WAC 480-75-640. Depth-of-cover survey

For pipelines constructed after April 1, 1970, each pipeline company must conduct a depth-of-cover survey in its pipeline rights of way every five years to ensure the minimum depth-of-cover as required by subsections (1) and (2) of this section has been maintained for the entire pipeline. In areas subject to erosion and subsoiling, the survey must be conducted every three years. (1) Unless specifically exempted in this section, each pipeline company must bury all pipe so that it is below the level of cultivation. Except as provided in subsection (2) of this section, the pipe must be installed so that the cover between the top of the pipe and the ground level, road bed, river bottom, or sea bottom, as applicable, complies with the following table: Location Cover (inches) For normal excavation Cover (inches) For rock excavation Industrial, commercial, and residential areas 36 30 Crossings of inland bodies of water with a width of at least 100 ft. from high water mark to high water mark 48 18 Drainage ditches at public roads and railroads 36 36 Deepwater port safety zone 48 24 Any other area 30 18 Location Cover (inches) For normal excavation Cover (inches) For rock excavation Industrial, commercial, and residential areas 36 30 Crossings of inland bodies of water with a width of at least 100 ft. from high water mark to high water mark 48 18 Drainage ditches at public roads and railroads 36 36 Deepwater port safety zone 48 24 Any other area 30 18 Note: Rock excavation is any excavation that requires blasting or removal by equivalent means. (2) Cover less than the minimum required by subsection (1) of this section may be used if: (a) It is impracticable for the pipeline company to comply with the minimum cover requirements; and (b) The pipeline company provides additional protection equivalent to the minimum required cover.