Site Feedback

Title 40

Displaying title 40, up to date as of 10/14/2026. Title 40 was last amended 10/14/2026.
New Finding Aids are now available on eCFR.gov. The Parallel Table of Authorities, Subject Index, and Agency-prepared Indexes are now online! Learn more
eCFR Content

The Code of Federal Regulations (CFR) is the official legal print publication containing the codification of the general and permanent rules published in the Federal Register by the departments and agencies of the Federal Government. The Electronic Code of Federal Regulations (eCFR) is a continuously updated online version of the CFR. It is not an official legal edition of the CFR.

Learn more about the eCFR, its status, and the editorial process.

Subpart AA—Secondary Tin Subcategory

Source:

50 FR 38376, Sept. 20, 1985, unless otherwise noted.

§ 421.290 Applicability: Description of the secondary tin subcategory.

The provisions of this subpart are applicable to discharges resulting from the production of tin at secondary tin facilities utilizing either pyrometallurgical or hydrometallurgical processes to recover tin from secondary materials.

§ 421.291 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.

§ 421.292 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 technology currently available:

(a) Tin smelter SO2 scrubber.

BPT Limitations for the Secondary Tin Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of crude tapped tin metal produced
Arsenic 19.220 8.554
Lead 3.863 1.840
Iron 11.040 5.611
Tin 3.495 2.024
Total suspended solids 377.100 179.400
pH (1) (1)
1 Within the range of 7.5 to 10.0 at all times.

(b) Dealuminizing rinse.

BPT Limitations for the Secondary Tin Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of dealuminized scrap produced
Lead 0.015 0.007
Cyanide (total) 0.010 0.004
Fluoride 1.225 0.700
Tin 0.013 0.008
Total suspended solids 1.435 0.683
pH (1) (1)
1 Within the range of 7.5 to 10.0 at all times.

(c) Tin mud acid neutralization filtrate.

BPT Limitations for the Secondary Tin Subcategory

Pollutant or pollutant property Minimum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of neutralized, dewatered tin mud produced
Lead 2.120 1.009
Cyanide (total) 1.464 0.606
Fluoride 176.600 100.400
Tin 1.918 1.110
Total suspended solids 206.900 98.420
pH (1) (1)
1 Within the range of 7.5 to 10.0 at all times.

(d) Tin hydroxide wash.

BPT Limitations for the Secondary Tin Subcategory

Pollutant or pollutant property Minimum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of tin hydroxide washed
Lead 5.020 2.391
Cyanide (total) 3.466 1.434
Fluoride 418.400 237.900
Tin 4.542 2.630
Total suspended solids 490.100 233.100
pH (1) (1)
1 Within the range of 7.5 to 10.0 at all times.

(e) Spent electrowinning solution from new scrap.

BPT Limitations for the Secondary Tin Subcategory

Pollutant or pollutant property Minimum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of cathode tin produced
Lead 7.056 3.360
Cyanide (total) 4.872 2.016
Fluoride 588.000 334.300
Tin 6.384 3.696
Total suspended solids 688.800 327.600
pH (1) (1)
1 Within the range of 7.5 to 10.0 at all times.

(f) Spent electrowinning solution from municipal solid waste.

BPT Limitations for the Secondary Tin Subcategory

Pollutant or pollutant property Minimum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of MSW scrap used as raw material
Lead 0.050 0.024
Cyanide (total) 0.035 0.014
Fluoride 4.165 2.368
Tin 0.045 0.026
Total suspended solids 4.879 2.321
pH (1) (1)
1 Within the range of 7.5 to 10.0 at all times.

(g) Tin hydroxide supernatant from scrap.

BPT Limitations for the Secondary Tin Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of tin metal recovered from scrap
Lead 23.370 11.130
Cyanide (total) 16.140 6.677
Fluoride 1,947.000 1,107.000
Tin 21.140 12.240
Total suspended solids 2,281.000 1,085.000
pH (1) (1)
1 Within the range of 7.5 to 10.0 at all times.

(h) Tin hydroxide supernatant from plating solutions and sludges.

BPT Limitations for the Secondary Tin Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of tin metal recovered from plating solutions and sludges
Lead 48.30 23.00
Cyanide (total) 33.35 13.80
Fluoride 4,025.00 2,289.00
Tin 43.70 25.30
Total suspended solids 4,715.00 2,243.00
pH (1) (1)
1 Within the range of 7.5 to 10.0 at all times.

(i) Tin hydroxide filtrate.

BPT Limitations for the Secondary Tin Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of tin metal produced
Lead 10.520 5.009
Cyanide (total) 7.263 3.005
Fluoride 876.500 498.400
Tin 9.517 5.510
Total suspended solids 1,027.000 488.400
pH (1) (1)
1 Within the range of 7.5 to 10.0 at all times.

§ 421.293 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) Tin smelter SO2 scrubber.

BAT Limitations for the Secondary Tin Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of crude tapped tin produced
Arsenic 12.790 5.703
Lead 2.575 1.196
Iron 11.040 5.611
Tin 3.495 2.024

(b) Dealuminizing rinse.

BAT Limitations for the Secondary Tin Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of dealuminized scrap produced
Lead 0.010 0.005
Cyanide (total) 0.007 0.003
Fluoride 1.225 0.697
Tin 0.013 0.008

(c) Tin mud acid neutralization filtrate.

BAT Limitations for the Secondary Tin Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of neutralized dewatered tin mud produced
Lead 1.413 0.656
Cyanide (total) 1.009 0.404
Fluoride 176.600 100.400
Tin 1.918 1.110

(d) Tin hydroxide wash.

BAT Limitations for the Secondary Tin Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of tin hydroxide washed
Lead 3.347 1.554
Cyanide (total) 2.391 0.956
Fluoride 418.400 237.900
Tin 4.542 2.630

(e) Spent electrowinning solution from new scrap.

BAT Limitations for the Secondary Tin Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of cathode tin produced
Lead 4.704 2.184
Cyanide (total) 3.360 1.344
Fluoride 588.000 334.300
Tin 6.384 3.696

(f) Spent electrowinning solution from municipal solid waste.

BAT Limitations for the Secondary Tin Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of MSW scrap used as raw material
Lead 0.033 0.015
Cyanide (total) 0.024 0.010
Fluoride 4.165 2.368
Tin 0.045 0.026

(g) Tin hydroxide supernatant from scrap.

BAT Limitations for the Secondary Tin Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of tin metal recovered from scrap
Lead 15.580 7.233
Cyanide (total) 11.130 4.451
Fluoride 1,947.000 1,107.000
Tin 21.140 21.240

(h) Tin hydroxide supernatant from plating solutions and sludges.

BAT Limitations for the Secondary Tin Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of tin metal recovered from plating solutions and sludges
Lead 32.20 14.95
Cyanide (total) 23.00 9.20
Fluoride 4,025.00 2,289.00
Tin 43.70 25.30

(i) Tin hydroxide filtrate.

BAT Limitations for the Secondary Tin Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of tin metal produced
Lead 7.012 3.256
Cyanide (total) 5.009 2.004
Fluoride 876.500 498.400
Tin 9.517 5.510

§ 421.294 Standards of performance for new sources.

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

(a) Tin smelter SO2 scrubber.

NSPS for the Secondary Tin Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of crude tapped tin produced
Arsenic 12.790 5.703
Lead 2.575 1.196
Iron 11.040 5.611
Tin 3.495 2.024
Total suspended solids 138.000 110.400
pH (1) (1)
1 Within the range of 7.5 to 10.0 at all times.

(b) Dealuminizing rinse.

NSPS for the Secondary Tin Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of dealuminized scrap produced
Lead 0.010 0.005
Cyanide (total) 0.007 0.003
Fluoride 1.225 0.697
Tin 0.013 0.008
Total suspended solids 0.525 0.420
pH (1) (1)
1 Within the range of 7.5 to 10.0 at all times.

(c) Tin mud acid neutralization filtrate.

NSPS for the Secondary Tin Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of neutralized dewatered tin mud produced
Lead 1.413 0.656
Cyanide (total) 1.009 0.404
Fluoride 176.600 100.400
Tin 1.918 1.110
Total suspended solids 75.710 60.560
pH (1) (1)
1 Within the range of 7.5 to 10.0 at all times.

(d) Tin hydroxide wash.

NSPS for the Secondary Tin Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of tin hydroxide washed
Lead 3.347 1.554
Cyanide (total) 2.391 0.956
Fluoride 418.400 237.900
Tin 4.542 2.630
Total suspended solids 179.300 143.400
pH (1) (1)
1 Within the range of 7.5 to 10.0 at all times.

(e) Spent electrowinning solution from new scrap.

NSPS for the Secondary Tin Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of cathode tin produced
Lead 4.704 2.184
Cyanide (total) 3.360 1.344
Fluoride 588.000 334.300
Tin 6.384 3.696
Total suspended solids 252.000 201.600
pH (1) (1)
1 Within the range of 7.5 to 10.0 at all times.

(f) Spent electrowinning solution from municipal solid waste.

NSPS for the Secondary Tin Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of MSW scrap used as raw material
Lead 0.033 0.015
Cyanide (total) 0.024 0.010
Fluoride 4.165 2.368
Tin 0.045 0.026
Total suspended solids 1.785 1.428
pH (1) (1)
1 Within the range of 7.5 to 10.0 at all times.

(g) Tin hydroxide supernatant from scrap.

NSPS for the Secondary Tin Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of tin metal recovered from scrap
Lead 15.580 7.233
Cyanide (total) 11.130 4.451
Fluoride 1,947.000 1,107.000
Tin 21.140 12.240
Total suspended solids 834.600 667.700
pH (1) (1)
1 Within the range of 7.5 to 10.0 at all times.

(h) Tin hydroxide supernatant from plating solutions and sludges.

NSPS for the Secondary Tin Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of tin metal recovered from plating solutions and sludges
Lead 32.20 14.95
Cyanide (total) 23.00 9.20
Fluoride 4,025.00 2,289.00
Tin 43.70 25.30
Total suspended solids 1,725.00 1,380.00
pH (1) (1)
1 Within the range of 7.5 to 10.0 at all times.

(i) Tin hydroxide filtrate.

NSPS for the Secondary Tin Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of tin metal produced
Lead 7.012 3.256
Cyanide (total) 5.009 2.004
Fluoride 876.500 498.400
Tin 9.517 5.510
Total suspended solids 375.700 300.500
pH (1) (1)
1 Within the range of 7.5 to 10.0 at all times.

§ 421.295 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 must comply with 40 CFR part 403 and achieve the following pretreatment standards for existing sources. The mass of wastewater pollutants in secondary tin process wastewater introduced into a POTW must not exceed the following values:

(a) Tin smelter SO2 scrubber.

PSES for the Secondary Tin Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of crude tapped tin produced
Arsenic 12.790 5.703
Lead 2.575 1.196
Iron 11.040 5.611
Tin 3.495 2.024

(b) Dealuminizing rinse.

PSES for the Secondary Tin Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of dealuminized scrap produced
Lead 0.010 0.005
Cyanide (total) 0.007 0.003
Fluoride 1.225 0.697
Tin 0.013 0.008

(c) Tin mud acid neutralization filtrate.

PSES for the Secondary Tin Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of neutralized dewatered tin mud produced
Lead 1.413 0.656
Cyanide (total) 1.009 0.404
Fluoride 176.600 100.400
Tin 1.918 1.110

(d) Tin hydroxide wash.

PSES for the Secondary Tin Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of tin hydroxide washed
Lead 3.347 1.554
Cyanide (total) 2.391 0.956
Fluoride 418.400 237.900
Tin 4.542 2.630

(e) Spent electrowinning solution from new scrap.

PSES for the Secondary Tin Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of cathode tin produced
Lead 4.704 2.184
Cyanide (total) 3.360 1.344
Fluoride 588.000 334.300
Tin 6.384 3.696

(f) Spent electrowinning solution from municipal solid waste.

PSES for the Secondary Tin Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of MSW scrap used as raw material
Lead 0.033 0.015
Cyanide (total) 0.024 0.010
Fluoride 4.165 2.368
Tin 0.045 0.026

(g) Tin hydroxide supernatant from scrap.

PSES for the Secondary Tin Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of tin metal recovered from scrap
Lead 15.580 7.233
Cyanide (total) 11.130 4.451
Fluoride 1,947.000 1,107.000
Tin 21.140 12.240

(h) Tin hydroxide supernatant from plating solutions and sludges.

PSES for the Secondary Tin Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of tin metal recovered from plating solutions and sludges
Lead 32.20 14.95
Cyanide (total) 23.00 9.20
Fluoride 4,025.00 2,289.00
Tin 43.70 25.30

(i) Tin hydroxide filtrate.

PSES for the Secondary Tin Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of tin metal produced
Lead 7.012 3.256
Cyanide (total) 5.009 2.004
Fluoride 876.500 498.400
Tin 9.517 5.510

§ 421.296 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 secondary tin process wastewater introduced into a POTW shall not exceed the following values:

(a) Tin smelter SO2 scrubber.

PSNS for the Secondary Tin Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of crude tapped tin produced
Arsenic 12.790 5.703
Lead 2.575 1.196
Iron 11.040 5.611
Tin 3.495 2.024

(b) Dealuminizing rinse.

PSNS for the Secondary Tin Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of dealuminized scrap produced
Lead 0.010 0.005
Cyanide (total) 0.007 0.003
Fluoride 1.225 0.697
Tin 0.013 0.008

(c) Tin mud acid neutralization filtrate.

PSNS for the Secondary Tin Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million of pounds) of neutralized dewatered tin mud produced
Lead 1.413 0.656
Cyanide (total) 1.009 0.404
Fluoride 176.600 100.400
Tin 1.918 1.110

(d) Tin hydroxide wash.

PSNS for the Secondary Tin Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of tin hydroxide washed
Lead 3.347 1.554
Cyanide (total) 2.391 0.956
Fluoride 418.400 237.900
Tin 4.542 2.630

(e) Spent electrowinning solution from new scrap.

PSNS for the Secondary Tin Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of cathode tin produced
Lead 4.704 2.184
Cyanide (total) 3.360 1.344
Fluoride 588.000 334.300
Tin 6.384 3.696

(f) Spent electrowinning solution from municipal solid waste.

PSNS for the Secondary Tin Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of MSW scrap used as raw material
Lead 0.033 0.015
Cyanide (total) 0.024 0.010
Fluoride 4.165 2.368
Tin 0.045 0.026

(g) Tin hydroxide supernatant from scrap.

PSNS for the Secondary Tin Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of tin metal recovered from scrap
Lead 15.580 7.233
Cyanide (total) 11.130 4.451
Fluoride 1,947.000 1,107.000
Tin 21.140 12.240

(h) Tin hydroxide supernatant from plating solutions and ludges.

PSNS for the Secondary Tin Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of tin metal recovered from plating solutions and sludges
Lead 32.20 14.95
Cyanide (total) 23.00 9.20
Fluoride 4,025.00 2,289.00
Tin 43.70 25.30

(i) Tin hydroxide filtrate.

PSNS for the Secondary Tin Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of tin metal produced
Lead 7.012 3.256
Cyanide (total) 5.009 2.004
Fluoride 876.500 498.400
Tin 9.517 5.510

§ 421.297 [Reserved]