THE EFFECTS OF FLOWRATE ON WATER QUALITY: A COMPARATIVE STUDY OF BACTERIAL AND MAJOR METAL CONCENTRATIONS DURING HIGH AND LOW FLOW CONDITIONS IN THE WESTFIELD RIVER

Students enrolled in the General Science program at Westfield State University are encouraged to participate in active research work during their senior year. Herein we present the results of a research project investigating water quality parameters of natural surface river waters. While comprehensive studies of natural water systems include analyses of major cations, anions as well as minor and trace elements the work presented only disseminates results on bacterial content and major cations. Westfield State University is a liberal arts institution and the instruments available for comprehensive studies are limited; for example, the institution has an Atomic Absorption instrument but not an ICPMS nor a HPLC which would permit analyses of minor and trace elements as well as anions. Nonetheless, the data obtained from the available analyses (some major cations and bacterial content) yields a compelling and interesting story that not only enriches the state of knowledge of the Westfield River but also serves as a viable research experience for our senior undergraduate students.

River waters were collected and analyzed for bacterial content and naturally occurring metals (Ca, K, and Na) during high (> 1500 cfs) and low (< 50 cfs) flow conditions. As expected, bacterial counts were elevated during high flow conditions and it is interpreted as a response to run-off. Metal concentrations remain within expected values found in natural surface waters and their response to flow is opposite to that of bacterial content ^(1,8,11). That is, for any particular site, lower metal concentrations were observed during high flow periods; this is attributed to dilution. In addition, samples from the East Branch and northern main stem show lower concentrations than those observed downstream near the river’s mouth in both high and low flow conditions. This is interpreted as either increased water-rock interaction along the flowpath or addition of waters with higher metal concentrations from tributaries feeding into the river between the northern main stem and the river’s mouth. Furthermore, metal ratios remain unchanged regardless of flow condition and location. For this reason we conclude that metal sources are naturally occurring and not a result of anthropogenic run-off e.g., road salts.