On October 24, 2016, in Gibson v. Clean Harbors Environmental Services, Inc., the US Court of Appeals for the Eighth Circuit held that in a class action, the 30-day removal period 28 U.S.C. § 1446(b)(3) sets out does not begin to run until the defendant receives a paper from which it can unambiguously ascertain that the class satisfies the requirements of the Class Action Fairness Act of 2005 (CAFA) ( (8th Cir. Oct. 24, 2016)).

In January 2013, plaintiffs filed a class action complaint alleging state tort claims related to the release of chemicals from a hazardous waste storage and treatment facility. Plaintiffs filed an amended complaint in February 2013, naming Clean Harbors Environmental Services, Inc. ("Clean Harbors") as the proper defendant. Plaintiffs' complaint also stated that federal courts had neither diversity nor CAFA jurisdiction because, although the number of class members likely exceeded 400, the amount in controversy requirement was not met.

The case continued in state court. On March 11, 2016, Clean Harbors received a letter from plaintiffs' counsel proposing a settlement of $6,500,000 based on an estimate that the geographic area that the chemical release affected would contain approximately 6,000 class members. On April 21, 2016, Clean Harbor received an expert report from plaintiffs' counsel which described the scientific method used to estimate the geographic area the chemical release affected.

On May 9, 2016, Clean Harbors removed the case to the US District Court for the Western District of Arkansas. Clean Harbors cited CAFA, which provides for federal jurisdiction if, among other requirements, the class exceeds 100 members and the total amount in controversy exceeds $5,000,000. Plaintiffs' counsel moved to remand, stating that Clean Harbors's notice of removal was untimely under 28 U.S.C. § 1446(b)(3), which requires a party to file notice within 30 days of receiving "an amended pleading, motion, order, or other paper from which it may first be ascertained that the case is one which is or has become removable."

The district court agreed with plaintiffs' counsel and remanded the case. The court concluded that removal was untimely because Clean Harbors waited more than 30 days after receiving the March 11 settlement letter, which the court believed provided enough information for Clean Harbors to determine the case was removable under CAFA. Clean Harbors appealed, arguing that the 30-day removal period under CAFA did not begin to run until after it received the April 21 expert report.

The Eighth Circuit agreed with Clean Harbors, reversing the district court's judgment and remanding the case to the district court. The court held that:

Because Clean Harbors filed the notice of removal within 30 days of the April 21 expert report, the motion was timely.