Section 63.687 - Standards: Surface impoundments(a) The provisions of this section apply to the control of air emissions from surface impoundments for which § 63.683(b)(1)(i) of this subpart references the use of this section for such air emission control.(b) The owner or operator shall control air emissions from each surface impoundment subject to this section by using one of the following:(1) A floating membrane cover in accordance with the applicable provisions specified in subpart QQ of this part-National Emission Standards for Surface Impoundments, except that §§ 63.942(c)(2) and (3) and 63.943(c)(2) shall not apply for the purposes of this subpart; or(2) A cover that is vented through a closed-vent system to a control device in accordance with all applicable provisions specified in subpart QQ of this part-National Emission Standards for Surface Impoundments, except that §§ 63.942(c)(2) and (3) and 63.943(c)(2) shall not apply for the purposes of this subpart.61 FR 34158, July 1, 1996, as amended at 64 FR 38969, July 20, 1999; 80 FR 14274 , Mar. 18, 2015