An Examination of Possible Hydrodynamic
Controls on Bacteria Concentrations in the Runnins River
Sc. B degree of Environmental Sciences
May 2004
The Runnins River located in Seekonk, MA exhibits high fecal coliform bacteria counts throughout the year, with concentrations spiking in the summer months. Bacteria concentrations are subject to variations in temperature, land development and rainfall-driven increases in streamflow (Hunter and Colin, 1992; Curriero et al., 2001). In the absence of a streamflow record from the Runnins River I use the area-normalized continuous flow record from the Ten-Mile River to predict the continuous flow pattern on the Runnins River. Comparison of continuous discharge with bacteria concentrations yields a poor relationship. Furthermore the observation of elevated concentrations during dry weather suggests a contributing source other than storm-driven runoff from upstream. When examining samples that were taken when the Runnins River was tidally influenced, the median concentration was significantly higher than those samples unaffected by the tide. Concluding that the source of impairment is from the tidal disturbance and mobilization of bacteria-harboring phragmites wrack.