DESCRIPTION: The City of Jefferson completed a series of improvements to their existing wastewater treatment plant (WWTP), which was built on a bench of fill that extends ±5 to 8 feet above the adjacent terrain. The main project elements include construction of a new sequencing batch reactor (SBR), a laboratory and office building, a pump station and new headworks.
SERVICE: Foundation Engineering completed a geotechnical investigation for the project. The site improvements required fill to match the grade of the existing facility. Challenging site conditions included a layer of very soft silt. Key geotechnical issues included options for mitigating potentially recessive settlements due to the weight of new site fill and structures. Our scope of work included exploratory borings, laboratory testing, engineering analyses and development of recommendations for site preparation. Foundation Engineering also provided construction observations and consultation during site grading and foundation preparation.