Orange County Groundwater Replenishment System, Phase I, Huntington Beach, and Fountain Valley, CA
Orange County Groundwater Replenishment System, Phase I, Huntington Beach, and Fountain Valley, CA


Orange County Sanitation Districts

Start Date

February 2004

Project Cost


Project Description

DYA performed the geotechnical investigation for several advanced water treatment facilities.  The facilities and pipelines were proposed at varying depths below ground surface.  The pipeline diameter varied between 20 and 42 inches with a total length of approximately 2.5 miles, with several reaches located below the groundwater level.  The subsurface conditions included shallow groundwater levels, compressible clays, liquefiable sands and silts, and dense end bearing sand layers at depths.  DYP provided recommendations for ground improvement to mitigate liquefaction potential.  Foundation recommendations included spread and mat foundations on improved ground, pile foundations, and minor structures supported on shallow foundations without ground improvement.  We also provided recommendations for construction and permanent slope stability, temporary shoring, construction dewatering, lateral earth pressures for temporary and permanent structures, and monitoring of adjacent facilities because of construction activities.  AWARDS: 2009 Project of the Year from ASCE (Opal Award–Outstanding Civil Engineering Achievement); ACEC Orange County (Award of Excellence) and ACEC California (Engineering Excellence Golden State Award).

Our Services


  • Site and route evaluations
  • Geologic hazards
  • Seismic design
  • Site characterization
  • Subsurface drainage
  • Grading
  • Ground improvement
  • Slope stability
  • Foundations
  • Dynamic analyses
  • Pavements
  • Instrumentation


  • Material sources
  • Construction observation and testing
  • Verification of anticipated conditions
  • Evaluation of changed conditions
  • Foundation installation
  • Instrumentation
  • Claims evaluation


  • Site characterization
  • Remediation
  • Solid and liquid waste disposal
  • Landfill
  • Aerially Deposited Lead (ADL) Studies
  • Phase I Initial Site Assessments (ISA)
  • Phase II Hazardous Waste Studies
  • Sustainability


  • Forensic investigation
  • Litigation support

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