Additional Information - Posters # 2006 Washington DC
With an increase in trenchless methods being employed for the installation of natural gas lines in urban areas, unmarked sewer service laterals present a risk of accidental and unknowing crossbores with these distribution lines. While the physical damage to underground facilities is always unwanted, a cross-bored plastic pipe natural gas distribution line in a sewer lateral is vulnerable to sewer cleaning tools that may be used in the event of a backup, with potential explosive consequences. There exists good practices for operators of horizontal boring equipment; however, these assume that the existing underground structures otherwise are marked and/or located. State legislation mandates the marking and locating of underground infrastructure; however, the question of who assumes responsibility for marking and locating sewer service laterals is a contentious one. Sewer system owner/operators generally place the responsibility of locating and marking in the hands of unsuspecting property owners claiming that the laterals are on private property. In reality, property owners lack the expertise and equipment to mark and locate these service laterals. This paper describes the challenges with respect to natural gas cross-bores in unmarked sewer service laterals.