The Hayden Area Regional Sewer Board has launched a $14.5 million phase of upgrades at its wastewater treatment plant on the Rathdrum Prairie to help it comply with new pollution standards under its federal discharge permit, says Ken Windram, the board’s system administrator.

The project is the first of two planned phases that aim to remove phosphorus and nitrogen from treated wastewater that’s discharged into the Spokane River, Windram says. Phosphorus and nitrogen can contribute to algae blooms in bodies of water and deprive native aquatic life of oxygen.

The project will include constructing new “headworks,” or initial-stage treatment equipment, with updated screening and grit removal equipment, and applying flow-equalization measures to help the plant manage higher usage periods in the mornings and evenings, he says. One component of the project will be a new 800,000-gallon tank that will be part of an enhanced biological nutrient removal system using microbial organisms to remove a higher degree of phosphorus and nitrogen from wastewater.

“The tank will grow bugs to do 90 percent of the work,” Windram says of the microbe system.

TML Construction Inc., of Hayden, is the contractor on the project, and the Spokane office of Boise-based J-U-B Engineers Inc. designed it.

Windram says the project is scheduled to be completed by the fall of 2015.

The first phase will be tested for a year, and then the Hayden Area Regional Sewer Board will embark on the next phase to bring the plant to a higher level of nutrient removal as stricter federal standards are phased in during the next 10 years.

The upgrades also will increase the treatment capacity at the plant, Windram says.

The plant currently treats about 1.2 million gallons of sewage a day. When the second phase is complete, its anticipated capacity will be 2.4 million gallons daily, he says.

The Hayden plant, which is located at 10789 N. Atlas Road, near the Coeur d’Alene Airport, serves about 8,000 homes and businesses. It currently pipes treated wastewater five miles to the Spokane River during normal river flows. 

During summer low flows, the facility applies treated wastewater to land near the plant where a poplar plantation and livestock crops absorb nutrients, protecting the Spokane Valley-Rathdrum Prairie Aquifer from pollutants, Windram says.

The project is being funded through the Hayden Area Regional Sewer Board, the city of Hayden, the Hayden Lake Recreational Water and Sewer District, and Kootenai County via a combination of state and local funds and sewer-service fees.