American Water Works Company, Inc.

ITEM 1. LEGAL PROCEEDINGS

The following information updates and amends the information provided in the Company’s Form 10-K in Item 3—Legal Proceedings. Capitalized terms used but not otherwise defined herein have the meanings set forth in the Company’s Form 10-K and Form 10-Q. In accordance with the SEC’s disclosure rules, the Company has elected to disclose environmental proceedings involving the Company and a governmental authority if the amount of potential monetary sanctions, exclusive of interest and costs, that the Company reasonably believes will result from such proceeding is $1 million or more.

Alternative Water Supply in Lieu of Carmel River Diversions

Monterey Peninsula Water Supply Project

Approvals for Use of Outfall for Water Supply Project Brine Discharge (formerly Regional Water Quality Control Board Approval of NPDES Permit Amendment)

On March 30, 2026, Monterey One Water, owner of the outfall through which the Water Supply Project proposes to discharge brine, approved the submission of an application to the Coastal Commission for a coastal development permit to construct modifications to the outfall to accommodate the brine.

Dunbar, West Virginia Class Action Litigation Settlement

The deadline for claims submissions in this matter was August 25, 2025, and on October 10, 2025, WVAWC made its payments for attorney fees, costs and other expenses under the court’s order granting final approval of the class settlement.

Mountaineer Gas Company Main Break

On November 14, 2025, the Ruffin and Toliver plaintiffs jointly filed for class certification, and a hearing on that motion was held on April 17, 2026. The court also ordered mediation, which took place in March 2026 and was unsuccessful. There is currently no trial date set for these class action lawsuits.

As of March 31, 2026, the Company has received settlement payments from defendants 3M Company. DuPont de Nemours, Inc. and Tyco Fire Products LP totaling $185 million, net of legal fees and administrative costs. The Company is seeking regulatory approval from the respective PUCs to apply the net proceeds of the settlement payments for the benefit of customers, where permissible. As of March 31, 2026, regulatory approvals for such treatment have been obtained with respect to all of the Company’s utility subsidiaries that are parties to the MDL for which such treatment is sought, except three, two of which have been denied, and one of which remains pending. When and as received, funds received by the Company are being held in a law firm escrow account prior to distribution to the Company’s utility subsidiaries that are parties to the MDL after approval or denial is received from the applicable PUCs. As of March 31, 2026, approximately $79 million of the escrowed funds were transferred from the law firm escrow account for distribution to utility subsidiaries that have received approval. The Company anticipates that, during the remainder of 2026, it may receive one or more additional settlement payments from the defendants in the MDL.