Storm Sampling
The ISCO automatic wastewater samplers are programmed to collect stream water during storm events using increasing stage height as a trigger to initiate sampling. Samples are then collected throughout the duration of the storm event to produce an estimate of water quality for the entire storm. Stormwater samples are collected after each storm and taken to an environmental laboratory for analysis.
In 2004, we were able to obtain composite samples that spanned entire storm events (using the ISCO samplers) for five (5) and seven (7) storms at the upper and lower stations, respectively. Samples could not be collected from the upper station during some storms due to no flow conditions. No samples could be collected during the late fall of 2004 due to a lack of storm events of sufficient size to result in elevated flow conditions. Sampling recommenced in April 2005, and to date we have collected five (5) and eight (8) rounds of additional storm event composite samples from the upper and lower sites, respectively. As was the case in 2004, samples from the upper station could not be collected during storm events owing to no flow conditions. One-way ANOVA analyses were performed on the data to explore differences in the mean concentrations between the upper and lower stations. The results of these analyses, and descriptive statistics, are presented in the following figure.
