Grizzly Bear Cabins and Campground in Dcnali, Alaska, needed a larger onsite system to handle a major expansion. Across the road, the undersized system for Dcnali River Cabins complex also needed replacement.
Bio-Microbics engineer Reza Shams, Ph.D. helped design engineer Bob Tsigonis, PE., owner of Lifewater Engineering Co. in Fairbanks, to address numerous challenges. Both properties had potable wells and minimal space, ruling out new or replacement drainficlds. Effluent discharging to the Ncnana River had to meet stringent requirements.
'The systems operate May through September, so winter storage was an issue,' says Tsigonis. 'We had to wait until the snow melted and the ground thawed to install them, leaving only a few weeks before the first guests arrived.'
His solution used UxtrcmeSTP sewage treatment plants from Lifcwater Engineering. The units, designed to work on permafrost soils, use bioreactors and BioBarricr flat-plate membrane technology from Bio-Microbics Inc. to produce extremely high-quality effluent for environmentally sensitive areas.
The systems are above ground on compacted gravel pads. The sites arc less than 500 feet from the Ncnana River and next to Denali National Park.
Tsigonts designed the Grizzly Bear system to handle 8,000 gpd and the DRC system to handle 24,000 gpd on completion of the complex.
The Grizzly Bearsystem's major components are three 1,750wgallon dualwcompartment plastic septic tanks with BioSTEr pump vault systems from Bio~Microbics,two 1,000wg.1.1I0n dual-compartment plasw tic septic tanks in series with the BioSTEP system, and an 8,000-galIon ExrrcmeS1l' plant with BioBanier membranes in a 40-foO[-long shipping container.
The Denali River Cabins system included a 500wgallon grease interw ceptor, 1,000wgallon plastic tank with BioSTEP system for the launw dry and employee kitchen, an e.xisting 12,000-galion. two-compartment steel septic tank, and a 2'~,000-galIon ExrremcSTP plant in three sidcbywside 40wfoot-long containers.
Both systems have custom-built Welrbased control systems from Ufewater Engineering.