Abstract or Description:
Arizona well water is often contaminated with elevated concentrations of naturally occurring constituents that are a human health concern. This short fact sheet is the first in a two-part series about what naturally occurring contaminants may be found in your water supply well and includes a brief discussion on environmental pollutants that originate from land use activities. If you own a well in Arizona, you have the sole responsibility for checking to see if your drinking water is contaminated. Arizona state law does not require private well owners to test or treat their water for purity. The second part of this series outlines what to sample for and how to understand your analytical results.
The most common contaminants found in Arizona groundwater in concentrations above health-based drinking water standards are arsenic, fluoride, radioactive elements (responsible for gross alpha radiation), and nitrate. Nitrate contamination, although it can be natural, is usually due to either agricultural practices (excessive fertilizer use and/or poor irrigation practices), or failing septic systems that allow contaminated waters to drain into the aquifer. Naturally occurring groundwater contaminants are dependent on aquifer geology and are discussed below.
College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ)
Water Resources Research Center
University of Arizona Cooperative Extension Publication AZ1503