Complex sentence: In 2007, the Ninth Circuit Court of Appeals had ruled favorably for the tribes, it held that the proposed use of treated sewage water would impose a substantial burden on the exercise of religion for the native nations.
Split into simpler sentences: In 2007, the Ninth Circuit Court of Appeals had ruled favorably for the tribes. It held that the proposed use of treated sewage water would impose a "substantial burden" on the exercise of religion for the native nations.