In the first project of its kind in North America, the Tahoe-Truckee Sanitation Agency (TTSA) in California has awarded USFilter a $5.8 million contract for a tertiary biological aerated filtration system to meet strict nitrogen removal requirements on the Truckee River.
The 10 mgd BioStyr® system will be designed to meet inorganic nitrogen limits of less than 3.0 mg/L in winter and less than 2.0 mg/L in summer, while dealing with influent temperatures that can range seasonally from 34 to 50 degrees F.
"The strict inorganic nitrogen limits plus the abrupt and sizeable variations in influent temperature and peak loads, make this a very demanding application for nitrogen removal," said USFilter's Tony Freed, regional product manager for biological systems.
The Biostyr system will be supplied by USFilter's Kruger Products, Cary, N.C. It combines biological treatment with upflow filtration in a single, multi-cell structure. The BioStyr system will consist of eight nitrification cells followed by four denitrification cells for maximum operational flexibility under the fluctuating flow and loading conditions present at TTSA. Its small footprint makes it ideal for plant upgrades and expansions.
Craig Woods, agency manager, said the Biostyr process will facilitate increased capacity and enhanced treatment at the TTSA facility.
"It's a more environmentally friendly process than the system we have been using," he said, "and will enable us to boost capacity from 7.4 to 9.6 mgd."
The agency serves about 35,000 residents along the north and west shores of Lake Tahoe, including Alpine Springs, Squaw Valley and the greater community of Truckee. On weekends, the population can balloon to 100,000 or more.
Design engineering firm for the project is the Redding, Calif. office of CH2M Hill.
