|(a) The burden of establishing that a PRP qualifies for any defenses to liability set forth in the Act, §361.275 or that a release is divisible as set forth in the Act, §361.276 lies with the PRP asserting such claim. (b) A PRP must demonstrate to the executive director its entitlement to a defense or claim under the Act, §361.275 or §361.276. The determination by the executive director of a PRP's request for limitation of liability under these sections of the Act is a discretionary act which does not entitle the PRP to an appeal to the commission or an adjudicatory hearing on such determination. (c) The executive director will not consider claims of divisibility until a site has been adequately characterized by a remedial investigation. (d) A determination by the executive director on a defense or claim asserted under the Act, §361.275 or §361.276 shall have no res judicata or
collateral estoppel effect on a PRP's ultimate liability for remediation of a facility as determined in subsequent commission proceedings or in district court.