Water Relief
By Tony Illia

Southern Nevada attracts 8,000 new residents a month and is one of the country's fastest growing regions. North Las Vegas and Henderson were the nation's second- and third-fastest growing cities from April 2000 to July 2002, according to the U.S. Census Bureau.

All that growth means an added demand for water.

To keep up, the Southern Nevada Water Authority is expanding its raw- water pumping system at Saddle Island, Lake Mead, which supplies 81 percent of the Las Vegas Valley with drinking water. Raw water is drawn from Lake Mead and then filtered and disinfected at either the 33-year-old Alfred Merritt Smith Water Treatment Plant or the 2-year-old >> River Mountains Water Treatment Facility. It's then pumped throughout Las Vegas Valley via a 100-mi.-long pipeline network.

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MMC Inc. of North Las Vegas, is currently performing a $32 million raw- water pumping expansion that will enable the River Mountains Facility to double its treatment capacity from 150 million gallons of water a day. Scheduled to finish Oct. 15, 2005, the project entails placing 10 vertical, 4,000-horsepower pumps at the Saddle Island Pumping Station, plus 12 horizontal pumps at two booster stations that will carry the water onto the River Mountains plant.

"This phase will bring the treatment capacity of River Mountains up to 300 million gallons a day," said Gina Nielson, SNWA's engineering manager. "This capacity, as well as the 600 million gallons a day at the Alfred Merritt Smith Plant will meet the valley's demands through 2025."

At Saddle Island, MMC must modify the existing facility by demolishing 10 existing shaft wells and rebuilding them 100 -ft. -deeper. A 50,000-lb. overhead crane will be used to lift and lower the pumps into place, with the heaviest piece weighing 38,000 lbs. MMC will additionally install a 120-ft.-long by 20-ft.-tall surge tank that will capture water back flow in case of a plant shut-down. Acme Electric, North Las Vegas, is performing the pump wiring.

"The tricky part will be installing the last pumps due to the confined space inside the station," said Eddie Urioste, MMC's project manager. "The project will have about 30 people working onsite at the height of construction."

The project also calls for placing six 3,000-horsepower horizontal pumps at a booster station across from the Alfred Merritt Smith plant as well as six 4,000-horsepower horizontal pumps at the boosting station near Lake Las Vegas in Henderson.

The added capacity propels the raw water from Lake Mead onto the River Mountains Water Treatment Facility, where it's treated and distributed throughout the Las Vegas Valley. Montgomery Watson Harza, of Broomfield, Colo. and CH2M Hill Cos. Ltd. of Denver, are the joint-venture project engineers under the name MW/CH2M Hill.

"The initial pump stations were built a few years ago, but this brings them up to full capacity," said Ted Davis, project engineer with MW/CH2M Hill.

Pump installation will require six full shutdowns - ranging from two weeks to one month - at the pumping and booster stations. Contractors Cargo Co. of Compton, Calif., will transport the pumps in a single move with a heavy-duty tractor-trailer rig. The pumps, which weigh a combined 300,000 lbs., must be moved more than 400 mi. from Salt Lake City to Lake Mead.

The 17-month raw- water pumping expansion is part of SNWA''s $2.2 billion Capital Improvement Plan, which consists of a series of infrastructure projects aimed at improving water quality and reliability. Scheduled through 2017, the program is funded by a quarter-cent sales tax approved by Clark County voters in 1998.