The WPWMA is a regional agency established in 1978 through a joint exercise of powers agreement between Placer County and the cities of Lincoln, Rocklin and Roseville to own, operate and maintain a sanitary landfill and all related improvements.

The WPWMA’s critical facility elements include the Western Regional Sanitary Landfill, Materials Recovery Facility (recycling, composting, household hazardous waste, construction and demolition) and public drop-off.