An environmental lawyer who wrote an amicus brief in San Francisco v. EPA believes a criticized ruling actually means tougher standards.

The U.S. Supreme Court sided with San Francisco on Tuesday in a ruling that narrows the Clean Water Act. The case pitted a city that champions environmental policies against the federal agency tasked with protecting the environment.

The Supreme Court has made it harder for environmental regulators to limit water pollution, ruling for San Francisco in a case about the discharge of raw sewage that sometimes occurs during heavy rains.