CO-COMPOSTING BIOSOLIDS AND DAIRY MANURE IN THE CHINO DAIRY AREA: A SOUTHERN CALIFORNIA EXPERIENCE

The Inland Empire Utilities Agency (IEUA) serves an area of 242 square miles with approximately 600,000 people. The Agency is located approximately 35 miles east of Los Angeles and also contains one of the largest concentrations of dairy animals (360,000) in the United States. Biosolids produced by the 600,000 people average about 175 tons per day at 18 percent solids. The 360,000 cows produce approximately 1,000,000 tons per year of manure. The manure is detrimental to water quality because of salinity and nitrates that leach into the groundwater supply.The IEUA Co-Composting facility, located among dairies in the City of Chino, processes 150 wet tons per day (wtpd) of biosolids and approximately 200,000 tons per year of manure. All products are required to be exported from the local groundwater basin. Each ton of manure contains about 154 pounds of salt so the project prevents approximately 15,000 tons of salt from entering the groundwater basin each year. The project economically produces Class A Exceptional Quality (EQ) biosolids through windrow composting with manure. Finished product is marketed to agriculture and horticultural outlets. One hundred percent dairy manure is windrow composted on half of the project. The manure-only compost has recently been certified as organic fertilizer.This paper will cover the challenges of the operations, which include seasonal marketing, low cost transportation, corral cleaning schedules, and control of nuisances. The rural location of the facility has masked nuisance complaints, but nuisance control is becoming a greater focus as urban encroachment surrounds the project. The paper will also cover potential long-term operational changes which may include process changes and/or relocation of the facility.