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<br />Las Vegas Area Taps Lake Mead to Satisfy A Growing Thirst (4124/2000)
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<br />. Top Environmental Firms and Engineers, a firm that merged to form an industry leader, Ellerbe Becket.
<br />· Top Desig.n Build Firms Mahal now heads the local Nevada Seniors Coalition and criticizes Mulroy's
<br />· Top eM F!rms (fee) "make-work" project that doubles the county's lake-intake capacity in excess
<br />, Top CM Firms (at risk) of available water.
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<br />MULTIPLICITY Mahal's coalition opposed the I 4~ sales tax increase that
<br />72% of county voters approved anyway in 1998 for water and wastewater
<br />system upgrades. The tax helps fund a multiplicity of water improvements
<br />begun in 1995 for completion by 2017. The projects include a second 600-
<br />million-gallons-per-day intake, as well as related components just completed
<br />on April 23 for $80 million. Nearby at the lakeside Alfred Merritt Smith
<br />Water Facility-an existing treatment plant expanded from 400 mgd to 600
<br />mgd in I 997-work continues today on a $6 I-million addition of ozone
<br />units.
<br />
<br />Beyond the plant loom the roughly 1,900-ft-high River Mountains,
<br />through which crews bored a second 4-mile water tunnel in 1995. On the
<br />other side ofthe mountains in the Las Vegas Valley, work also continues at
<br />the new 300-mgd River Mountains Water Treatment Facility, the $147
<br />million project that includes the controversial change order. System-wide, the
<br />ongoing work also includes the addition of 87 miles of pipeline to the pre-
<br />existing 75 miles.
<br />
<br />Some critics wonder why the system's capacity is being increased in
<br />excess of Nevada's allocation of Colorado River water from Lake Mead.
<br />SNW A recently increased the lake-intake capacity from an initial 600 mgd to
<br />1,200 mgd; and boosted treatment capacity from 400 mgd to 600 mgd, with
<br />plans to expand it again to 900 mgd.
<br />
<br />And such critics complain that use of the second lake intake will
<br />exacerbate the possibility of drawing water mixed with treated effluent.
<br />Federal policy encourages Clark County-with its current 1.3 million
<br />residents-to return treated effluent to the lake. Last year, Mulroy's agency
<br />obtained so-called return-flow credits of 160,000 acre-ft to augment a river
<br />allocation of 300,000 acre-ft. "We're essentially contaminating our own
<br />drinking-water supply in the process of collecting return-flow credits,"
<br />complains a retired lakes expert Larry J. Paulson, 55, a former professor in
<br />the biology department at the University of Nevada, Las Vegas.
<br />
<br />Nevada's annual allocation of300,OOO acre-ft--enough for 1.8 million
<br />people-seemed more than adequate in 1928 when Congress authorized
<br />construction of Hoover Dam to impound Lake Mead. Before construction
<br />began in 1931, when Nevada also legalized gambling, Las Vegas survived as
<br />a rail stop. Natural artesian springs made life possible despite a mere 4 in. of
<br />average annual rainfall. Now the region hosts nearly 34 million tourists
<br />annually.
<br />
<br />The county and the cities of Las Vegas and Henderson empty 120 mgd of
<br />effluent into Las Vegas Wash, according to the Clark County Sanitation
<br />District. The discharge flows into Lake Mead, 8 miles upstream of Saddle
<br />Island where the region draws 85% of its potable water. Although tertiary-
<br />treated to remove nutrients that nourish algae, the effluent contains more total
<br />dissolved salts than the Colorado River. And with a higher density than the
<br />lake, the effluent flows as a plume. At worst, according to Mulroy's SNW A
<br />staff, a remnant of the plume-less than a half meter thick and 95% diluted-
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<br />http://www.enr.comlnew/c42400.asp
<br />
<br />05/15/2000
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