Boise, Idaho, is proving there’s more than one way to skin the phosphorus cat.Facing ever-increasing phosphorus removal requirements, the city could have incorporated additional phosphorus removal equipment at its two wastewater treatment plants. Instead, Boise designed and built a unique facility down-river that removes phosphorus from agricultural runoff.Called the “Dixie Drain,” the facility employs a simple process train of chemical addition, flocculation and sedimentation. It removes phosphorus at a rate that more than offsets what could have been achieved with additional point source treatment upstream.“It’s working well,” Shawn Wilson, project manager, says of Dixie Drain, which is in its second
