Uranium, arsenic, and nitrate were the inorganic constituents that were most frequently detected at high concentrations, mostly in shallower wells. High and moderate concentrations of arsenic were detected in deeper wells.
Results of a survey of contaminants in untreated groundwater in this area. Arsenic and boron were the two trace elements detected most frequently at concentrations greater than the benchmarks.
Six elements with human-health concerns were detected at high concentrations: arsenic, boron, fluoride, molybdenum, strontium, and vanadium. Lead was present at moderate concentrations.
This study of untreated groundwater indicates the number of samples in which inorganic or organic constituents occur in high or moderate in concentration. The study does not indicate significant problems in groundwater quality here.
Summary of chemical constituents of ground water that are of concern to human activity in this area. Arsenic is the constituent that occurs most frequently in high concentrations.
Vanadium and boron were detected at high and moderate concentrations in this area. High concentrations for these constituents were detected almost exclusively in samples collected in the Temecula Valley study area.
Organic solvents are the chief concern in this area, which has given rise to a systematic program of monitoring and water treatment. This study shows relatively recent results.
The constituent present at high concentrations in the greatest proportion of the primary aquifer system was TDS, which is an indicator of salinity. Perchlorate was also present at moderate concentration in 42% of samples.
U.S. Department of the Interior |
U.S. Geological Survey