2007 Ground Water Summit

Wednesday, May 2, 2007 : 10:00 a.m.

Vidler Recharge Facility,a Nitrate Case Study: Where It's Coming From —You Might Be Surprised!

Greg Bushner, RG1, David A. Merrill, PE1, Richard K. Glanzman2 and Canda Lorson3, (1)Vidler Water Company, (2)CH2M Hill, (3)URS Corp.

The Vidler Recharge Facility (VRF), located about 70 miles west of Phoenix in western Arizona, is comprised of over 460 acres of surface infiltration basins. The VRF stores excess Central Arizona Project water from the Colorado River and has been in operation since the year 2000. Recharge is approximately 30,000 acre feet annually accounting for facility losses including evaporation. During this time and as compliance with permit conditions from the Arizona Department of Water Resources, on-site monitor wells have been sampled on a quarterly basis for a suite of constituents including Nitrates. The VRF is located on virgin desert lands; however farming activities have occurred for decades on lands east of the facility.

 

            Since monitoring began at the VRF, nitrate levels have increased to over 100 ppm in some down gradient monitor wells. Because of the elevated nitrate levels and to comply with permit conditions, Vidler Water Company has initiated nitrate study to: (1) determine the source of the nitrates, both horizontally and vertically, (2) determine methods to mitigate the high nitrates and the length of time that will be required to do this, (3) develop operational controls or modified designs for the VRF that will decrease nitrogen loading to the aquifer or mitigate the impacts of nitrate in the groundwater, and (4) to evaluate the any impacts that may have occurred to land or other water users in the area.

Greg Bushner, RG, Vidler Water Company Greg Bushner received a B.S. degree in geology from Northern Arizona University, Flagstaff, Arizona, in 1983. He is currently the Chief Hydrogeologist for Vidler Water Company. His consultant career included serving as Practice Leader for Groundwater Resources at URS Corporation from 2002 to 2006, and Associate Hydrogeologist with HydroSystems, Inc. from 1994 to 2002. Mr. Bushner specializes in hydrogeology, artificial groundwater recharge projects, water well drilling and state permitting. Prior to consulting, he was with the Arizona Department of Water Resources from 1985 through 1994. At ADWR he managed the Surface Water/Recharge Section of the Hydrology Division.


The 2007 Ground Water Summit