Sampling non-porous surfaces.

(a) Sample large, nearly flat, non-porous surfaces by dividing the surface into roughly square portions approximately 2 meters on each side. Follow the procedures in § 761.302(a) with the exception of the sampling grid size. (b) It is not necessary to sample small or irregularly shaped surfaces. [63 FR 35464, June 29, 1998, as amended at 88 FR 59695. Aug. 29, 2023]