Regulations last checked for updates: Jun 01, 2024

Title 40 - Protection of Environment last revised: May 30, 2024
§ 425.20 - Applicability; description of the hair save, chrome tan, retan-wet finish subcategory.

The provisions of this subpart are applicable to process wastewater discharges resulting from any tannery which processes raw or cured cattle or cattle-like hides into finished leather by hair save unhairing, chrome tanning, and retan-wet finishing.

§ 425.21 - Effluent limitations representing the degree of effluent reduction attainable by the application of the best practicable control technology currently available (BPT).

Except as provided in 40 CFR 125.30 through 125.32, any existing point source subject to this subpart must achieve the following effluent limitations representing the degree of effluent reduction attainable by the application of the best practicable control technology currently available (BPT):

Pollutant or pollutant property BPT limitations
Maximum for any 1 day Maximum for monthly average
Kg/kkg (or pound per 1,000 lb) of raw material
BOD58.23.7
TSS11.85.4
Oil and grease3.41.5
Total chromium0.210.08
pH( 1)( 1)

1 Within the range 6.0 to 9.0.

§ 425.22 - Effluent limitations representing the degree of effluent reduction attainable by the application of the best conventional pollutant control technology (BCT).

Except as provided in 40 CFR 125.30 through 125.32, any existing point source subject to this subpart must achieve the following effluent limitations representing the degree of effluent reduction attainable by the application of the best conventional pollutant control technology (BCT): The effluent limitations are those for BOD5, TSS, Oil and Grease, and pH contained in § 425.21.

§ 425.23 - Effluent limitations representing the degree of effluent reduction attainable by the application of the best available technology economically achievable (BAT).

Except as provided in 40 CFR 125.30 through 125.32, any existing point source subject to this subpart must achieve the following effluent limitations representing the degree of effluent reduction attainable by the application of the best available technology economically achievable (BAT): The effluent limitations are those for Total Chromium contained in § 425.21.

§ 425.24 - New source performance standards (NSPS).

Any new source subject to this subpart must achieve the following new source performance standards (NSPS):

Pollutant or pollutant property NSPS
Maximum for any 1 day Maximum for monthly average
Kg/kkg (or pound per 1,000 lb) of raw material
BOD56.93.1
TSS9.94.5
Oil and grease2.91.3
Total chromium0.180.06
pH( 1)( 1)

1 Within the range 6.0 to 9.0

§ 425.25 - Pretreatment standards for existing sources (PSES).

Except as provided in § 425.04 and 40 CFR 403.7 and 403.13, any existing source subject to this subpart that introduces process wastewater pollutants into a publicly owned treatment works must comply with 40 CFR part 403, and achieve the following pretreatment standards:

Pollutant or pollutant property PSES
Maximum for any 1 day Maximum for monthly average
Milligrams per liter (mg/l)
Sulfide24
Total Chromium128
pH( 1)( 1)

1 Not less than 7.0.

[47 FR 52870, Nov. 23, 1982, as amended at 61 FR 35685, July 8, 1996]
§ 425.26 - Pretreatment standards for new sources (PSNS).

Except as provided in 40 CFR 403.7 and 425.04, any new source subject to this subpart that introduces process wastewater pollutants into a publicly owned treatment works must comply with 40 CFR part 403, and achieve the pretreatment standards contained in § 425.25.

authority: 33 U.S.C. 1311,1314,c,e, 1316 (b) andc, 1317 (b) andc,1318
source: 47 FR 52870, Nov. 23, 1982, unless otherwise noted.
cite as: 40 CFR 425.23