The Elk River Wastewater Treatment Plant (WWTP) processes solids via anaerobic digestion, and then provides further treatment and biosolids storage in facultative sludge lagoons (FSLs). Biosolids are harvested (dredged) from lagoons in the summer months and land-applied on 85 acres
of land owned by the City of Eureka, California. The land base is inadequate to accommodate 100 percent of biosolids production. As a result, a solids inventory has accumulated in the lagoons and effective capacity is compromised. A biosolids dewatering facility design is in progress to
address this issue. After review of available technologies, the FKC® screw press was pilot-tested and a request for a price quote was issued. The FKC process can dewater FSL solids to facilitate transport to more distant agricultural land. The process includes an option to provide lime
pasteurization and generate a more marketable Class A biosolids product. In addition to dewatering and lime pasteurization, a covered slab will be included in the upgrade to provide seasonal product storage and improve product marketing flexibility. To allow rapid project implementation
and relieve storage in the lagoons, a design/build procurement strategy was initially considered. However, the decision to stick with conventional procurement was subsequently made to retain greater control over facility design. To address the immediate solids inventory problem, additional
application sites will be permitted on agricultural land within 10 miles from the WWTP. The current direction for improvements is to implement dewatering only initially, and then upgrade to provide lime feed and heating. Potential markets for a Class A biosolids product include local compost
and topsoil blending, as well as local soil improvement. Savings on future Class A product handling and transportation are expected to help offset increased processing costs.
Proceedings of the Water Environment Federation is an archive of papers published in the proceedings of the annual Water Environment Federation® Technical Exhibition and Conference (WEFTEC® ) and specialty conferences held since the year 2000. These proceedings are not peer reviewed. WEF Members: Sign in (right panel) with your IngentaConnect user name and password to receive complimentary access.