) of molybdenum contained in molybdic oxide leached | |
| Arsenic | 16.100 | 7.182 |
| Lead | 3.244 | 1.506 |
| Nickel | 6.371 | 4.286 |
| Selenium | 9.499 | 4.286 |
| Molybdenum | [Reserved] | [Reserved]. |
| Ammonia (as N) | 1,544.000 | 678.800 |
| Fluoride | 405.400 | 230.500 |
(d) Hydrogen reduction furnace scrubber.
PSNS for the Primary Molybdenum and Rhenium Subcategory
| Pollutant or pollutant property | Maximum for any 1 day | Maximum for monthly average |
| --- | --- | --- |
| | mg/kg (pounds per million pounds) of molybdenum metal powder produced | |
| Arsenic | 3.183 | 1.420 |
| Lead | 0.641 | 0.298 |
| Nickel | 1.260 | 0.847 |
| Selenium | 1.878 | 0.847 |
| Molybdenum | [Reserved] | [Reserved]. |
| Ammonia (as N) | 305.300 | 134.200 |
| Fluoride | 80.150 | 45.570 |
(e) Depleted rhenium scrubbing solution.
PSNS for the Primary Molybdenum and Rhenium Subcategory
| Pollutant or pollutant property | Maximum for any 1 day | Maximum for monthly average |
| --- | --- | --- |
| | mg/kg (pounds per million pounds) of molybdenum sulfide roasted | |
| Arsenic | 0.995 | 0.444 |
| Lead | 0.201 | 0.093 |
| Nickel | 0.394 | 0.265 |
| Selenium | 0.587 | 0.265 |
| Molybdenum | [Reserved] | [Reserved]. |
| Ammonia (as N) | 95.440 | 41.960 |
| Fluoride | 25.060 | 14.250 |
[50 FR 38355, Sept. 20, 1985, as amended at 55 FR 31702, 31703, Aug. 3, 1990]