Southern Nevada Water Authority

Nevada City, Nevada, United States

Southern Nevada Water Authority

Nevada City, Nevada, United States
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News Article | August 16, 2017

FILE - In this July 28, 2014 file photo, lightning strikes over Lake Mead near Hoover Dam at the Lake Mead National Recreation Area in Arizona. Federal water managers are due to release a crucial report Tuesday projecting whether Arizona and Nevada will face restrictions next year and in 2019 on drinking water supplies from the Lake Mead reservoir on the Colorado River. (AP Photo/John Locher, File) LAS VEGAS (AP) — Heavy winter snows in the Rocky Mountains have rescued the thirsty Western U.S. for another year. U.S. water managers said Tuesday there will be no water cutbacks in 2018 for millions of residents and farmers served by the Lake Mead reservoir on the Colorado River that lies behind the Hoover Dam. "The projection indicates there is no chance of shortage in 2018," said Rose Davis, spokeswoman for the U.S. Bureau of Reclamation. "Zero." January water levels are expected to be 8 feet (2.5 meters) above the point that triggers a drought-shortage declaration on the lake, according to a 24-month projection by the water system management agency. "That's good news for everybody in the basin," said Chuck Cullom, manager of Colorado River programs for the Central Arizona Project, which uses water from the river. The Arizona system serves a heavily populated region that includes the state's largest cities: Phoenix, Tucson and Mesa. The project would be among the first hit by cutbacks in the event of a shortage, although officials say farmers would be affected before cities. The report is a turnabout from a year ago, when the Bureau of Reclamation projected a 50-50 chance the lake would fall just below the shortage point of 1,075 feet (330 meters) above sea level. Under interstate agreements governing the river's use, a shortage declaration would force officials to cut some water to Arizona and Nevada. No official shortage has ever occurred. Overall, the river serves more than 40 million people in cities, farms and tribes in Arizona, California, Colorado, Nevada, New Mexico, Utah and Wyoming. Mexico also gets a share. Conservation and water-banking programs involving Mexico, California, Arizona and Nevada were another big reason the largest constructed reservoir in the U.S. will not fall below the drought shortage point, Davis said. Water banking allows users to leave some of their water in Lake Mead for later use, with restrictions. Combined, conservation and water banking have added about 10 feet (3 meters) to the lake level. "That's substantial, and I think great evidence of the fact that water conservation is possible and can help protect water users from shortages," said Jennifer Pitt, Colorado River Program director for the National Audubon Society. "I think it's a promising sign for the future. It probably needs to be scaled up," she said. Cullom, of the Central Arizona Project, agreed that more will be required in the future. "The persistent drought on the Colorado River system has forced us to look long and hard on how we use water and what the long-term future of our reliance on the Colorado River brings in the face of a warmer or drier climate," he said. Snowmelt from heavy snowfall from mountains in Colorado, Utah and Wyoming also boosted the lake's water level. "We had a good water year — 113 percent of average," Davis told The Associated Press. "That raised our capacity in the whole system from 51 to 57 percent." The report projects a 31 percent chance of a shortage declaration in January 2019. A 1922 interstate agreement allocates a combined 15 million acre-feet of water to the states and Mexico. An acre-foot is about 326,000 U.S. gallons (1.2 million liters), enough to serve two typical homes for a year in the U.S. West. More than 16 years of drought have taken a toll on Lake Mead, which is currently just 38 percent full while farmers withdraw water to irrigate summer crops. But Lake Powell, another huge reservoir on the Colorado River upstream from Mead, has improved to 63 percent capacity. That will provide options for water managers who control the water flow from Powell to Mead. A drought shortage declaration would cut 11.4 percent of Arizona's promised 2.8 million acre-feet (3.4 trillion liter) allocation, and 4.3 percent of Nevada's 300,000 acre-feet (370 billion liters). The amount of water at stake combined would serve more than 625,000 homes. Las Vegas, which draws 90 percent of its water from Lake Mead, might not feel much effect from a shortage because conservation and reuse have cut the city's consumption by about 25 percent, Southern Nevada Water Authority officials say. "We're pleased to see another year when we're not in shortage. But we weren't really surprised by that outcome," Colby Pellegrino, the authority's director of water resources, said Tuesday. Even if a shortage is declared, California will be able to draw its full 4.4 million acre-foot allocation from the river.

LOS ANGELES--(BUSINESS WIRE)--A project using thermal cameras to analyze and adjust water needs and another venture evaluating water-efficient dipper wells for restaurants and ice cream shops are among the latest to receive competitive grants focused on discovering the next generation of water-saving devices and technologies in the West. The Metropolitan Water District of Southern California partnered with the Central Arizona Project, Southern Nevada Water Authority, U.S. Environmental Protection Agency and the U.S. Bureau of Reclamation to help fund 10 projects in the most recent round of Innovative Conservation Program (ICP) grants. The program—which includes Southern California Gas Co. and the nonprofit conservation group, Western Resource Advocates—seeks to advance water-saving efforts by finding new and innovative methods for using water more efficiently. “Western states need to build and sustain resilience to droughts,” said Tomás Torres, EPA’s water division director for the Pacific Southwest. “By supporting the ICP, we’re investing in innovative solutions to help communities meet the challenges of tomorrow—today.” This $560,000 ICP cycle focused on water-saving devices, technologies and strategy proposals that address the water/energy nexus. Awards were given in two funding categories: up to $30,000 and between $30,000 and $100,000. A total of 96 proposals were evaluated through a competitive review process based on project innovations, a water/energy saving and research plan, market impact potential, cost effectiveness, ICP focus and project preparedness. While California’s drought has ended, Metropolitan General Manager Jeffrey Kightlinger noted the West continues to grapple with drought in the Colorado River Basin, which has now stretched into a 17th year. “You don’t need a crystal ball to predict that our future depends on using water wisely and efficiently today,” Kightlinger said. “This program fosters fresh and innovative approaches and inspires creative ideas and strategies to reduce water use.” Ted Cooke, general manager of the Central Arizona Project, said, “There’s no better time than the present for innovation in conservation. As the Colorado River continues to suffer, and the Southwest lives under constant threat of shortage—we hope these grants serve as the impetus for change in our communities, as well as the launching pad for inventive solutions.” Since Metropolitan and Reclamation began the ICP in 2001, the program has awarded 57 grants totaling $1.85 million during the first five two-year funding cycles. Overall, the ICP has yielded 358 proposals totaling $33.4 million in funding requests from public agencies, community-based organizations, private companies, entrepreneurs, research institutes and equipment manufacturers. “As water managers, we are always interested in new strategies and tactics that can be utilized to increase water efficiency,” said John Entsminger, SNWA general manager. “With this program’s platform, we work directly with the innovators to help foster new water-saving technologies or research aimed at reducing water demands and increasing efficiency of Colorado River water use.” Inventive approaches funded in previous cycles include an analysis of plant sensor-based irrigation in vineyards for both wine quality and yield and several projects on soil amendments that maintain the health of grass while significantly minimizing the amount of water applied. Additional past projects include the development of a pressurized water broom that replaces the need to use a hose to clean patios, driveways and other large surface areas, saving up to 250,000 gallons of water over its lifetime, and an X-ray film-processing unit that recycles more than 90 percent of the 1 million gallons of water a typical machine uses in a year in a hospital or medical center. “Water conservation is the largest new supply available to bring water security to the Colorado River Basin. This program looks to accelerate cutting-edge techniques that produce water savings for the benefit of all,” said Bart Miller, Western Resource Advocates’ Healthy Rivers Program director. More information on the Innovative Conservation Program, including lists of past projects, is available at Frontier Energy, Inc. (Oakland, CA)—Dipper wells replacement study Evaluation of water and energy savings potential of replacing dipper wells in restaurants and ice cream shops with more efficient technologies. Analysis will normalize water and energy use to metrics including site square footage, operating hours, number of seats, and any other appropriate metrics. Frontier Energy, Inc. (Oakland, CA)—Pre-rinse operations in commercial kitchens Evaluation of water and energy use of pre-rinse operations in commercial kitchens including the use of scrappers, troughs, hand scrapping, disposers, pulpers, hose use or a combination of several practices. Monitoring will include analysis of staff operations to identify opportunities to reduce waste. Cal Poly Pomona (Pomona, CA)—Solar decentralized graywater treatment unit Development of a low-cost, robust, decentralized, and solar-driven graywater treatment unit for non-potable use for single-family residential dwellings. Cal State Long Beach (Long Beach, CA)—Effective water reuse in cooling tower systems Evaluation of cooling tower wastewater treatment by ion exchange. Cost analysis on water savings from cooled water reuse will also be performed. Watershed Conservation Authority (Azusa, CA)—Cocoon technology for California native trees and shrubs Evaluate the water savings achieved using the Cocoon technology in the establishment of Southern California native trees and shrubs. University of Arizona (Tucson, AZ)—Landscape drip schedule app for the Southwest Continue the previous project that developed and evaluated a landscape drip schedule app ( adding more features to enhance user options and improve flexibility. Cal State Fullerton (Fullerton, CA)—Measuring sap flow in avocado to reduce irrigation Evaluate water savings of using sap flow measurement to establish the actual water needs of 4-year-old Hass avocado trees. Biolargo (Westminster, CA)—Wastewater re-use in food industry Evaluate disinfection and decontamination capabilities of advanced oxidation reactor for water re-use in poultry processing plant. APANA (Bellingham, WA)—Data driven cooling tower optimization study Evaluate water savings by using prescriptive analytics in cooling towers. EyeOn18 (Beaverton, OR)--Drone imagery utilization in golf courses Investigate the use of drones to optimize irrigation management practices in golf courses.

Inyang M.,Southern Nevada Water Authority | Dickenson E.R.V.,Southern Nevada Water Authority
Chemosphere | Year: 2017

Bench- and pilot-scale sorption tests were used to probe the performance of several biochars at removing perfluoroalkyl acids (PFAA) from field waters, compared to granular activated carbon (GAC). Screening tests using organic matter-free water resulted in hardwood (HWC) (Kd = 41 L g−1) and pinewood (PWC) (Kd = 49 L g−1) biochars having the highest perfluorooctanoic acid (PFOA) removal performance that was comparable to bituminous coal GAC (Kd = 41 L g−1). PWC and HWC had a stronger affinity for PFOA sorbed in Lake Mead surface water (KF = 11 mg(1−n) Ln g−1) containing a lower (2 mg L−1) dissolved organic carbon (DOC) concentration than in a tertiary-filtered wastewater (KF = 8 mg(1−n) Ln g−1) with DOC of 4.9 mg L−1. A pilot-scale study was performed using three parallel adsorbers (GAC, anthracite, and HWC biochar) treating the same tertiary-filtered wastewater. Compared to HWC, and anthracite, GAC was the most effective in mitigating perfluoropentanoic acid (PFPnA), perfluorohexanoic acid (PHxA), PFOA, perfluorooctane sulfonic acid (PFOS), and DOC (45–67% removed at 4354 bed volumes) followed by HWC, and then anthracite. Based on bench- and pilot-scale results, shorter-chain PFAA [perfluorobutanoic acid (PFBA), PFPnA, or PFHxA] were more difficult to remove with both biochar and GAC than the longer-chain, PFOS and PFOA. © 2017 Elsevier Ltd

David Holbrook R.,U.S. National Institute of Standards and Technology | Motabar D.,U.S. National Institute of Standards and Technology | Quinones O.,Southern Nevada Water Authority | Stanford B.,Southern Nevada Water Authority | And 2 more authors.
Environmental Pollution | Year: 2013

The increased use of titanium dioxide nanoparticles (nano-TiO2) in consumer products such as sunscreen has raised concerns about their possible risk to human and environmental health. In this work, we report the occurrence, size fractionation and behavior of titanium (Ti) in a children's swimming pool. Size-fractionated samples were analyzed for Ti using ICP-MS. Total titanium concentrations ([Ti]) in the pool water ranged between 21 μg/L and 60 μg/L and increased throughout the 101-day sampling period while [Ti] in tap water remained relatively constant. The majority of [Ti] was found in the dissolved phase (<1 kDa), with only a minor fraction of total [Ti] being considered either particulate or microparticulate. Simple models suggest that evaporation may account for the observed variation in [Ti], while sunscreen may be a relevant source of particulate and microparticule Ti. Compared to diet, incidental ingestion of nano-Ti from swimming pool water is minimal. © Published by Elsevier Ltd.

Rosario-Ortiz F.L.,Southern Nevada Water Authority | Wert E.C.,Southern Nevada Water Authority | Snyder S.A.,Southern Nevada Water Authority
Water Research | Year: 2010

Advanced oxidation treatment using low pressure UV light coupled with hydrogen peroxide (UV/H2O2) was evaluated for the oxidation of six pharmaceuticals in three wastewater effluents. The removal of these six pharmaceuticals (meprobamate, carbamazepine, dilantin, atenolol, primidone and trimethoprim) varied between no observed removal and >90%. The role of the water quality (i.e., alkalinity, nitrite, and specifically effluent organic matter (EfOM)) on hydroxyl radical ({radical dot}OH) exposure was evaluated and used to explain the differences in pharmaceutical removal between the three wastewaters. Results indicated that the efficacy of UV/H2O2 treatment for the removal of pharmaceuticals from wastewater was a function of not only the concentration of EfOM but also its inherent reactivity towards {radical dot}OH. The removal of pharmaceuticals also correlated with reductions in ultraviolet absorbance at 254 nm (UV254), which offers utilities a surrogate to assess pharmaceutical removal efficiency during UV/H2O2 treatment. © 2009 Elsevier Ltd. All rights reserved.

Woods G.C.,Southern Nevada Water Authority | Dickenson E.R.V.,Southern Nevada Water Authority
Journal - American Water Works Association | Year: 2015

The complete database of results from the second Unregulated Contaminant Monitoring Rule (UCMR2) was analyzed in depth for N-nitrosodimethylamine (NDMA) occurrence across the United States and analyzed for trends associated with factors reported. Disinfectant type, source waters, regional variability, population density, and seasonal variability were all examined for potential impacts on NDMA. Detectable levels of NDMA were found in 17% of samples and 25% of treatment plants. The other five listed nitrosamines were detected in less than 1% of samples. The strongest factor found positively associated with NDMA occurrence was chloramine use. Likewise, the use of surface waters was found to be linked to NDMA occurrence such that surface waters (even when decoupled from chloramine use) demonstrated elevated levels of NDMA over groundwater sources. No clear seasonal trends could be deciphered, but data supplied from utilities servicing fewer than 10,000 customers provide evidence that smaller utilities have some of the most extreme NDMA levels and subsequently may have a difficult time meeting any future NDMA regulation. © 2015 American Water Works Association.

Vanderford B.J.,Southern Nevada Water Authority | Mawhinney D.B.,Southern Nevada Water Authority | Trenholm R.A.,Southern Nevada Water Authority | Zeigler-Holady J.C.,Southern Nevada Water Authority | Snyder S.A.,University of Arizona
Analytical and Bioanalytical Chemistry | Year: 2011

Proper collection and preservation techniques are necessary to ensure sample integrity and maintain the stability of analytes until analysis. Data from improperly collected and preserved samples could lead to faulty conclusions and misinterpretation of the occurrence and fate of the compounds being studied. Because contaminants of emerging concern, such as pharmaceuticals and personal care products (PPCPs) and steroids, generally occur in surface and drinking water at ng/L levels, these compounds in particular require such protocols to accurately assess their concentrations. In this study, sample bottle types, residual oxidant quenching agents, preservation agents, and hold times were assessed for 21 PPCPs and steroids in surface water and finished drinking water. Amber glass bottles were found to have the least effect on target analyte concentrations, while high-density polyethylene bottles had the most impact. Ascorbic acid, sodium thiosulfate, and sodium sulfite were determined to be acceptable quenching agents and preservation with sodium azide at 4 °C led to the stability of the most target compounds. A combination of amber glass bottles, ascorbic acid, and sodium azide preserved analyte concentrations for 28 days in the tested matrices when held at 4 °C. Samples without a preservation agent were determined to be stable for all but two of the analytes when stored in amber glass bottles at 4 °C for 72 h. Results suggest that if improper protocols are utilized, reported concentrations of target PPCPs and steroids may be inaccurate. © Springer-Verlag 2011.

Vidal-Dorsch D.E.,Southern California Coastal Water Research Project | Bay S.M.,Southern California Coastal Water Research Project | Maruya K.,Southern California Coastal Water Research Project | Snyder S.A.,Southern Nevada Water Authority | And 3 more authors.
Environmental Toxicology and Chemistry | Year: 2012

The occurrence and concentrations of contaminants of emerging concern (CECs) were investigated in municipal effluents and in marine receiving water. Final effluent from four large publicly owned treatment works (POTWs) and seawater collected near the respective POTW outfall discharges and a reference station were collected quarterly over one year and analyzed for 56 CECs. Several CECs were detected in effluents; naproxen, gemfibrozil, atenolol, and tris(1-chloro-2-propyl)phosphate were the compounds most frequently found and with the highest concentrations (>1μg/L). Gemfibrozil and naproxen had the highest seawater concentrations (0.0009 and 0.0007μg/L) and also were among the most frequently detected compounds. Effluent dilution factors ranged from >400 to approximately 1,000. Fewer CECs were detected and at lower concentrations in seawater collected from the reference station than at the outfall sites. Effluent concentrations for some CECs (e.g., pharmaceuticals) were inversely related to the degree of wastewater treatment. This trend was not found in seawater samples. Few temporal differences were observed in effluent or seawater samples. Effluent CEC concentrations were lower than those currently known for chronic toxicity thresholds. Nevertheless, the evaluation of potential chronic effects for CECs is uncertain because aquatic life toxicity thresholds have been developed for only a few CECs, and the effluent and seawater samples had compounds, such as nonylphenol, known to bioaccumulate in local fish. Additional data are needed to better understand the significance of CEC presence and concentrations in marine environments. © 2012 SETAC.

Marti E.J.,Southern Nevada Water Authority | Marti E.J.,University of Nevada, Las Vegas | Pisarenko A.N.,CA Technologies | Peller J.R.,Indiana University Northwest | Dickenson E.R.V.,Southern Nevada Water Authority
Water Research | Year: 2015

Nitrosamines are a class of toxic disinfection byproducts commonly associated with chloramination, of which several were included on the most recent U.S. EPA Contaminant Candidate List. Nitrosamine formation may be a significant barrier to ozonation in water reuse applications, particularly for direct or indirect potable reuse, since recent studies show direct formation during ozonation of natural water and treated wastewaters. Only a few studies have identified precursors which react with ozone to form N-nitrosodimethylamine (NDMA). In this study, several precursor compound solutions, prepared in ultrapure water and treated wastewater, were subjected to a 10M excess of ozone. In parallel experiments, the precursor solutions in ultrapure water were exposed to gamma radiation to determine NDMA formation as a byproduct of reactions of precursor compounds with hydroxyl radicals. The results show six new NDMA precursor compounds that have not been previously reported in the literature, including compounds with hydrazone and carbamate moieties. Molar yields in deionized water were 61-78% for 3 precursors, 12-23% for 5 precursors and <4% for 2 precursors. Bromide concentration was important for three compounds (1,1-dimethylhydrazine, acetone dimethylhydrazone and dimethylsulfamide), but did not enhance NDMA formation for the other precursors. NDMA formation due to chloramination was minimal compared to formation due to ozonation, suggesting distinct groups of precursor compounds for these two oxidants. Hydroxyl radical reactions with the precursors will produce NDMA, but formation is much greater in the presence of molecular ozone. Also, hydroxyl radical scavenging during ozonation leads to increased NDMA formation. Molar conversion yields were higher for several precursors in wastewater as compared to deionized water, which could be due to catalyzed reactions with constituents found in wastewater or hydroxyl radical scavenging. © 2014 Elsevier Ltd.

News Article | November 18, 2016

Paul Grant owns a Henderson landscaping company in Las Vegas, Nevada and he has issued a friendly reminder to all residents not to forget to switch their irrigation systems to the winter schedule. This is in light of the mandatory watering restrictions that limits landscape irrigation in southern Nevada to just one designated day per week. The restriction came into effect on November 1st and they will be enforced right up until February 28th. “These winter watering restrictions also apply to drip irrigation systems and residents that don’t comply could be hit with a water waste fine. As the restrictions came into effect on November 2nd, most people will already have taken action. However, while carrying out my weekly landscape maintenance jobs in Henderson, I’ve noticed that some residents still haven’t made the switch. Failure to comply leads to all kinds of problems considering the shortages of water in and around Las Vegas,” Paul noted. Grant says “Don’t water on days that are rainy and/or windy as water can be dispersed in the wrong direction, and soil can become over saturated on wet days. By simply turning off sprinklers during these weather conditions can result in a saving of about 500 gallons of water. Homeowners must check what watering group they fall into which will determine the day of the week that they’re permitted to run their systems. They can do this by checking their monthly water bill or by logging onto the Southern Nevada Water Authority (SNWA) website.” Landscaping in Henderson and the rest of Las Vegas has become all the more topical in recent months as the water crisis in this area becomes more of a concern. The state has experienced a very warm, dry summer again this year, which further increases the probability that there will be a water shortage in Lake Mead by as soon as 2018. This has sparked wide-spread concern, so switching irrigation systems to their winter schedules couldn’t be more important than it is now. For more information, please visit

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