FARMINGTON — Portions of the Sandy River around Farmington may have a reddish tint for short periods starting Wednesday as a dye tracing study is done this week to track the rate of flow and dispersion of water on the river from Farmington to New Sharon.

Scientists and engineers from the national Environmental Protection Agency’s New England Regional Laboratory along with staff from the Maine Department of Environmental Protection will conduct the study starting Wednesday and continuing through Friday.

Rhodamine WT dye will be released Wednesday afternoon in the Sandy River in the vicinity of the Route 43 bridge in Farmington. As a result of the dye release,  portions of the river in the Farmington area may turn reddish in color for a brief time. The dye is not harmful to people or the ecosystem.

“The color won’t last long but can be seen,” said Rob Mohlar from the state DEP.

The EPA staff will also conduct flow measurements at four stations in Wilson Stream from the outlet of Wilson Lake to the mouth near the Sandy River in Farmington as part of the project.

The EPA has been trying to do the study for about four years. It was looking for low flow conditions, Mohlar said. Wet summers prevented the testing but now the need for the study has changed, he added.

Originally the study was planned because the water quality was impaired. They wanted to study the why and how and what needed to be done, he said.

The location of treated water discharged from Farmington’s treatment plant, the outfall, was on a bank and in a non-moving area but the town did relocate the outfall further out in a more rapid moving part of the river, he said.

The water quality now is within the limits but the study will still be done to collect data, he said.

They’ll put dye in and watch different points downstream to see how it disperses and mixes into the stream, he said.

The study could be postponed again if the area receives any heavy showers that could raise the water levels. A low flow of water is needed.

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