Centennial Honors College
Western Illinois University
Undergraduate Research Day 2014
Poster Presentation
Spatial and Temporal Relationships between Rainfall Events and Nutrient Levels
in the Spring Lake Watershed
Sara Stanford
Faculty Mentor: Steve Bennett
Geology
Management practices on land are directly related to groundwater quality. In particular,
agricultural nitrogen and phosphorus applications are implicated in elevated levels of
these nutrients in groundwater due to surface runoff. Moreover, the full effects of these
nutrients can take decades to emerge, even if the land use has shifted from agriculture
(Moorehouse, 2008).
Nitrates, if consumed above maximum contaminant level provided by the EPA, can
cause headache, dizziness, shortness of breath, and bluish of the skin in humans.
Heightened phosphorus levels can cause undesirable effects in streams, including algal
blooms, low dissolved oxygen, and the death of certain aquatic animals and fish.
Because it serves as a municipal water source, increased nutrients have long been a
concern throughout the Spring Lake watershed within McDonough County, Illinois.
Therefore, monitoring the levels of these nutrients in streams directly leading to the lake
should be a priority (Drinking Water Contaminants, 2013).
Eight sampling sites were selected in the fall of 2013 between September 11 and
October 13 in an effort to discern relationships between rainfall events and nutrient
levels in tributaries that lead to Spring Lake. The results show that there may be a
relationship between rainfall and nutrients at some sites while at others there is not a
strong correlation or not enough data to prove the relationship. This research has been
continued in the spring of 2014 with modifications from the fall. Previous results raised
questions about the effects of photosynthetic processes at site 2. Therefore, testing for
dissolved oxygen in spring 2014 aimed to relate nutrient levels and biologic activity.