As simple as it sounds, a single, fractured molecule of oxygen – one of the most common elements on Earth – is helping to transform Southern Nevada’s Lake Mead water supply into a life-sustaining commodity that’s safer, tastier and sweeter smelling to Las Vegas Valley resident’s sensitive noses. But, like most things, it not as simple as it sounds. In fact, the $14.1 million worth of electrical discharging equipment being used to create ozone – an oxygen (02) compound with an added molecule (03) – is but a small part of an overall $2.1 billion package of improvements. Starting this month, the new facility will bring another 150 million gallons of Lake Mead water to the River Mountains Water Treatment Facility (WTF) in Henderson every day. To put 150 million gallons in perspective, that’s enough water to fill 15,000 backyard swimming pools or to fill a 1-foot-wide by 1-foot-deep trough 3,797 miles long – from Seattle to the Panama Canal with 150 miles to spare.
“The contractors made a commitment to have treated water delivered this June,” said Marc Jensen, director of engineering for the Southern Nevada Water Authority (SNWA), the nonprofit government agency overseeing construction of the $183 million project. “They’re working hard to meet that date so we can deliver water before the peak summer demand hits us. That’s what we’re focusing on now.”
The River Mountains site encompasses 400 acres of desert at the western base of the mountain range with the same name, but only half has been developed so far. SNWA has reserved the remainder for future development as the need warrants. A second construction phase, scheduled for completion in 2006, will double the number of gallons leaving the treatment facility daily. At full build-out capacity, River Mountains will be able to produce 600 million gallons of potable water per day.
SNWA’s $2.1 billion Capital Improvements Program (CIP) was launched in 1995 and includes not only the River Mountains WTF, but expansion of the 31-year-old lakeside Alfred M. Smith WTF from 400 million gallons per day to 600 million gallons per day, installation of ozone treatment equipment at both facilities, a second underwater intake costing $82.7 million, two pumping and booster stations, seven miles of aqueduct and tunnels up to nine feet in diameter. It also involves more than 100 miles of pipeline used to deliver the ozone-treated water to the authority’s four water-selling customers – the Las Vegas Valley Water District and the cities of North Las Vegas, Henderson and Boulder City.
The River Mountains WTF receives its raw, untreated water through the original Lake Mead intake and pipeline built in the 1960s. The water disinfected by the ozone process recently installed at the Alfred M. Smith WTF flows directly into the valley-wide transmission network via a new, $42.7 million aqueduct/tunnel that had to be burrowed through solid rock. The plant sits more than 1,000 feet higher than the lake’s elevation, which requires power-hungry pumps to push the water uphill for treatment. According to SNWA General Manager Pat Mulroy, the newly built intake, the so-called “second straw,” became essential, in terms of reliability, as the Valley continued its explosive growth in the ’90s.
“When the Southern Nevada water system was first built, the ratio between Colorado River water and local groundwater [from wells] was 60-40. If something happened on the river, you could always fall back on your wells to provide the water service,” Mulroy said. “In recent years, the percentage has crept up to 85 percent river water. Until we added the second straw and brought the second tunnel on line, all river water coming into Southern Nevada came through a single pipe. If something had happened to that one pipe, we would have had a disaster in Southern Nevada. We couldn’t continue to let that happen.”
Up until this year, SNWA disinfected its water only with chlorine, a long-lasting and effective way to rid lake water of many potentially harmful bacteria and microscopic organisms. However, chlorination can create a foul taste and smell to some people’s senses. The ozonation process of disinfecting water involves injecting untreated water with colorless ozone gas released through ceramic diffusers similar to upside-down shower heads with tiny holes. It results in more palatable water, significant reductions in after-treatment chlorine use and the elimination of cryptosporidium, a microorganism that causes a discomforting intestinal disease that created a scare in Southern Nevada nearly 10 years ago.
“At that time, the CDC (U.S. Centers for Disease Control) felt [the outbreak] was attributable to the water, but it’s in all the rivers and streams and it hadn’t been an issue here before,” Mulroy related. “So we looked at various treatment methodologies. Even though we have always put the water through a very extensive filtration process before delivering it, ozonation adds that additional layer of protection for the customer against tiny bacteria, such as cryptosporidium, that can get through those filter mediums.” Jensen, a 1982 San Diego State University graduate with a degree in civil engineering, said ozone treatment is a most powerful disinfectant when it comes to cryptosporidium, performing much better as a bacteria killer than chlorine.
While the 150 million gallons per day flowing from the River Mountains WTF will slake the Valley’s thirst for the time being, plans are already in the works for doubling the plant’s capacity. The plant’s cost started at $130 million in 1998, but is ending up 41 percent over budget at $183 million because of the added work. However, Jensen said the extra money was well worth it.
“We negotiated a fair price with the contractor, $31.3 million, to do all that heavy structural and civil work as part of Phase 1, so now in the second phase it’s mostly the installation of electrical and mechanical equipment, chemical systems and control systems work,” said Jensen, who started his career in engineering by working as a summer intern for the LVVWD in 1981. “What we did was keep one contractor from working on top of the other, [which] would have been very costly in terms of conflict. It was a big change order and was a fairly big issue for us.”
The River Mountains WTF and the other CIP components, a modern-day engineering feat, required expertise in nearly all land-based engineering disciplines ranging from civil to electrical to mechanical to marine engineering for the underwater drilling of Intake No. 2 – the second straw – which removed 572,000 tons of rock over a 14-month period. According to SNWA’s latest CIP progress report, 17 engineering firms, 34 construction contractors and three procurement contractors have been used on the project since its mid-1995 start.
The $2.1 billion price tag is being financed by 20-year and 30-year tax-free municipal bonds, which, when fully paid off, will result in an adjusted grand total of $5 billion, according to SNWA Controller Matt Thorley. Revenues are being generated by an intricate funding plan with 57 percent being paid by connection charges, 21 percent coming from a regional reliability charge of 5 cents per 1,000 gallons and a reliability surcharge that’s 10 times greater for large commercial customers, with the remaining 28 percent derived from a 1998 voter-approved one-quarter-cent sales tax hike that will be retired when its share of a pre-determined amount is reached.
“With those pieces put in place, we’ve avoided the customer feeling a shock effect of having the costs of those facilities hit. It took a lot of community debate, a lot of community discussion,” Mulroy said. “The citizen’s committee spent a great deal of time looking at how to pay for this because the federal government is no longer in the business of building large water projects in the West. They’re simply not going to do it. To take a project of over $2 billion and get a community of what was then just over 1 million people to begin paying for it was a difficult task.”
The River Mountains facility is the largest public works contract in Nevada’s history and the multi-billion-dollar expense is rivaled in the West by only a few recent major metropolitan water district projects, including the Metropolitan Water District of Southern California’s newly completed $1.9 billion East Side Reservoir in Riverside County. It’s a lot of money for a lot of water.
“The first stage of the Southern Nevada Water System cost the community $400 million and they were just beside themselves,” Mulroy recalled. “Believe me, it took me a while to learn how to say the ‘B’ [billion] word.”