Tertiary Wetlands and Reuse Facilities
for the Red Mesa Unified School District

The new lift station at Red Mesa replaced this temporary gas-powered pump.

The Red Mesa Unified School District is located on the Navajo Reservation near the arid Four Corners area of Northern Arizona. In cooperation with the State of Arizona School Facilities Board, PBS&J planned, designed, and assisted with the construction of two wetlands treatment facilities to accommodate wastewater flows projected from the growing populations of the Red Mesa and the Round Rock schools. Key challenges on these projects included the remote location of the facilities, climatic extremes related to temperature, rainfall, and winds carrying sand, highly variable seasonal and diurnal flow rates, and the fact that existing operations personnel at the schools had little formal training in the principles of wastewater treatment. In order to meet these challenges, PBS&J designed a very stable and low maintenance facility consisting of facultative lagoons and tertiary wetlands.

The design philosophy focused on minimizing impacts to the environment, providing recycled water to recharge the groundwater supply, and accommodating stormwater flows. Additionally, all processes and equipment were designed so that school maintenance crews could be readily trained to operate the facility. While the facilities were designed to be economically sensitive to the limited funding available, all state and federal discharge regulations were consistently met for a wide range of operating conditions. The facilities provide a unique educational opportunity for students and the public to learn about the benefits of tertiary wetlands treatment and the role of water recycling in the arid southwest.