StacksVerified U.S. regulatory reference

40 CFR §63.444

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
  1. (a)The owner or operator of each sulfite process subject to the requirements of this subpart shall control the total HAP emissions from the following equipment systems as specified in paragraphs (b) and (c) of this section.
    1. (1)At existing sulfite affected sources, the total HAP emissions from the following equipment systems shall be controlled:
      1. (i)Each digester system vent;
      2. (ii)Each evaporator system vent; and
      3. (iii)Each pulp washing system.
    2. (2)At new affected sources, the total HAP emissions from the equipment systems listed in paragraph (a)(1) of this section and the following equipment shall be controlled:
      1. (i)Each weak liquor storage tank;
      2. (ii)Each strong liquor storage tank; and
      3. (iii)Each acid condensate storage tank.
  2. (b)Equipment listed in paragraph (a) of this section shall be enclosed and vented into a closed-vent system and routed to a control device that meets the requirements specified in paragraph (c) of this section. The enclosures and closed-vent system shall meet the requirements specified in § 63.450. Emissions from equipment listed in paragraph (a) of this section that is not necessary to be reduced to meet paragraph (c) of this section is not required to be routed to a control device.
  3. (c)The total HAP emissions from both the equipment systems listed in paragraph (a) of this section and the vents, wastewater, and condensate streams from the control device used to reduce HAP emissions, shall be controlled as follows.
    1. (1)Each calcium-based or sodium-based sulfite pulping process shall:
      1. (i)Emit no more than 0.44 kilograms of total HAP or methanol per megagram (0.89 pounds per ton) of ODP; or
      2. (ii)Remove 92 percent or more by weight of the total HAP or methanol.
    2. (2)Each magnesium-based or ammonium-based sulfite pulping process shall:
      1. (i)Emit no more than 1.1 kilograms of total HAP or methanol per megagram (2.2 pounds per ton) of ODP; or
      2. (ii)Remove 87 percent or more by weight of the total HAP or methanol.