Development of Kodiak, Alaska’s Successful Composting Program

The City of Kodiak (City) on Kodiak Island is located 400 kilometers (250 miles) southwest of Anchorage at the westernmost edge of the Gulf of Alaska. As such, it is an isolated community, only reachable by boat or by plane. The Island’s main local government consists of two bodies, the City of Kodiak and the Kodiak Island Borough (KIB). In addition, the island houses the largest Coast Guard Base in the United States. The combined population of the City, KIB and the Coast guard base which generate wastewater solids that must be managed is approximately 14,000 persons. The City’s existing 17.8 mega-liter/day (4.7 MGD) capacity secondary wastewater treatment facility (WWTF) currently treats an average flow of 6.8 mega-liters per day (1.8 MGD). Faced with dwindling landfill space and skyrocketing fees at the island’s largest landfill owned and operated by the KIB, the City of Kodiak embarked on a Biosolids Management Study in 2007 to evaluate solids management options to landfilling dewatered wastewater residuals. Incineration, thermal drying, the Cannibal™ process and composting were the four alternatives evaluated. Composting was selected by the City based on costs and the consistency of the technology with the City and KIB’s philosophies, goals and objectives. This paper provides information on the background used for selecting composting to manage the City’s wastewater solids. In addition, planning, permitting, public outreach as well as design features and operating experience are provided.