Water Production Bureau Divisions

Filtration

The Water Filtration Division handles the operation of chemical storage, mixing, and settling basins, and the filter and backwash system. Filter plant operators work rotating shifts, with one operator on duty at all times to monitor the operation of all treatment equipment, perform laboratory tests, and make adjustments as needed to meet water demands that vary with the seasons, weather, and the time of day. Maintenance personnel perform maintenance and repairs at 24 filters, chemical feeders, control equipment, motors, pipe systems, and other related systems to provide reliable service.

Maintenance is performed twice per year on the flocculating equipment, settling basins, and detention tanks. The sludge cleaned from the settling basins is pumped through an 8" force main into a larger interceptor sewer. This sludge is then treated and disposed of by the Metropolitan Water Reclamation District of Greater Chicago.

The Water Chemist monitors and tests the quality of the water at various stages throughout the treatment process. Our laboratory is certified to perform bacteriological analysis, turbidity, pH, and fluoride sample analysis. Changes in chemical feed rates are made by the Chief of Filtration and the Water Chemist to provide water of the best possible quality with the lowest expenditure of chemicals.

Pumping

The Pumping Division operates the low lift (raw water - pictured at right) and high lift (finished drinking water - pictured below) pumping units. The six low lift pumps, with a rated capacity of 135 million gallons per day, take water from the intake system and pump it to the treatment plant. Eight high lift pumps, with a rated capacity of 147 million gallons per day, pump the finished drinking water to the distribution system. Water plant operators, working rotating shifts every week, provide round-the-clock supervision. The master mechanics maintain and repair the pumping units, hydraulic and electric controls, instruments, electric switchgear, standby gas-powered engines, plant heating system, pipe systems, buildings, and grounds.

The division operates and maintains four booster pumping stations with seven pumps, two 4.9 million-gallon storage tanks, one 5 million-gallon storage tank, and one 7.5 million-gallon storage tank. All equipment is remotely controlled over leased telephone lines to maintain pressure in the distribution system. The Division also provides pumping to the Northwest Water Commission, and remotely controls an in-line booster station with three booster pumps and control valves at the Northwest Water Commission reservoir located in Des Plaines.

The Pumping Division pumps an average of 38 million gallons of water from Lake Michigan each day through three intake pipes and out to customers in Evanston, Skokie, the Northwest Water Commission, and the Morton Grove Niles Water Commission.

Distribution

The water distribution system consists of 156 miles of water main, 1,477 fire hydrants, 2,067 distribution system valves, as well as almost 15,000 service connections. The Distribution Division manages the operation, maintenance, and repair of Evanston’s water mains, valves, fire hydrants, and the City’s portion of water service lines.  The City's portion of the customer service line is from the water main to the shut-off valve, which is usually located in the parkway. Property owners are responsible for the maintenance and repair of the customer service line from the shut-off valve in the parkway into the property.

This includes repairing water main breaks and water service leaks, and installing new valves, hydrants, and water mains to improve the operation and efficiency of Evanston’s water distribution system.  Annual maintenance programs administered by this division include water main leak surveying, valve exercising, and fire hydrant testing.  The Distribution Division also performs routine water quality sampling in buildings throughout Evanston and administers the City’s cross connection control program.  These two programs ensure that water remains safe to drink after leaving the water treatment plant.