CFR > Title 40 - Protection of Environment > CHAPTER I—ENVIRONMENTAL PROTECTION AGENCY > SUBCHAPTER N—EFFLUENT GUIDELINES AND STANDARDS (Parts 400–471) > PART 429—TIMBER PRODUCTS PROCESSING POINT SOURCE CATEGORY > SUBPART A—Barking Subcategory (§429.20 to §429.26) > 429.21—Effluent limitations representing the degree of effluent reduction attainable by the application of the best practicable control technology currently available (BPT).

429.21—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):
(a) The following limitations apply to all mechanical barking installations: There shall be no discharge of process wastewater pollutants into navigable waters.
(b) The following limitations constitute the maximum permissible discharge for hydraulic barking installations:
Subpart A
Pollutant or pollutant property BPT effluent limitations
Maximum for any 1 day Average of daily values for 30 consecutive days
Metric units (kilograms per cubic meter of production)
BOD5 1.5 0.5
TSS 6.9 2.3
pH (1) (1)
English units (pounds per cubic foot of production)
BOD5 0.09 0.03
TSS 0.431 0.144
pH (1) (1)
1 Within the range 6.0 to 9.0 at all times.
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):
(a) The following limitations apply to all mechanical barking installations: There shall be no discharge of process wastewater pollutants into navigable waters.
(b) The following limitations constitute the maximum permissible discharge for hydraulic barking installations:
Subpart A
Pollutant or pollutant property BPT effluent limitations
Maximum for any 1 day Average of daily values for 30 consecutive days
Metric units (kilograms per cubic meter of production)
BOD5 1.5 0.5
TSS 6.9 2.3
pH (1) (1)
English units (pounds per cubic foot of production)
BOD5 0.09 0.03
TSS 0.431 0.144
pH (1) (1)
1 Within the range 6.0 to 9.0 at all times.