Section 300.500 - General(a) EPA shall ensure meaningful and substantial state involvement in hazardous substance response as specified in this subpart. EPA shall provide an opportunity for state participation in removal, pre-remedial, remedial, and enforcement response activities. EPA shall encourage states to enter into an EPA/state Superfund Memorandum of Agreement (SMOA) under § 300.505 to increase state involvement and strengthen the EPA/state partnership.(b) EPA shall encourage states to participate in Fund-financed response in two ways. Pursuant to § 300.515(a) , states may either assume the lead through a cooperative agreement for the response action or may be the support agency in EPA-lead remedial response. Section 300.515 sets forth requirements for state involvement in EPA-lead remedial and enforcement response and also addresses comparable requirements for EPA involvement in state-lead remedial and enforcement response. Section 300.520 specifies requirements for state involvement in EPA-lead enforcement negotiations. Section 300.525 specifies requirements for state involvement in removal actions. In addition to the requirements set forth in this subpart, 40 CFR part 35, subpart O, "Cooperative Agreements and Superfund State Contracts for Superfund Response Actions," contains further requirements for state participation during response.