Carbon Filter Update: Water Needs Less Treatment

So far, so good. Initial samples pulled from a well on the site show the installed in October is pulling natural materials out of the water supply, as hoped, according to the company's general manager.

David Condrey, the Water Company general manager, said the demand for chlorine to sanitize the water supply has dropped dramatically, as a result.

"The organic reduction we're seeing coming out of that one filter is great," Condrey said Tuesday.

The company installed the carbon filter, between two layers of sand, to pull natural materials from groundwater sources. A second carbon filter will be installed early in 2011. The purpose of the $280,000 filter is to reduce a contaminant that has been found in Milford Water in elevated levels for a year.

The carbon sandwich filter, approved by the state Department of Environmental Protection, is modeled after a system used by a town in Maine, which had also struggled with elevated levels of (TTHMs). The contaminant is formed in the disinfection process for public drinking water.

Since the carbon filter was installed, company officials have started flushing hydrants in Milford to move the filtered water through the system. About one-third of the town's hydrants have been flushed so far, Condrey said Tuesday.

The water passes through the filter, which pulls out the organic materials, and then moves through the treatment facility. Because of the carbon filter, Condrey said, "demand, if you will, for chlorine has dropped off significantly."

According to Condrey, an initial sample, taken Oct. 28 at the Water Company property, indicated the level of TTHMs had dropped to 75 parts per billion, below the 80 ppb allowed for public drinking water by the DEP.