Rainbow approves scope expansion of Pump Station #1 upgrades

The Rainbow Municipal Water District has opted to expand the scope of its professional services contract with Infrastructure Engineering Corporation for design services to upgrade Pump Station No. 1.

Rainbow's board voted 4-0 Dec. 6, with Rich Bigley absent, to expand the scope of the district's contract with IEC for the additional work. The expanded scope of work increases the contract amount by $61,296 for a total amount of $168,789.

"It's one of our largest pump stations," said Rainbow general manager Tom Kennedy. "We need to make sure it's kept in good working condition."

Pump Station #1 conveys water from the North Zone to the Rainbow Heights Tank which is at 1,967 feet above sea level and has a capacity of 4 million gallons. The Rainbow Heights zone extends north to Pump Station #7 and the Magee Zone and is the sole supply to the Magee Zone. The Rainbow Heights Zone is separated from the Gomez Zone to the east and south by closed valves, although the Rainbow Heights Zone can be used for emergency supply to the Gomez Zone as well as to the Vallecitos Zone and the North Zone.

Pump Station No. 1 includes two 250-horsepower pumps, one 290-horsepower pump, and one 300-horsepower pumps. The four pumps create a total flow capacity of 3,509 gallons per minute.

On Aug. 23, the Rainbow board voted 3-0 with Bigley and Tory Walker absent to approve a design services contract with Infrastructure Engineering Corporation for up to $107,493 to replace the motors on Pump Station No. 1. IEC, which has an Oceanside office, will prepare a full set of plans and specifications including multiple options for upgrades to the pump station.

The upgrades will include replacing the natural gas engines with electric motors and soft start motor control centers on the 290-horsepower and 300-horsepower pumps, which will meet current Air Pollution Control District standards and will also reduce the district's maintenance and electricity consumption costs.

The motor control centers for the two existing electric motors will also be replaced with soft start control panels, the pump station's main incoming electrical panel will be replaced, and an emergency backup gas powered generator with an automatic transfer switch will also be part of the design.

The initial site visit determined that additional work would likely be required. The existing building could have structural issues necessitating rehabilitation if not replacement. Most of the electrical equipment at the station is outside of the building and secured only by a chain-link fence, and the Rainbow district has previously experienced the theft of copper wires from electrical panels at the Huntley pump station.

"We asked the board for a change order to expand the scope of design," Kennedy said. "We want to replace that building."

Two of the four pumps are in the building, so a new building would also allow all four pumps to be enclosed. The expanded scope of work will include the replacement of the existing building with one which can enclose and secure all four of the pumps and the relocation of all electrical panels to within the new building.

"That's just for the design contract," Kennedy said of the Dec. 6 board action. "Then we'll be out to bid on this hopefully by the middle of this year."