Recent increases in dissolved-solids concentrations in this aquifer have been documented in some areas used for public supply, raising concerns as to the sources and causes of the higher concentrations and the long-term effects on groundwater quality.
Trace elements were present at high concentrations in 32% of the primary aquifers here, and at moderate concentrations in 17%. Of particular interest are aluminum, arsenic, vanadium, boron, fluoride, chromium, lead, and molybdenum.
The occurrence of solvents in the groundwater is not correlated with current overlying land use and human activities. Rather, the solvents are from legacy industrial uses, and it has taken decades for the groundwater to move to where it is now pumped.
Five trace elements with human-health concerns were detected at high concentrations: arsenic, boron, molybdenum, strontium, and vanadium. Chromium and fluoride were detected at moderate concentrations.
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.
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.