BOTTOMS UP: A WATER QUALITY ANALYSIS ALONG THE FOURCHE BOTTOMS WETLANDS

The Fourche Creek Watershed covers 108,800 acres and provides a drain for about 73% of Little Rock’s water runoff. The wetlands in this area facilitate water purification, urban noise reduction, pollution controls, and can store up to one billion gallons of water during a storm event. Land use and development has continued in Central Arkansas creating more impervious surfaces, hence there are more areas in this region that do not allow for infiltration and therefore result in more runoff. In general, water quantity and quality in Fourche Creek may be impacted by the increase in impervious surfaces. During certain times of year, the wetlands revealed increases in cation concentrations (Ca, Na, Mg, and K) upstream of the wetlands, then decreases downstream from the wetlands. This research explores water quality in the Fourche Bottoms Wetlands through water column samples and leaching experiments conducted on sediment from the soil-water interface and suspended sediment in order to determine how contaminants decrease in the wetlands. Water and sediment samples were collected upstream, in, and downstream of the wetlands. Water samples were taken at each location and were filtered through a 0.45-micrometer filter. Several liters of unfiltered water were also collected at each location to measure total suspended sediments. Additionally, sediment was collected at each sampling location at the sediment water interface. The sediment was used in leaching experiments in a 10:1 ratio with deionized water and reacted for 20 hours. We compare the concentrations in surface water samples before and after the wetlands with that from the sediment leachate to determine what is deposited, or removed, from the system in the wetlands.