In 2003, New Hampshire filed suit in state court against several gasoline suppliers, refiners and chemical manufacturers (MTBE defendants) seeking damages for groundwater contamination allegedly caused by MTBE. The case was removed, and then remanded. The New Hampshire Supreme Court held that the state had parens patriae authority to bring suit against the MTBE defendants on behalf of the people of New Hampshire. The state sought to recover remediation costs for both public water systems and private wells, arguing that it had such authority as public trustee of the state’s water and as parens patriae for its citizens. The defendants challenged the state’s authority to recover damages for testing and treatment of private wells.