CFR > Title 40 - Protection of Environment > CHAPTER I—ENVIRONMENTAL PROTECTION AGENCY > SUBCHAPTER N—EFFLUENT GUIDELINES AND STANDARDS (Parts 400–471) > PART 421—NONFERROUS METALS MANUFACTURING POINT SOURCE CATEGORY > SUBPART S—Primary Molybdenum and Rhenium Subcategory (§421.210 to §421.217) > 421.212—Effluent limitations guidelines representing the degree of effluent reduction attainable by the application of the best practicable control technology currently available.

421.212—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 limitation representing the degree of effluent reduction attainable by the application of the best practicable technology currently available:
(a) Molybdenum sulfide leachate.
BPT Limitations for the Primary Molybdenum Rhenium Subcategory
Pollutant or pollutant property Maximum for any 1 day Maximum monthly average
mg/kg (pounds per million pounds) of molybdenum sulfide leached
Arsenic 0.968 0.431
Lead 0.195 0.093
Nickle 0.889 0.588
Selenium 0.570 0.255
Molybdenum [Reserved] [Reserved].
Ammonia (as N) 61.720 27.130
Fluoride 16.210 9.214
Total suspended solids 18.980 9.029
pH (1) (1)
1 Within the range of 7.5 to 10.0 at all times.
(b) Roaster SO2 scrubber.
BPT Limitations for the Primary Molybdenum and Rhenium Subcategory
Pollutant of pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of molybdenum sulfide roasted
Arsenic 3.509 1.561
Lead 0.705 0.336
Nickel 3.224 2.133
Selenium 2.065 0.924
Molybdenum [Reserved] [Reserved].
Ammonia (as N) 223.800 98.390
Fluoride 58.770 33.410
Total suspended solids 68.840 32.740
pH (1) (1)
1 Within the range of 7.5 to 10.0 at all times.
(c) Molybdic oxide leachate.
BPT Limitations 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 24.210 10.770
Lead 4.865 2.317
Nickel 22.240 14.710
Selenium 14.250 6.371
Molybdenum [Reserved] [Reserved]
Ammonia (as N) 1,544.000 678.800
Flouride 405.400 230.500
Total suspended solids 474.900 225.900
pH (1) (1)
1 Within the range of 7.5 to 10.0 at all times.
(d) Hydrogen reduction furnace scrubber.
BPT Limitations 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 47.860 21.300
Lead 9.617 4.580
Nickel 43.970 29.080
Selenium 28.170 12.600
Molybdenum [Reserved] [Reserved]
Ammonia (as N) 3,052.000 1,342.000
Fluoride 801.400 455.700
Total suspended solids 938.800 446.500
pH (1) (1)
1 Within the range of 7.5 to 10.0 at all times.
(e) Depleted rhenium scrubbing solution.
BPT Limitations 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 1.497 0.666
Lead 0.301 0.143
Nickel 1.375 0.909
Selenium 0.881 0.394
Molybdenum [Reserved] [Reserved]
Ammonia (as N) 95.440 41.960
Fluoride 25.060 14.250
Total suspended solids 29.360 13.960
pH (1) (1)
1 Within the range of 7.5 to 10.0 at all times.
[50 FR 38355, Sept. 20, 1985, as amended at 55 FR 31701, Aug. 3, 1990]