Pathogen Source Identification and Characterization by Designed Sampling

Nine sampling events, in dry and wet weather, were executed in a combined sewer overflow impacted stretch of the lower Passaic River at Paterson, New Jersey. Multiple water quality parameters were measured at 18 sites which included in-stream sites and representative locations at combined sewer outfalls, stormwater outfalls, and tributaries. The data was analyzed using t-tests and simple linear regression. Analysis of dry weather samples indicated all tributaries in the study area act to increase in-stream bacteria concentrations. Bacteria concentrations were higher at 6 AM than at 10 AM or 1 PM, possibly due to increased bacteria decay due to sunlight and temperature or unknown sources. Total suspended solids concentration was highly correlated with bacteria concentration at shallow sites, suggesting the possibility of sediment resuspension as a possible source at these sites. DO is a significant predictor variable at all sites except the upstream boundary suggesting sewage is a contributor.