To investigate the feasibility of sand bioreactors treating butterfat supplemented with detergent, three layer reactors and two layer reactors were compared. Both options showed great COD and BOD5 removal. However, the two layer bioreactors became clogged in half the amount of time than compared to the three layer bioreactors. Sulfate-reducing bacteria was recovered from the bottom zones of the columns indicating the presence of anaerobic pockets.