In 2016, a SeHAWK® pilot bioreactor was installed and operated at an Eastern Power Utility. The pilot system explored treatment of selenium, mercury, and other constituents in high TDS water. The pilot successfully removed selenium below ELG limits for the duration of the study with influent TDS concentrations reaching a maximum level of 38,000 parts per million. The pilot was operated with limited pretreatment and at a lower EBCT than a full-scale system which further demonstrates the capability of biological treatment and opens the door for the possibility of reduced capital expenditure in full-scale designs.