The Westfield River has been closely monitored over the last 7 years for salinity content; river waters are classified as sodium chloride waters with Calcium and Sodium being the two most abundant cations. To establish a natural baseline we examined variations of these two cations at three specific locations; upstream location WFR-5 representing rural areas, Mid Stream samples representing the urban zones, and downstream location WSR-1 representing the lowermost reaches of the Westfield River. Uppermost samples from WFR-5 have an average Calcium and Sodium concentration of 6.32 ppm and 9.41ppm respectively. Differences in Sodium and Calcium concentrations between the uppermost reaches and Mid Stream samples are not significantly different; however, they are significantly different to the lowermost reaches, WSR-1 which yielded concentrations of 9.9 ppm and 24.43 ppm for calcium and sodium respectively. Fluctuations in concentrations over time within each section of the river can be attributed to variations in flow rate. However, these fluctuations do not explain the increase in salinity downstream. We attribute the increase of downstream salinity to contribution from tributaries such as Great Brook.