The Dawson Aquifer is the most vulnerable to contamination from both natural and human sources. However, this does not imply that the other aquifers below it are not also susceptible to contamination. Generally, the deeper one goes into the Denver Basin, the less contamination is encountered. Most samples taken from the Dawson Aquifer exhibit oxic conditions and show detections of uranium (U), selenium (Se), and arsenic (As). Additionally, several pesticide compounds were also found in these samples. 

About 60 percent of contaminated bedrock aquifer samples are located within three urban development areas with high groundwater usage. This may suggest that water use practices are contributing to the vulnerability of these aquifers. Additional samples taken from the Dawson Aquifer exhibited similar characteristics. Due to their poor quality, many of these contaminated waters are affected by redox processes. The redox conditions in the bedrock aquifers may also attenuate concentrations of dissolved oxygen (DO), nitrate (NO3), uranium (U), selenium (Se), arsenic (As), and some volatile organic compounds (VOCs).

Groundwater samples from the Dawson aquifer were primarily identified as mixed-age, suggesting a combination of recent recharge with older groundwater. Tritium was found at levels typical of young groundwater in over half of the sampled locations. While some samples indicated they could be thousands of years old, the presence of oxygen suggests that mixing between older water and recent recharge likely occurred in the Dawson aquifer. (Musgrove et al., 2005)