18. Suitable Material: In the July 21, 1999, Federal Register notice, we did not propose any changes to this general condition, but one commenter requested further definitions of suitable material and debris that can be used.
We do not agree that it is necessary to further define what constitutes "suitable material" for the purposes of this general condition. It is impractical to provide a comprehensive list of unsuitable materials. If there are questions concerning the suitability of a particular material, the permittee should contact the appropriate Corps district office and ask if that material is considered suitable for the purposes of General Condition 18. This general condition is adopted without change.