Electron Hydro and its chief operating officer pleaded guilty to gross misdemeanor violation in connection with pollution in the Puyallup River and could face up to $1 million in restitution and fines, the Washington State Attorney General Bob Ferguson announced Monday.

Electron Hydro, an electric utility company, and its COO, Thom Fischer, pleaded guilty to operating an unlawful hydraulic project, avoiding a trial for 30 gross misdemeanor charges that was scheduled to begin this week in Pierce County Superior Court.