A variety of student projects have dealt with various aspects of Strawberry Creek water quality. Historical low flow water quality data is summarized in Table 8, whereas wet weather sampling data is presented in Table 9.
The pH measured in past studies of the creek was similar to that observed during this baseline study. The pH generally decreased in the downstream reaches of the creek. No trends in pH were discernable in the historical wet weather sampling data.
Conductivity was high during past storm sampling and increased downstream. Turbidity was high in the South Fork in past low flow studies and increased about 200% during storm pericxis. Turbidity during dry weather was higher in the past than the concentrations observed in this study. Likewise, suspended solids levels were moderately high in the South Fork in past studies and were elevated over the concentrations observed during this study.
Historical dissolved oxygen concentrations in Strawberry Creek were more than adequate to support aquatic life and increased during storm pericxis, possibly because of turbulence. The dissolved oxygen concentrations in the past were lower than those measured during this study.
Nutrient levels measured in past studies were high in the creek. Total phosphate concentrations generally increased further downstream. Both phosphate and nitrate concentrations were higher in the South Fork than in the North Fork. Historical ammonia levels in the creek were high before reaching the central campus, but only moderate to slightly elevated on campus. Ammonia concentrations during wet weather were very high and increased further downstream.
Total coliform bacteria concentrations were high in the central campus reaches in past studies, and tended to increase downstream. Bacteria concentrations in the North Fork and in the Main Branch above Oxford Street increased about tenfold over low flow levels during past storm sampling.
Grab samples taken during past wet weather sampling showed low lead concentrations, elevated cadmium concentrations, and very high mercury concentrations in the South Fork and in the Main Branch of the creek above Oxford Street Concentrations of all these heavy metals increased slightly in the downstream reaches of Strawberry Creek.