How Is Our Water Quality?
The CT Dept. of Energy and Environmental Protection (DEEP) rates the water quality in the state’s rivers to determine which water is safe to use for drinking and for recreation, such as for swimming and fishing. To set standards for water quality, the CT DEEP considers several factors including the levels of contaminants present in water samples. The main stem of the Norwalk River is a Class B river, which means the water is not used as drinking water, but is generally safe for recreational use. Two tributaries, the Comstock Brook and the Silvermine River are used for drinking water.
Based upon the water quality data collected by HarborWatch, which monitors the Norwalk River, the water quality in the Norwalk River Watershed is moderately impaired. In other words, it doesn’t always meet the Class B standards set by the state. Water Quality Reports from HarborWatch and CT DEEP, available here , indicate that bacteria levels frequently exceed the state’s water quality criterion for Class B waters at a number of sites along the Norwalk River. Most sites meet the dissolved oxygen level criterion, and conductivity levels are consistently higher in the upper reaches of the watershed than in the lower watershed.
The Norwalk River watershed contains two areas of severe contamination. There is one superfund site, the field fenced off along Main Avenue in Norwalk which drains to The Kellogg-Deering Well Field site in Norwalk near the river. Construction was completed in 1996 on a system that treats contaminated ground water on site and makes it available as drinking water in the First Taxing District. The watershed also contains one brownfield, the Gilbert and Bennet Wire Mill in Redding, which has not been remediated. The Norwalk River passes through the site.
Where Does the Pollution Come From? In 2009, the CT Department of Energy and Environmental Protection completed a Stressor Identification Study for the Norwalk River which shows the sources of contamination and how they affect aquatic life (everything that lives in the river).