Statutes, codes, and regulations
Code of Federal Regulations
Title 40 - PROTECTION OF ENVIRONMENTChapter I - ENVIRONMENTAL PROTECTION AGENCYSubchapter N - EFFLUENT GUIDELINES AND STANDARDSPart 421 - NONFERROUS METALS MANUFACTURING POINT SOURCE CATEGORY
Subpart W - PRIMARY PRECIOUS METALS AND MERCURY SUBCATEGORY
Section 421.253 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the application of the best available technology economically achievable

40 C.F.R. § 421.253

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Current through September 30, 2024
Section 421.253 - 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) Smelter wet air pollution control.

BAT Limitations for the Primary Precious Metals and Mercury Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of gold and silver smelted
Lead0.3640.169
Mercury0.1950.078
Silver0.3770.156
Zinc1.3260.546
Gold0.130

(b) Silver chloride reduction spent solution.

BAT Limitations for the Primary Precious Metals and Mercury Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver reduced in solution
Lead0.1120.052
Mercury0.0600.024
Silver0.1160.048
Zinc0.4080.168
Gold0.040

(c) Electrolytic cells wet air pollution control.

BAT Limitations for the Primary Precious Metals and Mercury Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of gold refined electrolytically
Lead5.5442.574
Mercury2.9701.188
Silver5.7422.376
Zinc20.2008.316
Gold1.980

(d) Electrolyte preparation wet air pollution control.

BAT Limitations for the Primary Precious Metals and Mercury Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/troy ounce of silver in electrolyte produced
Lead0.0140.007
Mercury0.0080.003
Silver0.0150.006
Zinc0.0510.021
Gold0.005

(e) Calciner Wet Air Pollution Control.

BAT Limitations for the Primary Precious Metals and Mercury Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of mercury condensed
Lead6.1602.860
Mercury3.3001.320
Silver6.3802.640
Zinc22.4409.240
Gold2.200

(f) Calcine quench water.

BAT Limitations for the Primary Precious Metals and Mercury Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of mercury condensed
Lead4.9282.288
Mercury2.6401.056
Silver5.1042.112
Zinc17.9507.392
Gold1.760

(g) Calciner stack gas contact cooling water.

BAT Limitations for the Primary Precious Metals and Mercury Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of mercury condensed
Lead1.1620.540
Mercury0.6230.249
Silver1.2040.498
Zinc4.2331.743
Gold0.415

(h) Condenser blowdown.

BAT Limitations for the Primary Precious Metals and Mercury Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of mercury condensed
Lead3.8641.794
Mercury2.0700.828
Silver4.0021.656
Zinc14.0805.796
Gold1.380

(i) Mercury cleaning bath water.

BAT Limitations for the Primary Precious Metals and Mercury Subcategory

Pollutant or pollutant property Maximum for any 1 day Maximum for monthly average
mg/kg (pounds per million pounds) of mercury condensed
Lead0.3920.182
Mercury0.2100.084
Silver0.4060.168
Zinc1.4280.588
Gold0.140

40 C.F.R. §421.253