Inland Empire Regional Composting Facility



The Inland Empire Regional Composting Facility (IERCF) was constructed in 2007 under a Joint Powers Authority agreement between IEUA and the County Sanitation Districts of LA County (CSDLAC). The IERCF, located in Rancho Cucamonga, is completely enclosed to control odors to meet stringent air quality regulations and is the nation’s largest indoor biosolids composting facility.

The IERCF uses the Aerated Static Pile composting process to recycle approximately 150,000 wet tons/year of dewatered and stabilized biosolids from the Agency and CSDLAC’s wastewater treatment processes as well as wood waste from local communities. It produces over 230,000 cubic yards of high quality compost each year for local landscaping and horticultural use. The composted product, which is marketed as SoilPro® Premium Compost, is sold as a soil conditioner which helps improve water retention, resulting in better plant growth and water savings.

The facility is currently operating at its design capacity, receiving nearly 600 tons per day of biosolids and recycled waste products. The RP-1 Dewatering Facility, listed in the capital projects list in the following section, which will use centrifuges to dry solids to a higher percentage, has the potential of freeing up 50 wet tons per day of additional capacity at the IERCF.