This subpart applies to discharges to waters of the United States and to the introduction of process wastewater pollutants into publicly owned treatment works from any plant which produces hardboard products using the wet matting process for forming the board mat.

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 plants which produce smooth-one-side (S1S) hardboard:

(b) The following limitations apply to plants which produce smooth-two-sides (S2S) hardboard:

For purpose of this new source performance standard only, “new source” means a source which is constructed at a site at which no other source covered by this part is located. Any new source subject to this subpart must achieve the following new source performance standards (NSPS): There shall be no discharge of process wastewater pollutants into navigable waters.

Any existing source subject to this subpart which introduces process wastewater pollutants into a publicly owned treatment works must comply with 40 CFR part 403.

Any new source subject to this subpart which introduces process wastewater pollutants into a publicly owned treatment works must comply with 40 CFR part 403.