TJOFLAT, Circuit Judge:

This appeal arises out of a multi-district litigation, in which multiple plaintiffs and their family members allege that they experienced various health problems after being exposed to toxic substances in the drinking water while living at Camp Lejeune, a military base in North Carolina. The plaintiffs brought this action against the United States under the Federal Tort Claims Act, 28 U.S.C. §§ 2671-2680. The United States moved to dismiss the case, arguing that the North Carolina statute of repose, which provided that "no cause of action shall accrue more than 10 years from the last act or omission of the defendant giving rise to the cause of action," N.C. Gen.Stat. § 1-52(16) (2010), precluded the plaintiffs from bringing this case.1

The District Court disagreed, concluding that a provision of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), 42 U.S.C. § 9658,2 preempted North Carolina's statute of repose. The court separately ruled that North Carolina's statute of repose does not contain an exception for latent diseases.

The District Court then certified two questions for interlocutory appeal,3 and this court permitted the appeal. The two questions presented are (I) whether CERCLA preempts the North Carolina statute of repose, and (II) whether the North Carolina statute of repose contains an exception for latent diseases. We address each question in turn.

I.

After the parties briefed this case, but before oral argument, the Supreme Court granted a petition for a writ of certiorari in a separate case out of the Fourth Circuit, which presented the question of whether CERCLA preempts North Carolina's statute of repose.4 On June 9, 2014, the Court determined that CERCLA, specifically 42 U.S.C. § 9658, does not preempt North Carolina's statute of repose. See generally CTS Corp. v. Waldburger, ___ U.S. ___, 134 S.Ct. 2175, 189 L.Ed.2d 62 (2014). Thus, we have the answer to the first question presented in this interlocutory appeal. CERCLA does not preempt North Carolina's statute of repose.

II.

We must, therefore, turn to the second question presented in this appeal, whether the North Carolina statute of repose includes an exception for latent diseases. At the time the plaintiffs brought this action, the statute of repose provided:

N.C. Gen.Stat. § 1-52(16) (2010). On its face, the text of the statute contains no exception for latent diseases, and no other North Carolina statute excepts latent diseases from the statute of repose. The plain text of the statute is unambiguous.5

Shortly after the Supreme Court decided Waldburger, however, the Governor of North Carolina approved Session Law 2014-17, which amended the statute of repose. The General Assembly also passed, and the Governor signed, Session Law 2014-44, which made several technical amendments to Session Law 2014-17.6 We then requested supplemental briefing from the parties on the following question: Whether, in light of the enactment of N.C. Session Laws 2014-17 and 2014-44, the plaintiffs' actions are barred by North Carolina's statute of repose (N.C.Gen.Stat. § 1-52(16))?7

The statute of repose now reads:

N.C. Gen.Stat. Ann. § 1-52(16) (West 2014) (emphasis added). The session law added a new section to the North Carolina General Statutes, § 130A-26.3, which provides: "The 10-year period set forth in G.S. 1-52(16) shall not be construed to bar an action for personal injury, or property damages caused or contributed to by ... the consumption, exposure, or use of water supplied from groundwater contaminated by a hazardous substance, pollutant, or contaminant." N.C. Gen.Stat. Ann. § 130A-26.3.8

The General Assembly expressly made Session Law 2014-44 apply to actions "filed, arising, or pending" on or after June 20, 2014, the statute's effective date. N.C. Sess. L. 2014-44, § 1(c) (amending N.C. Sess. L. 2014-17, § 4). Under the law, an action is pending "if there has been no final disposition with prejudice and mandate issued against that plaintiff issued by the highest court of competent jurisdiction where the claim was timely filed or appealed as to all the plaintiff's claims for relief to which this act otherwise applies." Id. In this case, the United States Supreme Court is the highest court of competent jurisdiction, and it has not issued a final disposition with prejudice, nor has a mandate issued from that Court. As such, the amended statute of repose would appear to apply to the instant appeal.

The Government disagrees. It contends that the North Carolina General Assembly is without authority to revive the plaintiffs' claims after the repose period has passed. Under North Carolina law, a statute may be applied retroactively "only insofar as it does not impinge upon a right which is otherwise secured, established, and immune from further legal metamorphosis." Gardner v. Gardner, 300 N.C. 715, 719, 268 S.E.2d 468, 471 (1980).

The Government directs us to McCrater v. Stone & Webster Engineering Corp., 248 N.C. 707, 104 S.E.2d 858 (1958), in which the North Carolina Supreme Court considered whether a statute extending the time limitation to file a workmen's compensation claim from one year to two years could be applied retroactively to claims filed more than one year but less than two years from the date of the accident. In other words, if the amendment applied retroactively, the claim would be timely; if not, the claim would be untimely. According to the North Carolina Supreme Court, the time limit to file a workmen's compensation claim was a condition precedent rather than a procedural statute of limitations. Id. at 708, 104 S.E.2d at 860. The court then held that the statute could not apply retroactively because the limitation period was "a part of the plaintiff's substantive right of recovery, [and] could not be enlarged by subsequent statute." Id. at 709-10, 104 S.E.2d at 860. The reason, the court explained, was that any attempt to revive an expired claim "would ... deprive the defendants of vested rights." Id. at 710, 104 S.E.2d at 860.9

Like the time limitation in McCrater, North Carolina's statute of repose is a substantive limit on a plaintiff's right to file an action. See Boudreau v. Baughman, 322 N.C. 331, 340, 368 S.E.2d 849, 857 (1988) ("Ordinary statutes of limitation are clearly procedural, affecting only the remedy directly and not the right to recover. The statute of repose, on the other hand, acts as a condition precedent to the action itself." (citations omitted)). As a result, the repose limitation "is an inseparable part of the plaintiff's substantive right of action." McCrater, 248 N.C. at 710, 104 S.E.2d at 861. And like the limitations period in McCrater, the General Assembly may not enlarge the plaintiffs' claim by statute because to do so would be to divest the Government of a vested right.

The plaintiffs argue that McCrater is inapposite because here it was unclear whether the original statute of repose's reference to "personal injury" encompassed claims for diseases. According to the plaintiffs, Session Law 2014-44 merely clarified the scope of the statute of repose. Whether the statute clarified or altered the statute of repose is relevant because under North Carolina law, clarifying amendments apply retroactively, whereas altering amendments do not. See Ray v. N.C. Dep't of Transp., 366 N.C. 1, 9, 727 S.E.2d 675, 681 (2012). The Government does not have a vested right in the interpretation of the statute of repose, the plaintiffs contend, because there is no final judgment. And to hold that the Government has a vested right would be inconsistent with the rule that a clarifying amendment "does not change the substance of the law but instead gives further insight into the way in which the legislature intended the law to apply from its original enactment." Id.10

At the outset, we disagree that the original statute of repose was ambiguous with respect to a latent-disease exception. See supra at 1380. However, we hesitate to dismiss out of hand the plaintiffs' argument that Session Law 2014-44 clarifies, rather than substantively amends, the statute of repose. Session Law 2014-17 is titled "An Act Clarifying that Certain Civil Actions Relating to Groundwater Contamination Are Not Subject to the Ten-Year Statute of Repose Set Forth in G.S. 1-52," and the title of a law provides some evidence of legislative intent. Cf. Smith Chapel Baptist Church v. City of Durham, 350 N.C. 805, 812, 517 S.E.2d 874, 879 (1999) (explaining that even when the text of a statute is plain, "the title of an act should be considered in ascertaining the intent of the legislature").

Moreover, in § 1 of the session law, the General Assembly found that prior to the Supreme Court's decision in Waldburger, "there was ambiguity and uncertainty regarding the effect of federal law on the North Carolina statute of repose in certain environmental cases." N.C. Sess. L. 2014-44, § 1.11 The legislature also found that "it was the intent of the General Assembly to maximize under federal law the amount of time a claimant had to bring a claim predicated on exposure to a contaminant regulated by federal or State law." Id. Furthermore, the General Assembly found the Supreme Court's decision in Waldburger to be "inconsistent with the General Assembly's intentions and the General Assembly's understanding of federal law" and that "it never intended the statute of repose in G.S. 1-52(16) to apply to claims for latent disease caused or contributed to by groundwater contamination, or to claims for any latent harm caused or contributed to by groundwater contamination." Id. Finally, there is the fact that the General Assembly expressly made the statute retroactive. Although inclusion of an effective date, standing alone, may not prove that an amendment is intended to be clarifying or altering, see Ray, 366 N.C. at 9-10, 727 S.E.2d at 682, the fact that the General Assembly expressly made Session Law 2014-44 retroactive lends further support to the conclusion that the amendment is clarifying and that it applies to the plaintiffs' claims.12

"To determine whether the amendment clarifies the prior law or alters it requires a careful comparison of the original and amended statutes." Ferrell v. Dep't of Transp., 334 N.C. 650, 659, 435 S.E.2d 309, 315 (1993). "If the statute initially `fails expressly to address a particular point' but addresses it after the amendment, `the amendment is more likely to be clarifying than altering.'" Ray, 366 N.C. at 10, 727 S.E.2d at 682 (quoting Ferrell, 334 N.C. at 659, 435 S.E.2d at 315). However, "it is logical to conclude that an amendment to an unambiguous statute indicates the intent to change the law." Childers v. Parker's, Inc., 274 N.C. 256, 260, 162 S.E.2d 481, 484 (1968).

Comparing the two statutes, it is clear that the amended statute of repose contains a brand new exception for groundwater claims. This is not a case where the General Assembly merely failed to address a particular point — whether groundwater contamination claims fall under the statute of repose — only to address it later. In Ferrell, the North Carolina Supreme Court held that a statute setting out the manner of determining the price at which the Department of Transportation would sell a parcel of property was clarifying because the original statute directing the Department to sell parcels provided no express guidance as to selling price. Ferrell, 334 N.C. at 659, 435 S.E.2d at 315. In other words, the clarifying statute filled a hole left by the original statute. Here, by contrast, the General Assembly created a substantively distinct exception from whole cloth. That the legislature saw itself as clarifying the scope of the statute of repose is not irrelevant. But just because the General Assembly said it was clarifying the scope of the statute of repose does not make it so. "It is this Court's job to determine whether an amendment is clarifying or altering." Ray, 366 N.C. at 9, 727 S.E.2d at 681. In this case, the original statute of repose was unambiguous, and it gave no indication that an exception existed for latent diseases. Thus, it is reasonable to conclude the subsequent amendment was substantive. See Childers, 274 N.C. at 260, 162 S.E.2d at 484. Session Law 2014-44 did not adopt the plaintiffs' proposed distinction between latent diseases and other types of claims; instead, it created one for groundwater contamination claims generally, and there is no question that this exception is new.

Session Laws 2014-17 and 2014-44 substantively amended the statute of repose to create an exception for groundwater contamination and, as a result, can only apply prospectively, lest they divest the Government of a vested right. See McCrater, 248 N.C. at 709-10, 104 S.E.2d at 860.

* * *

We therefore have the answer to both questions presented in this interlocutory appeal. First, CERCLA, 42 U.S.C. § 9658, does not preempt statutes of repose. See generally CTS Corp. v. Waldburger, ___ U.S. ___, 134 S.Ct. 2175, 189 L.Ed.2d 62 (2014). Second, North Carolina's statute of repose, N.C. Gen.Stat. § 1-52(16) (2010), applies to the plaintiffs' claims, and it does not contain an exception for latent diseases.13

This case is REMANDED for further proceedings consistent with this opinion.

SO ORDERED.