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Fat, oil and grease in wastewater can be difficult to treat because of their slow decomposition. Traditional pretreatment facilities to remove fat, oil and grease from wastewater are increasingly costly. In our laboratory we have research program on using sand filtration to treat wastewater that contains animal fat. In this study, we evaluated the efficiency of the pretreatment of simulated turkey processing wastewater with sand bioreactors that were dosed three times a day at 132 L/m2/day. Pretreatment facilitates the conversion of COD to BOD5 for subsequent biological treatment. Two types of coarse sand bioreactors were employed: (i) one set with a varying depth of coarse sand, and (ii) the second set was similar with an additional pea gravel cap. The results indicated that the relative removal of COD was improved in the sand bioreactors with a pea gravel cap irrespective of the depth of coarse sand. Pea gravel may act as a sieve to entrap organic matter including fat globules from the wastewater. Multiple dosing at the same loading rate showed slightly improved treatment efficiency of the sand bioreactors.