Composition of Creek Sediment Through Farmland - Kittitas County

We measured the elemental composition of sediment at the heads compared to the mouths of six different streams in Kittitas County, Washington. Sediment composition can determine the effects of large-scale agricultural fertilization and the health of stream ecosystems as they flow through farmland. We collected two sediment samples from each of the six creeks we selected in Kittitas County, and determined the elemental composition of the samples. We analyzed the samples using Central Washington University’s ICP-OES which provided results in which most streams had high amounts of specific elements, including: aluminum, calcium, iron, and potassium. Our measurements showed the opposite of our hypothesis; streams contain higher concentrations of elements at the tops of creeks versus the bottoms, with a few exceptions that may have resulted from errors in the procedure. Further research could be conducted to determine why higher concentrations of elements are found at the tops of creeks, and whether this is the case in other counties as well