In June 2014, the California Division of Drinking Water adopted the Groundwater Replenishment Recharge Regulations, allowing for spreading of recycled water treated to Title 22 standards supplemented by adequate dilution water. Facing this regulatory change, LADWP wanted to understand the soil aquifer treatment (SAT) process and how it may impact potable reuse in the coming years. Soil columns were demonstrated and operated to mimic a potential full-scale groundwater recharge practice to characterize the effectiveness of SAT by loading the soil columns with local aquifer media, feeding the soil columns with recycled water proposed for the project, and operating the soil columns in a cyclic mode to simulate regional groundwater recharge practices.
In addition to the research report, one-year of extended testing was conducted to allow for further acclimation of the 6-month soil column, verification of the ‘fresh’ source water, and verification of sustainable operation of the soil columns and their removal efficacy. Under the extended testing, NDMA, CECs, TOC, and other water quality parameters were monitored with tertiary effluent as the source water. The extended testing report is posted below, under Project Papers.
Research partner: Los Angeles Department of Water & Power.
Published in 2017.