Water Projects

Otay Water Treatment Plant Expansion and Clearwell Reservoirs

San Diego, California
City of San Diego, Public Utilities
Separation Processes, Inc. (Process Design)
F.H. Paschen/SN Nielsen
ASCE, San Diego Section - Award of Excellence

The City of San Diego, Public Utilities selected Butier Engineering, Inc. to provide construction management, field engineering, administration, and inspection services for the expansion and upgrade of the Otay Water Treatment Plant. The Otay Plant is a critical component of one of the nation’s largest systems for storing, treating, and delivering water to residents and businesses. The City performed the necessary upgrades to meet increasingly stringent water quality standards. To improve water quality, a membrane filtration system was proposed to minimize the formation of disinfection byproducts (DBP) and reduce the overall dependency on chlorine for disinfection. The scope of work consisted of the following:

  • Construction of two 178-foot diameter, 6.5 million-gallon prestressed concrete treated water storage reservoirs (clearwells)
  • Installation of variable frequency drives for two of the raw water pump station’s pumps
  • Construction and installation of piping (48″ overflow and 18″ storm drain piping) and facilities for the membrane filtration system
  • Modifications to existing filters and construction of a third sedimentation basin
  • Installation of an emergency chlorine gas vapor scrubber system for the chlorine building
  • Installation of a UV disinfection system and chlorine contactor
  • Tie-ins to the CWA SD-7 raw water line and the lake water influent line