(a) If a State process provides a State process recommendation to the Agency through the State's single point of contact, the Administrator either:

(1) Accepts the recommendation;

(2) reaches a mutually agreeable solution with the State process; or

(3) Provides the single point of contact with such written explanation of the decision, as the Administrator, in his or her discretion, deems appropriate. The Administrator may also supplement the written explanation by providing the explanation to the single point of contact by telephone, other telecommunication, or other means.

(b) In any explanation under paragraph (a)(3) of this section, the Administrator informs the single point of contact that:

(1) EPA will not implement its decision for at least ten days after the single point of contact receives the explanation; or

(2) The Administrator has reviewed the decision and determined that, because of unusual circumstances, the waiting period of at least ten days is not feasible.

(c) For purposes of computing the waiting period under paragraph (b)(1) of this section, a single point of contact is presumed to have received written notification 5 days after the date of mailing of such notification.