Ambient Groundwater Quality of Ranegras Plan Basin: A 2008-2011 Baseline Study- June 2012
The Arizona Department of Environmental Quality, as part of its Ambient Groundwater Monitoring Program, conducted a baseline groundwater quality study of the Ranegras Plain basin from 2008 and 2011, and has released two versions of the report in print and online: a 63-page report and a condensed 4-page fact sheet. Arizona Revised Statutes 49-225 mandates ongoing monitoring of waters of the state including its aquifers. The study is based on samples collected from 55 sites within the Ranegras Plain groundwater basin, which covers approximately 912 square miles in western Arizona within La Paz County.
According to the report, “Most groundwater pumped in the Ranegras Plain is used for irrigation in the central part of the basin.” As discussed in the report, the study determined that the most important factor affecting water quality in the Ranegras basin is the recharge age of the groundwater. Concerns with drinking water sources in the area involve recent recharge, which is generally preferred over older recharge. The study resulted in recommendations from ADEQ for private domestic well owners in the basin to have their drinking water tested for contaminants particularly arsenic, chromium, fluoride, and nitrate by a certified laboratory.