(1) Each gas pipeline company must investigate any odor, leak, explosion, or fire, which may involve its gas pipelines, promptly after receiving notification. Where the investigation reveals a leak, the gas pipeline company must grade the leak in accordance with WAC 480-93-186, and take appropriate action. The gas pipeline company must retain the leak investigation record for the life of the pipeline.

(2) In the event of an explosion, fire, death, or injury, the gas pipeline company must not remove any suspected gas facility until the commission or the lead investigative authority has designated the release of the gas facility. Once the situation is made safe, the gas pipeline company must keep the facility intact until directed by the lead investigative authority.

(3) When leak indications are found to originate from a foreign source (for example, a gasoline tank, a sewer, a marsh or customer-owned piping), and the situation is ongoing and potentially hazardous, the gas pipeline company must:

(a) Take appropriate action regarding its own facilities to protect life and property; and

(b) Report the leak promptly to the source facility owner or operator and, where appropriate, to the police department, fire department, or other appropriate governmental agency. If the property owner or an adult person occupying the premises is not available, the gas pipeline company must, within twenty-four hours of the leak investigation, send by first-class mail, addressed to the person occupying the premises, a letter explaining the results of the investigation. The gas pipeline company must keep a record of each letter sent for five years.