SD24 - Underground Utility Line Separation


Executive Summary:
The State Corporation Commission ("Commission") submits this report to the General Assembly in response to Senate Joint Resolution No. 480 ("SJR480" or "resolution"). The resolution arose out of the concerns of the General Assembly and a July 7, 1998 explosion and fire at 25905 Rickmansworth Lane in the South Riding Subdivision in Loudoun County, Virginia. This accident resulted in the death of one person, severe burns to another, and slight injuries to two others. During the investigation of the accident, a 7/16-inch diameter hole was found in the gas service line owned and operated by the Washington Gas Light Company serving the house in close proximity to the faulted (or failed) electric service lines owned and operated by the Northern Virginia Electric Cooperative.

The General Assembly noted in SJR480 that "... [e]very year, thousands of miles of new utility lines are placed underground in the Commonwealth, and proper separation upon installation is essential to the safe operation and maintenance of these underground utility lines." Following the July 7, 1998 accident, the General Assembly acted upon its concern relative to the proper separation of underground utility lines and, in SJR480, requested the Commission to "... determine whether regulations should be developed concerning electrical and gas utility facility separation."

The resolution also requested that the Commission study and review at least the following: existing laws and regulations; the findings of the National Transportation Safety Board ("NTSB") investigation of this accident; the results of a Voluntary Pilot Program in Loudoun County; and the actions of the Utility Industry Coalition of Virginia. The local, state, and national codes, standards, laws, and regulations were reviewed and no specific requirement for separation distances for underground gas and electric utilities were found. Several regulations exist for the separation of gas transmission lines and mains from other underground structures, and certain industry standards speak to the separation of underground electric facilities from other underground structures, but none specifically address separation between electric and gas underground utility lines.

Section 56-257 of the Code of Virginia authorizes the Commission to establish minimum separation distances on public rights-of-way for all pipes and conduits; however, this code section has certain limitations that need to be addressed. Specifically, this section does not apply to direct-buried cable, facilities outside public rights-of-way, and underground utilities owned and operated by local governments or service authorities. In addition, this section is in conflict with certain regulations promulgated by the Commonwealth's Department of Health.

As stated earlier, the resolution asked the Commission to consider the NTSB findings concerning the accident in the South Riding Subdivision in Loudoun County. The NTSB has not issued any findings as of the date of this report. However, we have included certain information from its laboratory analyses and factual data in Part II of this report.

The results of the Voluntary Pilot Program on utility placement conducted in Loudoun County are discussed in this report. This program involved installations of new underground utility lines in a common trench.

The Utility Industry Coalition of Virginia has submitted a set of standards that include a minimum 12-inch radial separation for underground gas and electric facilities at the time of installation. However, these standards are voluntary, and not all electric and gas utility companies have agreed to follow the standards. Further, certain parts of the standards are vague, and do not encompass all underground utility lines.

After a careful review and analysis, the Commission is of the opinion that proper separation is essential to the safe operation and maintenance of all underground utility lines. Damage to these lines, regardless of who owns or operates them, or where they are located, poses a threat to the health, safety, and welfare of the people of the Commonwealth and the environment. Regulations should be developed for the proper separation of all underground utility facilities, including gas and electric, in both public and private rights-of-way. The General Assembly can accomplish this by either promulgating a law delineating separation distances, or by authorizing the Commission to develop separation standards for all underground utility lines.