To amend the Reclamation Wastewater and Groundwater Study and Facilities Act to authorize the Secretary of the Interior to participate in the design, planning, and construction of the Groundwater Replenishment System Expansion to reclaim and reuse municipal wastewater in the Orange County, California region, and for other purposes.

Amends the Reclamation Wastewater and Groundwater Study and Facilities Act to provide for a federal share of a water reclamation, reuse, and treatment project in the Orange County, California region of not to exceed the lesser of 25% of total costs or $26 million (indexed to January 2010 prices). Prohibits the Secretary of the Interior from providing funds for project operations and maintenance.