Standard Laying Conditions
ANSI/AWWA C150/A21.50
ANSI/AWWA C151/A21.51
1.) “Flat-bottom” is defined as undisturbed earth.
2.) “Loose soil” or “select material” is defined as native soil excavated from the trench, free of rocks, foreign material and frozen earth.
3.) Granular materials are defined per the AASHTO Soil Classification System (ASTM D3282) or the Unified Soil Classification System (ASTM D2487), with the exception that gravel bedding/backfill adjacent to the pipe is limited to 2" maximum particle size per ANSI/AWWA C600.