(1) Each gas pipeline company must have detailed written procedures for the storage, handling, and installation of plastic pipelines. Except for joining procedures, and unless the gas pipeline company has more stringent procedures, the company must store, handle, and install plastic pipe in accordance with the latest applicable manufacturer's recommended practices.

(2) The gas pipeline company must follow the manufacturer's recommendation for maximum cumulative ultraviolet light exposure limit for plastic pipe. If there is no such recommendation, the gas pipeline company must not expose plastic pipe to ultraviolet light for more than two years. Each gas pipeline company must include the applicable ultraviolet exposure time limit in its procedures manual.

(3) Each gas pipeline company must install a weak link on each plastic pipe that is pulled through the ground by mechanical means, to ensure the pipe will not be damaged by excessive tensile forces.

(4) When a gas pipeline company installs plastic pipelines parallel to other underground utilities, it must ensure there is a minimum of twelve inches of separation from the other utilities. Where a minimum twelve inches of separation is not possible, a gas pipeline company must take adequate precautions, such as inserting the plastic pipeline in conduit, to minimize any potential hazards resulting from the close proximity to the other utilities.

(5) When a gas pipeline company installs plastic pipelines perpendicular to other underground utilities, it must ensure there is a minimum of six inches of separation from the other utilities. Where a minimum six inches of separation is not possible, a gas pipeline company must take adequate precautions, such as inserting the plastic pipeline in conduit, to minimize any potential hazards resulting from the close proximity to the other utilities.

(6) Except for approved steel encased plastic pipe, and except where allowed by (b) of this subsection, a gas pipeline company may temporarily install plastic pipe above ground for no longer than thirty days.

(a) During such temporary installations, the gas pipeline company must monitor and protect above ground plastic pipe from potential damage.

(b) A gas pipeline company may install above ground plastic pipe for periods longer than thirty days if it has a written monitoring program and if it notifies the commission by telephone using the emergency notification line (see WAC 480-93-005(8)) prior to exceeding the thirty-day time limit.

(7) Plastic pipe must be bedded in a suitable material as recommended by the pipe manufacturer. Unless otherwise permitted by the manufacturer, plastic pipe must be bedded in an essentially rock-free material.

(8) Plastic pipe may not be squeezed more than one time in the same location.

(9) Plastic pipe must not be squeezed within twelve inches or three pipe diameters, whichever is greater, from any joint or fitting.