Water Replenishment District of Southern California
Pico Rivera, CA
- Geotechnical Testing
10% of California’s population is within the Water Replenishment District of Southern California’s service area.
The Leighton Solution.
Included in the 9.6-acre project is a process building, a 30-foot deep equalization basin, chemical storage containment and treatment tanks, three injection well vaults, water tower, SCE transformer, pump station, buried piping, metering and feed pumps, and stormwater infiltration devices, and Operations and Learning Center.
Leighton provided geotechnical design and construction phase testing as part of the design-build team. Unique challenges of the project included liquefaction potential and dewatering for construction of the equalization basin. To mitigate the impact of liquefaction, Leighton designed a geogrid-reinforced soil mat below the buildings and storage/treatment tanks. This mitigation technique is much cheaper than a pile foundation system or other ground improvement methods such as stone columns and compaction grouting.
We developed recommendations for removal of groundwater from the adjacent San Gabriel River for construction of the equalization basin, including a collection system, sump pumps and use of crushed rock for soil stabilization.
During construction, Leighton provided observation and testing services of site grading, building pad preparation, footing excavations, backfill of underground structures and utility trenches, aggregate base and asphalt concrete. Leighton also provided materials testing services that included concrete sampling and QC testing of concrete compressive strength.