Reducing Risk Caused by Existing Utilities during Construction of New Pipelines

In today's urban environment, rights of way are becoming crowded with utilities. Existing utilities in any rights of way have the potential to affect construction. With a deliberate, thoughtful approach to establishing the location of existing utilities, understanding the risks associated with each existing utility, and developing a risk mitigation strategy for each utility during construction, costly impacts can be minimized. This paper presents information on the potential availability of utility information and potential inaccuracy of the associated information. With the understanding by the engineer that survey base maps may show locations of utilities inaccurately, project risks can be identified by understanding potential failure modes for utilities. With risks identified, risk mitigation strategies can be developed. This paper also provides examples of how utility mitigation was implemented on King County, Washington's North Beach Combined Sewer Overflow Reduction project.