Water Treatment Plant

Membrane Microfiltration Water Treatment Plant
River Diversion Improvements


Membrane Microfiltration Water Treatment Plant

  • Single story residential style building, 68 ft. wide, 270 ft. long, 28 ft. tall
  • Building sits over a two million gallon “clearwell” substructure
  • Initial size sufficient to treat 17 million gallons per day (mgd) with 12 microfiltration units
  • Facility sized to ultimately treat 22 mgd, with 16 microfiltration units

American River Diversion System Improvements

  • Replaced existing pipelines that connected three Ranney Collectors with 2,200 ft. of 48-inch diameter pipe
  • Ranney water now flows by gravity to north side of American River
  • Removed above ground portion of Ranney Collectors to improve American River aesthetics
  • Removed electrical vault providing power to Ranney 3
  • Microtunneled beneath the American River to the microfiltration plant site


  • Three microtunnel drives – longest 970 ft.
  • Microtunnel drive beneath the American River – 700 ft.
  • Average depth – 45 ft., ranges from 30 ft. below the American River to 90 ft. entering the 100 ft. deep caisson at the water treatment plant

Vertical Caissons/Shafts

  • 28 ft. diameter by 60 ft. deep caisson (on south side of American River) near Ranney 2 served as “jacking” shaft for all microtunnel drives
  • 20 ft. diameter by 100 ft. deep caisson (on north side of American River) at the membrane filtration plant
  • Two 16 ft. diameter by 45 ft. deep temporary receiving shafts to retrieve microtunneling machine

Membrane Filters

  • 12 primary membrane skids – 1.8 million hollow fibers per skid
  • 2 solid membrane skids – 960,000 hollow fibers per skid
  • 2 tertiary membrane skids – 120,000 hollow fibers per skid
  • These membrane filters remove particulates 0.2 microns or larger

Project Cost: $24.13 million

Construction Completion Date: August 2001

Bajamont Water Treatment Plant Expansion Complete

  • Bajamont Water Treatment Plant’s current production capacity has increased to 22 million gallons per day.
  • Expansion project completed in April 2008.  Full production test was completed in May 2008.
  • Project included the addition of two new chemical feed systems, an energy efficient compressor and 4 additional microfiltration units.
  • The expansion allows the District to use only two groundwater sources during high demand summer months.
  • Expansion project was completed on time and within budget.
  •  Prop 50 grant money totaling $410,000 assisted with construction costs.