In United States v. Atlantic Research Corp., 551 U.S. 128, 139, 127 S.Ct. 2331, 168 L.Ed.2d 28 (2007), the Supreme Court endeavored to clarify the relationship between 107(a) of CERCLA, 42 U.S.C. 9607 cost recovery claims and 113(f) contribution claims, noting that those remedies are distinct. The Supreme Court has held that " 107(a) permits a PRP to recover only the costs it has `incurred' in cleaning up a site." Atl. Research Corp., 551 U.S. at 139, 127 S.Ct. 2331 (quoting 42 U.S.C. 9607(a)(4)(B)). The Court has further explained that, "when a party pays to satisfy a settlement agreement or a court judgment, it does not incur its own costs of response. Rather, it reimburses other parties for costs that those parties incurred." Id. The Supreme Court, in Atlantic Research, left open the precise question raised by Carpenter's argument, namely, whether plaintiffs in the position of Cytec, Ford, SPS, and TI can bring a 107(a) claim in addition to a 113(f) claim. The Court said: "We do not suggest that 107(a)(4)(B) and 113(f) have no overlap at all. For instance, we recognize that a PRP may sustain expenses pursuant to a consent decree following a suit under ... 107(a). In such a case, the PRP does not incur costs voluntarily but does not reimburse the costs of another party. We do not decide whether these compelled costs of response are recoverable under 113(f), 107(a), or both. For our purposes, it suffices to demonstrate that costs incurred voluntarily are recoverable only by way of 107(a)(4)(B), and costs of reimbursement to another person pursuant to a legal judgment or settlement are recoverable only under 113(f). Thus, at a minimum, neither remedy swallows the other...." Id. In Atlantic Research, immediately after setting forth this unanswered question, and after suggesting that there is, in fact, some "overlap" between 107(a) and 113(f), the Supreme Court stated that "a defendant PRP in such a 107(a) joint and several liability suit could blunt any inequitable distribution of costs by filing a 113(f) counterclaim." 551 U.S. at 140, 127 S.Ct. 2331. The Court explained that any fear that "PRPs will eschew equitable apportionment under 113(f) in favor of joint and several liability under 107(a)" is mitigated by the fact that "a 113(f) counterclaim would necessitate the equitable apportionment of costs among the liable parties, including the PRP that filed the 107(a) action." Id. at 138, 40, 127 S.Ct. 2331.