Composing a composting solution in The Last Frontier: Development of successful biosolids composting program in Kodiak, Alaska

The City of Kodiak is located 400 km (250 mi) southwest of Anchorage. It sits at the westernmost edge of the Gulf of Alaska. As such, this 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 U.S. The...

From 1997 to 2000, the city built $8 million of WRRF upgrades required because of capacity and solids disposal issues at KIB landfill. In 2007, the city hired CH2M Hill (Englewood, Colo.), a professional engineering company, to conduct a biosolids management feasibility study for alternatives to landfilling of lime-treated biosolids. The study identified and evaluated the three treatment...

In June 2012, the landfill informed the city that in 6 months it would no longer accept wastewater solids for disposal. This deadline did not allow enough time for the full composting facility to be built, and the city entered a partnership with a private company to compost biosolids on space atop the existing landfill as a temporary Class B operation permitted by ADEC. The private company would...

The Kodiak composting facility is designed to process 360 dry tonne/yr (400 dry ton/yr) with an average total solids content of 18%. Each year, the facility buys 1900 m3 (2500 yd3) of wood chips to be used as the bulking agent. The facility is located next to the landfill with the plan to divert waste wood material and other segregated carbon-rich materials from the landfill...

The full-scale facility began operating in December 2015. After facing public scrutiny about the capability of the private company that operated the interim facility, the city took ownership of running the full-scale facility. The design engineer worked closely with city staff to aid in startup and detailed operator training regarding process control, monitoring, and recordkeeping.

The capital cost of the compost facility was $3.45 million in 2015. A new covered storage area was added in 2016 at a cost of $1.1 million. Operating costs were tracked in 2016 and continue to decrease as more operational experience is gained. Operating costs include labor, bulking agent, electricity, fuel, laboratory testing, and maintenance.