40 CFR § 142.310
How can a person served by the public water system obtain EPA review of a State proposed small system variance?
June 9, 2020
(a) Any person served by the public water system may petition the Administrator to object to the granting of a small system variance within 30 days after a State proposes to grant a small system variance for a public water system.
(b) The Administrator must respond to a petition filed by any person served by the public water system and determine whether to object to the small system variance under §142.311, no later than 60 days after the receipt of the petition.