40 CFR § 265.257 - Special requirements for incompatible wastes.
§ 265.257 Special requirements for incompatible wastes.
(a) Incompatible wastes, or incompatible wastes and materials, (see appendix V for examples) must not be placed in the same pile, unless § 265.17(b) is complied with.
(b) A pile of hazardous waste that is incompatible with any waste or other material stored nearby in other containers, piles, open tanks, or surface impoundments must be separated from the other materials, or protected from them by means of a dike, berm, wall, or other device.
[Comment: The purpose of this is to prevent fires, explosions, gaseous emissions, leaching, or other discharge of hazardous waste or hazardous waste constituents which could result from the contact or mixing of incompatible wastes or materials.]
(c) Hazardous waste must not be piled on the same area where incompatible wastes or materials were previously piled, unless that area has been decontaminated sufficiently to ensure compliance with § 265.17(b).