CITIES & COUNTIES

The project site is located at the Victor Valley Wastewater Reclamation Authority (VVWRA) Treatment Facility in Victorville, California, where several percolation ponds are periodically used to impound water. These ponds were constructed by forming compacted earth levees around their perimeters.

Group Delta, an NV5 Company, observed during water impoundment, a section of the levee at Pond #9, approximately 100 feet in length and situated five or more feet below the top, exhibits heavy seepage emerging from the slope face. Additionally, less severe seepage has been noted along the levee of Pond #10 to the south.

In response, our team conducted a geotechnical study to provide consultation and recommendations for the contractor’s selected remediation approach, which involved excavation, recompaction, and the construction of a slurry seepage cut-off wall to mitigate seepage through the affected levee zone.

The scope of work included attending a site visit and coordinating with M&E and SSC, reviewing available maps and aerial imagery, analyzing existing geotechnical reports, boring logs, and laboratory test data, plotting soil profiles and cross-sections, and developing geotechnical recommendations to support construction activities.

Value Added

• Focused Seepage Mitigation Strategy: Our team provided geotechnical consultation for the contractor’s selected remediation approach, including excavation, recompaction, and construction of a slurry cut-off wall to address localized seepage at Pond #9.
• Data-Driven Design Support: Our team reviewed historical geotechnical data, boring logs, lab results, and aerial imagery to develop accurate soil profiles and inform targeted recommendations for levee repair.
• Collaborative and Responsive Service: Our team participated in site visits and coordination meetings with project stakeholders to ensure practical, site-specific solutions aligned with operational and environmental needs.