MSGID: 1:317/3 63f59a7d   
   PID: hpt/lnx 1.9.0-cur 2019-01-08   
   TID: hpt/lnx 1.9.0-cur 2019-01-08   
    Arsenic contaminates private drinking water wells across the western   
   Great Basin    
    A new study maps risk of elevated arsenic levels in groundwater wells   
   across northern Nevada, northeastern California, and western Utah    
      
     Date:   
         February 21, 2023   
     Source:   
         Desert Research Institute   
     Summary:   
         In the arid and drought-stricken western Great Basin, sparse   
         surface water means rural communities often rely on private   
         groundwater wells.   
      
         Unlike municipal water systems, well water quality in private   
         wells is unregulated, and a new study shows that more than 49   
         thousand well users across the region may be at risk of exposure   
         to unhealthy levels of arsenic in drinking water.   
      
      
         Facebook Twitter Pinterest LinkedIN Email   
   FULL STORY   
   ==========================================================================   
   In the arid and drought-stricken western Great Basin, sparse surface   
   water means rural communities often rely on private groundwater   
   wells. Unlike municipal water systems, well water quality in private   
   wells is unregulated, and a new study shows that more than 49 thousand   
   well users across the region may be at risk of exposure to unhealthy   
   levels of arsenic in drinking water.   
      
      
   ==========================================================================   
   Led by researchers at DRI and the University of Hawai'i Cancer Center and   
   published February 16th in Environmental Science and Technology, the study   
   used data from groundwater wells across the western Great Basin to build   
   a model to predict the probability of elevated arsenic in groundwater,   
   and the location and number of private well users at risk. According   
   to the study, the Carson Desert basin (including the town of Fallon,   
   Nevada), Carson Valley (Minden and Gardnerville, Nevada), and the Truckee   
   Meadows (Reno), have the highest population of well users at risk. The new   
   study builds on previous research showing that 22% of 174 domestic wells   
   sampled in Northern Nevada had arsenic levels exceeding the EPA guideline.   
      
   "What we are finding is that in our region, we have a high probability   
   for elevated arsenic compared to most other regions in the country,"   
   said Daniel Saftner, M.S., a hydrogeologist at DRI and lead author of the   
   study. "And we are seeing that geothermal and tectonic processes that are   
   characteristic of the Great Basin contribute to the high concentrations of   
   naturally occurring arsenic in the region's groundwater."  The region's   
   mountains are also primary sources of arsenic. "As the arsenic- rich   
   volcanic and meta-sedimentary rocks that form the mountains erode,   
   sediment is transported to the valleys below," says Steve Bacon, Ph.D.,   
   DRI geologist and study co-author. Water percolating through the valley   
   floor then carries arsenic into the groundwater. Deeper, older groundwater   
   and geothermal waters tend to have a higher arsenic concentration and   
   can migrate upward along faults and mix with shallow groundwater.   
      
   "We really wanted to better understand the unique geologic factors that   
   contribute to high arsenic in this study," Saftner says. "It's important   
   for us to think about the role of the environment as it pertains to   
   human health - - where we live can influence what our long-term health   
   looks like."  To train and test the predictive model, the research team   
   used data collected through the Healthy Nevada Project, including water   
   samples from 163 domestic wells primarily located near Reno, Carson City,   
   and Fallon. These data were supplemented with 749 groundwater samples   
   compiled from the USGS National Water Information System. The model uses   
   tectonic, geothermal, geologic, and hydrologic variables to predict the   
   probability of elevated arsenic levels across the region.   
      
   Although the U.S. EPA has set an arsenic concentration guideline of 10   
   myg/ L for public drinking water, previous research has shown a range of   
   health effects from long-term exposure to levels above 5 myg/L. Using this   
   concentration as the benchmark, the model and map show that much of the   
   region's groundwater -- particularly in western and central Nevada -- is   
   predicted to have more than a 50% probability of elevated arsenic levels.   
      
   "Community members can use our arsenic hazard map to see what the risk is   
   at their location, which might motivate them to test their well water,"   
   says Monica Arienzo, Ph.D., associate research professor at DRI and   
   study co-author.   
      
   "Then, if they have high levels of arsenic or other contaminants, they   
   can take steps to reduce their exposure, such as installing a water   
   treatment system."  The findings from this study are potentially useful   
   for a range of different applications. "The results can be useful for   
   water utilities or water managers who tap similar shallow aquifers for   
   their water supply," says Saftner, "as well as irrigation wells that   
   source water from these aquifers."  The research team plans to use their   
   model to take a closer look at the health impacts of prolonged arsenic   
   exposure. "Through the Healthy Nevada Project, genetic data and health   
   records are paired with environmental data to help determine whether   
   there are associations between the levels of arsenic in a community's   
   groundwater and specific health outcomes," stated Joe Grzymski, Ph.D.,   
   research professor at DRI and principal investigator of the project.   
      
       * RELATED_TOPICS   
             o Health_&_Medicine   
                   # Vitamin_D # Health_Policy # Medical_Topics #   
                   Chronic_Illness   
             o Earth_&_Climate   
                   # Water # Drought_Research # Hazardous_Waste #   
                   Recycling_and_Waste   
       * RELATED_TERMS   
             o Surface_runoff o Water_purification o Water_scarcity   
             o Groundwater o Fracking o Cholera o Water_pollution o   
             Brackish_water   
      
   ==========================================================================   
   Story Source: Materials provided by Desert_Research_Institute. Note:   
   Content may be edited for style and length.   
      
      
   ==========================================================================   
   Related Multimedia:   
       * Maps_showing_arsenic_contamination   
   ==========================================================================   
   Journal Reference:   
      1. Daniel M. Saftner, Steven N. Bacon, Monica M. Arienzo, Erika Robtoy,   
         Karen Schlauch, Iva Neveux, Joseph J. Grzymski, Michele Carbone.   
      
         Predictions of Arsenic in Domestic Well Water Sourced from Alluvial   
         Aquifers of the Western Great Basin, USA. Environmental Science &   
         Technology, 2023; DOI: 10.1021/acs.est.2c07948   
   ==========================================================================   
      
   Link to news story:   
   https://www.sciencedaily.com/releases/2023/02/230221180102.htm   
      
   --- up 51 weeks, 1 day, 10 hours, 50 minutes   
    * Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)   
   SEEN-BY: 15/0 106/201 114/705 123/120 153/7715 226/30 227/114 229/110   
   SEEN-BY: 229/111 112 113 114 307 317 400 426 428 470 664 700 292/854   
   SEEN-BY: 298/25 305/3 317/3 320/219 396/45   
   PATH: 317/3 229/426