We were contacted by a general contractor concerned about groundwater problems while installing a new headworks building at an upcoming WWTP improvements project.  CDS obtained digital copies of the Site Plans, Specifications, and Geotechnical Report to start right away designing a dewatering system.

The jobsite showed challenges of heavy clay on top, silty fine sand in the middle of the excavation and underlain by clay & limestone.  At a site visit the owner reported their well on site exhibiting artesian flows during high groundwater events.  CDS also researched local well logs to confirm site conditions and assumptions. Utilizing this information we worked with the owner, general contractor, and engineer to custom design a dewatering system that fit the project and budget.

CDS’s solution was a dewatering system installed around the perimeter of the excavation to control groundwater and allow installation of boards and lagging Earth retention system.  As noted in the pictures efforts were successful and the excavation was completed without complications.

CDS was tasked with designing a dewatering system for the construction of the “Rack 12” Combined Sewer Overflow (CSO) Basin in the town of Akron, OH.  CDS routinely works on CSO basin projects all over the Midwest.

As cities look for ways to comply with the Consent Degree laws, often the solution is large deep storage basins with upgrades to major sewer piping and interceptor sewers.  At this project CDS was required to lower the groundwater on the order of 25’ for the construction of the CSO basin with approximate 200’ x 400’ excavation.

The picture below shows the jobsite the first day of drilling, with obvious water in the excavation after removing the topsoil.