Chad Andrews is a Professional Engineer in the State of Florida holding a B.S. and M.S. in Environmental Engineering with an emphasis in Water Resources from the University of Georgia. Prior to joining Underground Solutions, Chad worked in the water resources industry as a GIS Technician, Research Staff Engineer and a water resources engineer/consultant for several years. Chad has been employed within Aegion’s Infrastructure Solutions division as a Regional Manager for Underground Solutions for 7 years, specializing in pipeline rehabilitation and new pipeline construction technologies. He provides technical assistance to end-users, engineers, and contractors for water, wastewater and electrical conduit pipelines.

Two primary trenchless methods for installing utilities under interstates include jack and bore and horizontal directional drilling. The pros and cons will be discussed for each installation method to better understand their application for different projects with a focus on horizontal directional drilling.  Horizontal Directional Drilling has become a preferred method for crossing waterbodies, existing utilities, county roads, and DOT highways for water, sewer, and conduit all over the United States. Current horizontal directional drilling practices will be discussed, followed by case study review for casing and/or carrier pipe under an ALDOT highway.  Thermoplastic pipe has been installed under DOT highways for more than 15 years and most recently a 630 LF HDD of 12” casing with 8” water main carrier near Attalla, AL crossing Interstate 59. The paper will review material properties of thermally butt-fused pipe materials that lend for DOT crossings while minimizing impact to communities.  The project was completed in 2022 and the bore segment took around 2 weeks to complete.