Anderson Piped Sewer System, Community Wastewater Lagoon, and Regional Septage Facility
This project, which was sponsored by the Alaska Department of Environmental Conservation Village Safe Water Program, is providing (1) a new regional septage facility, operated by the City of Anderson, to serve the Denali Borough and the city of Nenana and (2) a wastewater collection system and community lagoon for the city of Anderson. RESPEC updated a previous feasibility study, identified and evaluated site alternatives for the septage facility and wastewater lagoon, and designed the piped sewer and lagoon facilities.
Construction of the regional septage disposal facility was completed in 2007. The facility has two primary cells for receiving and dewatering the sludge in preparation for freeze/thaw conditioning. A facultative cell treats the liquid from the primary cells before discharging to a percolation cell, and the conditioned sludge then transfers to an on-site monofill.
The community wastewater lagoon in Anderson will be a two-cell facultative lagoon located in the floodplain of the Nenana River that discharges continuously into a percolation cell. The selected site balanced the community’s desire to maximize the distance from adjacent houses with the need to minimize the expense of construction on slightly less-desirable ground.
The piped sewer system, which will serve all of Anderson, will replace septic-tank and leach-field systems that threaten the water quality of shallow, private wells nearby. The collection system will include 23,400 linear feet of 8-inch ductile iron pipe (DIP) gravity sewer main, 86 manholes, and 4-inch service connections at each house. At the lower end of the collection system, 1,900 linear feet of 6-inch, high-density polyethylene (HDPE) force main will connect the sewer lines to the lagoon.