Within 60 days after completion of the established post-closure care period, the owner or operator must submit to the Agency, by registered or certified mail, a certification that the post-closure care period for the unit was performed in compliance with the specifications in the approved post-closure plan. The certification must be signed by the owner or operator and an independent registered professional engineer. Documentation supporting the independent registered professional engineer's certification must be furnished to the Agency upon request.
Ill. Admin. Code tit. 35, § 616.306