Section 267.203 - What special requirements must I meet for incompatible wastes?(a) You may not place incompatible wastes, or incompatible wastes and materials, in the same tank system, unless you comply with § 267.17(b) .(b) You may not place hazardous waste in a tank system that has not been decontaminated and that previously held an incompatible waste or material, unless you comply with § 267.17(b) .