Municipal drinking water being applied to a neighborhood lawn. The geochemical character of Missouri River-derived drinking water is distinct from local surface water and groundwater in St. Louis. In particular, drinking water in the St. Louis area features high concentrations of boron. Thus, we use boron as a tracer of municipal water inputs to streams and groundwater. We have found that municipal water use, like lawn irrigation and wastewater release, contributes substantial non-point source loads of boron and other chemicals to urban streams.
Rock salt being applied to a neighborhood street. Road salt application elevates sodium and chloride concentrations in streams and groundwaters, but transport and retention of these contaminants remains poorly understood.
Plastic debris along the Ohio River. We observed these large plastics while sampling for microplastics (which occur due to the breakdown of larger plastics or use of personal care products).
Many human activities in urban and agricultural areas have the potential to modify or contaminate proximal surface water and groundwater resources. The Hydrology and Geochemistry Lab relies on tracers like stable isotopes, major ions, and trace elements to identify anthropogenic sources of water or chemicals that modify natural waters.
Some of our research projects include:
1. Identifying municipal water (both drinking water and wastewater) inputs into surface waters and shallow groundwater.
2. Examining the extent of road salt contamination in streams and groundwaters.
3. Quantifying microplastic (i.e., plastic debris <5 mm in diameter) loads to the Mississippi River watershed.
4. Understanding nutrient dynamics in lakes impacted by agriculture.
Group member, Andrew Shaughnessy, collects sediment samples from the bottom of Carlyle Lake in Illinois. Carlyle Lake is an impoundment of the Kaskaskia River that is highly impacted by agricultural land use and fertilizer runoff. We are studying how the chemistry of lakebed sediments control nutrients levels at this lake and others and what implications sediment-water interactions have for triggering algal blooms. We work closely with the National Great Rivers Research and Education Center (NGRREC; http://www.ngrrec.org/) for this research.