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Miramar Water Treatment Plant Upgrade and Expansion Project

Project Description

Aerial view of Miramar Water Treatment Plant

The City of San Diego Public Utilities Department's Miramar Water Treatment Plant (WTP) began operation in 1962. The treatment plant is the sole provider of drinking water to an estimated 500,000 customers in the northern section of the City. The plant is located in the Scripps Miramar Ranch community on the shore of Miramar Reservoir, which is also a popular recreation site. Currently the plant produces 140 million gallons of drinking water a day (mgd). Water sources for the treatment plant are imported water from northern California and the Colorado River brought into San Diego by the San Diego County Water Authority and local rainfall captured in the reservoir.

The upgrade and expansion project began in summer 1998 with construction starting in May 2001 with the Early Start Improvements Phase I. The project is expected to be completed in early 2013. The Miramar Water Treatment Plant Upgrade and Expansion Project includes a new rapid mix facility, installing new de-aeration basins, disinfection facilities, new chemical facilities, new and refurbished administration facilities, flocculation and sedimentation basins, washwater recovery system and water filters.

Project Begins (Design Phase): Summer 1998

Construction Begins: April 2001

Construction Complete: Early 2013

Project Benefits

  • Water treatment capacity will increase from 140 to 215 million gallons per day.
  • The project increases water delivery reliability to meet current and future water needs.
  • The upgrades will meet or exceed new, stricter federal and state drinking water standards.
  • The upgraded facility will have an average lifespan of 75 years and will incorporate state-of-the art technology.

Project Need

  • Current growth and anticipated population increases within the service area have created water demands that exceed the daily water treatment capacity.
  • The plant facilities, structures and operating equipment are approaching the end of their life span and need to be upgraded or replaced to ensure reliability and water quality.
  • San Diego must comply with new Federal Environmental Protection Agency (EPA) Safe Drinking Water Act stricter water quality standards as well as State of California water quality standards.
  • The California Department of Public Health issued a Compliance Order listing what the City of San Diego needed to do to be in compliance with the new EPA regulations now and in the future. California Department of Health Services Compliance Order No. 04-14-96-002 issued in 1997 (PDF: 8.95Mb) The upgrades at the Miramar Plant will ensure that the plant meets these EPA regulations.

Contract Schedule

Contract Name and Overview Construction Timeframe
Early Start Improvements Phase I
  • Construct distribution pipelines, valve vault, tunnel and untreated (raw) water pump station modifications
April 2001 – Jan. 2003
Early Start Improvements Phase II
  • Connect distribution pipeline to existing clearwells
  • Prepare surfaces and grade for work in subsequent contract
  • Construct temporary chemical facilities and new San Diego County Water Authority water feed pipeline
Sept. 2002 – Feb. 2005
Contract A
  • Construct new filters, rapid mix facility, de-aeration basin
  • Construct chlorine facility, ozonation structure, chemical buildings
  • Build the administration building and other structures
  • Build mechanical and electrical equipment and piping connecting the new facilities
Aug. 2003 – Dec. 2007
Contract B
  • Construct new high-efficiency flocculation and sedimentation basins
  • Demolish existing filters, flocculation and sedimentation basins
  • Demolish existing operations building and other structures
Nov. 2007 – Dec. 2009
Contract C
  • Construct ozone disinfection facilities
May 2008 – Mar. 2010
Contract D
  • Standard Urban Stormwater Mitigation Plan
  • Retaining Wall and Drainage
  • Landscaping and Water Conservation Irrigation System
  • Fencing
October 2011-Early 2013

Contact Us

If you are interested in learning more about this project, please e-mail us at engineering@sandiego.gov.