States may adopt WQS variances, as defined in § 131.3(o) . Such a WQS variance is subject to the provisions of this section and public participation requirements at § 131.20(b) . A WQS variance is a water quality standard subject to EPA review and approval or disapproval. (a)Applicability. (1) A WQS variance may be adopted for a permittee(s) or water body/waterbody segment(s), but only applies to the permittee(s) or water body/waterbody segment(s) specified in the WQS variance. (2) Where a State