Dr. Karen Wilson
Mill Brook is approximately 5 miles long and is an important migration route for Alewife during the spawning season. Mill Brook stretches from Highland Lake, Westbrook, Maine to the Presumpscot River in Portland, Maine and is surrounded by relatively well-protected forest land. However, chloride concentrations still rise from the upper end of the brook to the end: preliminary data, collected in the winter of 2017, showed an increase in mean chloride concentration from 37.28mg/L +/- 25.61mg/L at the start of Mill Brook to 51.25mg/L +/- 11.63 mg/L at the end of the brook. Chloride concentrations increase in the winter due to the use of road salts (NaCl) as a primary chemical for de-icing roads, parking lots, and sidewalks. The increase in salts in an aquatic system can negatively impact organisms that are adapted for freshwater habitats. The purpose of this study is to gather water quality indicators including specific conductance, salinity, dissolved oxygen, temperature, and chloride concentrations for each small tributary (e.g. streams, brooks, ditches, run off), as well as above and below each of those tributaries in Mill Brook. The goal is to help identify point sources of road salts which could be sources of other anthropogenic influences on the water quality for Mill Brook
Page, Devin, "Impact of road salts (NaCl) on winter water quality in Mill Brook, Westbrook, Maine" (2017). Thinking Matters Symposium Archive. 98.