Bacteria Source Tracking on Little River in Westfield, MAMichael Fant, Jean-Baptiste Bangoret, and Tim Grady

AbstractThe quality of public waterways and drinking water can be directly linked to the overall health of an ecosystem as well as people living in the immediate area. E. coli is an indicator of a source of pollution so ensuring the water we drink or come into contact with isn’t full of contaminants, such as E. coli, is a crucial preventative measure for potential health risks. The goal of our project was to determine the levels and source of E. coli in the Little River, a tributary of the Westfield River in Westfield, MA. Previous studies have recorded that the Little River had high levels of E. coli. We sampled four sites along a 4.36 mile stretch of the Little River between Stanley Park and where the Little River enters the Westfield River, to see if any particular segment of the river was experiencing high levels of E. coli. Some sites experience high amounts of human and animal activity while other sites are relatively undisturbed. We collected a total of 37 samples over the course of four sampling days and analyzed these samples using approved EPA sampling techniques from Colilert, including appropriate quality control measures. In general we found relatively low levels of E. coli (MPN < 235), but we found excessively high levels of E. coli downstream of Crane Pond directly after the dam (MPN = 686.7 – 17,220). We hypothesized that the high levels were due to geese feces directly entering the water because large flocks of geese are known to congregate in and around the pond.

• Obtain water samples from all four locations, properly labeling each one and avoiding contamination of the sample.

• Bring samples to the laboratory and heat seal samples into Quanti-trays with various dilutions.

• Place the sample trays into incubator at 35 degrees Celsius for 22-24 hours.

• The next day place each sample under a black light and record how many individual cells of each size glow.

• Record the most probable number (MPN) by using the Table NPP IDEXX Quanti-tray*/2000.

Methods

Summary of Main Points1. Little River showed only high levels of E.coli near Crane Pond dam because of the presence of geese on the pond.2. Little River showed consistently low levels of E.Coli in areas where human/animal impacts weren’t present. 3. Water at the confluence of Little River and the Westfield River is generally safe for swimming.

ResultsOur results featured relatively low and safe MPN values for three of the four sampled locations. These three sample locations were not as impacted from human and animal activities as our fourth. The location with the highest MPN value recorded every sampling day was at Crane Pond Dam. The table below features an average MPN value of all our sampling days.

QuestionsOur study aimed to answer these questions concerning the Little River:1. Are there high levels of E. coli on Little River in Westfield, MA?2. If high levels are detected, can the source of the pollution be determined?

Future PlansIn the future, sampling above and downstream of the pond would help trace the source of E. coli and eliminate potential sources of pollutants. Seasonal sampling to monitor the impact the geese have on the water.

Sample Site Average MPN Value (per 100ml) of All Four Sampling Days

Stanley Park 116.32Granville Bridge 90.84

Crane Pond Dam 3261.85

Salvation Army 220.26

Acknowledgements

We would like to acknowledge Cindy Delpapa of the Department of Ecological Restoration and Dr. Tim Parshall for helping us begin our project and showing us how to interpret and analyze our results.

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Actual Value 17,220

*EPA recommended MPN < 235/100ml water