Please clarify the the term "homogeneous area," under the Asbestos Hazard Emergency Response Act (AHERA), which has a regulatory definition of being uniform in color or texture, when applied to pipe lagging that's been discolored or applied differently.

A certain number of bulk samples (based on the size of the area) are required for each homogeneous area as described at 40 CFR part 763.86(a). The accredited inspector must make a judgment on whether pipe lagging is indeed uniform in color and texture, and therefore a homogeneous area. If the suspect material looks darker due to water damage, it is appropriate for the inspector to consider this as part of the same homogeneous area. If the suspect material has been applied differently, however, it probably would not be uniform in color and texture since there would be a noticeable difference in the suspect material's appearance. This non-homogeneous area would require separate bulk samples. (40 CFR part 763.86(a))