Commercial grease interceptors are available in sizes from 520 gallons to 3,200 gallons. Sand/oil separators come with two-baffle and three-baffle options. Two-baffle separators are available in sizes from 900 gallons to 3,200 gallons; three-baffle separators and clarifiers are available in three sizes: 1,400, 2,500 and 3,200 gallons.