Billing Code: 4910-60-P
DEPARTMENT OF TRANSPORTATION
PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION

Pipeline Safety: Closure of Gas Shut-Off Valves Serving Permanently Moored Vessels (PMV) During High-water Conditions

AGENCY: Pipeline and Hazardous Materials Safety Administration (PHMSA), DOT.

ACTION: Notice; issuance of an advisory bulletin.

SUMMARY: The Office of Pipeline Safety (OPS) is issuing this advisory to gas distribution pipeline system operators. Operators should examine the shut-off valves controlling gas service to permanently moored vessels (PMV) and ensure that gas service can be quickly shut down, if necessary, even during high-water conditions. In addition, operators should review their operations and maintenance manual and their emergency response manual to ensure that procedures are in place to successfully shut down the flow of gas to PMVs when necessary, including during high-water conditions.

ADDRESS: This document can be viewed at the OPS home page at: http://ops.dot.gov.

FOR FURTHER INFORMATION CONTACT: Richard Huriaux, (202) 366- 4565, or by e-mail, richard.huriaux@rspa.dot.gov.

SUPPLEMENTARY INFORMATION:

I. Background

On September 27, 2000, the National Transportation Safety Board (NTSB) recommended that the Pipeline and Hazardous Materials Safety Administration "require corrective action as appropriate to ensure that pipeline operators have the means to shut off the flow of natural gas to permanently moored vessels in a timely manner, even during periods of high-water conditions" (Safety Recommendation P-00-14).

This recommendation resulted from NTSB's investigation of a natural gas leak on a permanently moored vessel (PMV), the President Casino on the Admiral (Admiral), on April 4, 1998. The Admiral was struck by barges that detached from a tow during high-water conditions on the Mississippi River in downtown St. Louis, Missouri. The Admiral lost most of its mooring lines, causing the barge to rotate away from the quay, severing the gas service line. The natural gas did not ignite, but an emergency repair crew was unable to shut off the gas supply because the flooded regulator pit made it impossible to reach the shut-off valve. After three hours the crew was able to clamp-off the line and stop the flow of gas.

The local gas distribution company has taken action to ensure that all service line shut-off valves controlling gas flow to PMVs are provided with a means to stop the flow of gas, even during high-water conditions. It will either locate gas service line valves where they will not be affected by flooding or install equipment, such as extra-height operators or valve key guides, that will allow service valves to be readily operated during flood conditions.

There are hundreds of PMVs in U.S. waters. This incident highlights the need to evaluate the accessibility and operability of gas service line valves serving PMVs. Although not all these valves are subject to potential high-water conditions, gas distribution pipeline system operators serving PMVs should ensure that they can promptly shut down the flow of natural gas to PMVs, even during high-water conditions.

The Federal pipeline safety regulations require that "each service line must have a shut-off valve in a readily accessible location . . ." (49 CFR 192.365(b)). This implies that the valve must be operable under all reasonably anticipated conditions. For PMVs, it is reasonable to anticipate that high-water and flooding might occur. Operators should review their operations and maintenance manual and their emergency response manual to ensure that procedures are in place to successfully shut down the gas to PMVs when necessary, including during high-water conditions. (49 CFR 192.605).

II. Advisory Bulletin (ADB-01-01)

To: Owners and Operators of Gas Distribution Systems.

Subject: Closure of Gas Shut-Off Valves Serving Permanently Moored Vessels (PMV) During High-Water Conditions

Purpose: To advise gas distribution pipeline system owners and operators of the need to examine the location and functionality of shut-off valves to make sure they can promptly shut down the flow of gas, even in the event of high-water conditions.

Advisory: Owners and operators of gas distribution pipeline systems should examine the location of gas shut-off valves serving PMVs to ensure that they can be located and used, even during high-water conditions. If not, the valves should be moved to a location above the reasonably anticipated high-water mark or equipped to be readily accessible during high-water events. In addition, operators should review their operations and maintenance manual and their emergency response manual to ensure that procedures are in place to successfully shut down the gas to PMVs, when necessary, including during high-water conditions.

Issued in Washington, D.C. on _____________________.

Stacey L. Gerard

Associate Administrator

for Pipeline Safety