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 |
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.
[Statutory Authority: RCW
80.01.040,
80.04.060,
81.88.040. WSR 08-12-045 (Docket PL-070974, General Order R-548), § 480-75-640, filed 5/30/08, effective 6/30/08. Statutory Authority: RCW
80.01.040 and
80.04.160. WSR 02-18-032 (Docket No. TO-000712, General Order No. R-500), § 480-75-640, filed 8/26/02, effective 9/26/02.]