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Access a legend for the map below
Source of Map: Water Resources Inventory of CT, Part 4, Southwestern Coastal River Basins,
by the U. S. Geological Survey and the CT Department of Environmental Protection, 1970.

THIS IS AN EARLY (1970) GENERALIZED MAP OF ESTIMATED AQUIFER BOUNDARIES ONLY;
COMPARE IT TO LATER DATE USGS SURFICIAL MATERIALS MAP

HISTORIC BASE LINE DATA: 1980 HVCEO
REPORT ON BRANCHVILLE AQUIFER
This aquifer was to small to be evaluated by the 1980 study.

EXCERPT ON THE BRANCHVILLE AQUIFER
FROM A 1995 RIDGEFIELD PZC CONSULTANT’S STUDY
This aquifer is beneath a portion of the Norwalk River watershed, at the southeastern corner of the Town. There is one USGS test hole drilled in the aquifer and two well completion reports are on file at the Ridgefield Health Department.

The logs indicate that the stratified drift is up to 50 feet thick and is composed of discontinuous, poorly-sorted sand and gravel. The DEP and USGS have mapped the aquifer as containing coarse-grained stratified drift. The USGS mapped the maximum saturated thickness as greater than 10 feet but less than 30 feet. The areal extent of the aquifer is about 0.2 square miles.

The grain size of the aquifer material appears to be sufficiently coarse to allow the development of wells, but the thickness of the aquifer would be a limiting factor.

No analyses of water samples for organic compounds has been performed. Analysis for major ionic constituents are on file at the Health Department. LBG's search of the DEP's records revealed a past leak in an underground storage tank containing fuel oil, for which no record of remediation was found and a 750-gallon gasoline spill which was washed down by the fire department.

The aquifer is beneath a commercial area along Route 7 which, by nature, presents a higher risk of contamination, but one that can be controlled with best management practices.

The 7 day, 10 year low flow was estimated between 0.6 and 0.9 million gallons per day and the average low flow was estimated to be about 2.0 million gallons per day from a total watershed area of about 11.0 square miles.