Matthew Hinkson, P.E., project engineer for San Antonio Water System’s (SAWS) Construction Inspection was the guest speaker at the bi-monthly Gulf Coast Trenchless Association meeting held in April. He is a graduate of UT-Austin’s College of Engineering and is a Texas Registered Professional Engineer.
SAWS is a city-owned utility that provides clean drinking and sanitary sewer services to its residents and businesses. Hinkson discussed the city of San Antonio’s most recently completed project to improve the city’s sanitary sewer system – the Western Watershed Sewer Relief Line (W-04) project.
The $19.8 million project, funded by the Texas Water Development Board, is located in the Ingram Park Mall/SWRI area of San Antonio from just south of Loop 410 to west of the Pipers Meadow Subdivision. The project involved the construction of approximately 14,050 feet of 66-, 60- and 54-inch diameter FRP (fiberglass reinforced plastic) and 18- and 8-inch diameter PVC sanitary sewer mains, with the depth of the interceptor ranging from 10 to 55 feet below ground surface. Several construction methods were used on this project which included: open-cut, TBM tunneling, hand tunneling and conventional boring along the Leon Creek.
The W-04, which replaced more than two miles of large diameter sewer main, also features SAWS’ first vortex manhole at the intersection of two large sewer mains. The vortex unit is about 9 feet in diameter and more than 15 feet tall and sits inside a concrete structure that is 24 feet in diameter and 24 feet tall. The vortex unit guides sewage from both sewers into one pool to help get oxygen into the sewage and decrease odor. It also reduces some of the corrosive properties of the sewage.
Engineering of the W-04 segment was done by Weston Solutions Inc., San Antonio. General contractor was BRH Garver Construction, Houston.
The project work started in July 2007 and was completed in April 2009.
For more detailed information about this project, see Underground Construction’s March issue, pgs. 30-33, “Tunnel Project Helps Meet San Antonio Growth.”
For more information about future GCTA luncheons or the association, contact Ginger Coleman at (713) 839-0808; email@example.com; www.gctaonline.org.