Ground-water availability and water quality at Southbury and Woodbury, Connecticut

Water-Resources Investigations Report 84-4221




Increases in population and commercial and industrial development during the past 20 years have increased the demand for water in the Towns of Southbury and Woodbury, Connecticut. The stratified-drift aquifer, underlying much of the Pomperaug River valley, is the most practical source for additional large supplies. The yield of the aquifer was evaluated with a two-dimensional, digital flow model. The model was constructed with hydrologic data from previous studies, and test boring logs , seismic profiles, water-level measurements, and other information collected during the present study. Simulations made with the calibrated model indicate that, with no pumpage, groundwater levels in the aquifer will fall about 4.6 ft below average during low-recharge (least-favorable) periods, and rise about 0.6 ft above average during high-recharge (most-favorable) periods. Simulated withdrawals from 10 wells indicate that from 5.0 to 8.8 million gallons/day are available as total recharge rates range from 21.4 to 36.1 inches/year. If these pumpages were consumed or exported from the basin, estimated average flow reductions of the Pomperaug River would range from 7.7 to 12.9 cu ft/sec. The quality of the water from the stratified-drift aquifer is generally excellent in most areas and meets State drinking-water standards. Chemical analyses of groundwater from 11 wells in the Middle Quarter area of Woodbury indicate that organohalide compounds are present. A maximum trichloroethane concentration of 260 micrograms/L has been reported and groundwater in the area is presently being monitored for organohalides. The water meets standards established by the State. Surface water samples collected at 7 sites in the study area meet the Connecticut drinking water standards for all constituents except coliform bacteria. Complete conventional treatment of surface water from some wells will be required to meet State drinking water standards relative to coliforms. (USGS)

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USGS Numbered Series
Ground-water availability and water quality at Southbury and Woodbury, Connecticut
Series title:
Water-Resources Investigations Report
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U.S. Geological Survey,
viii, 105 p. :ill., maps ;28 cm.