Soil aquifer treatment is a practical solution for small wastewater treatment plants where effluent characteristics or other factors rule out discharge to a stream.The Montalvo Municipal Improvement District, on the coast of California between Santa Barbara and Los Angeles, serves a residential and agricultural area with a 1,500 population. Its sequencing batch reactor treatment plant produces advanced secondary effluent at 360,000 gpd.The district uses soil aquifer treatment for its effluent, but found the process limited because alkaline soil causes a buildup of bicarbonate and carbonates beneath its percolation ponds that limited downward water movement.The district worked with Earth Renaissance Technologies
