Minimizing public exposure to cross-bores in unmarked sewer service laterals

With an increase in horizontal directional drilling being employed for the installation of buried utilities in urban areas, unmarked sewer service laterals present a risk of accidental and unknowing cross-bores with these distribution lines. While the physical damage to underground facilities is always unwanted, a major concern facing utility contractors are catastrophic losses resulting from utility lines that are exempt from locating laws. Even the most professional HDD contractors are being held liable for hitting these unmarked, unknown lines. The insurance industry is rapidly becoming aware of this exposure and is subsequently making it difficult and costly for contractors to secure insurance for trenchless utility projects. 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. System owners/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 discusses the issue of current legislation pertaining to unmarked sewer service laterals and examines ways for minimizing exposure to public risk from cross-bores. Copyright ASCE 2006.