| Abstract: | Officials in Oswego County, in north-central New York, have been concerned about potential contamination of community wells. Many of these wells are completed in unconfined glacial sand-and-gravel aquifers, although some are finished in till or in the underlying fractured and jointed bedrock of Late Ordovician and Early Silurian ages. Local shallow ground-water flow is affected by the orientation and hydraulic characteristics of the local topography and surficial sediments, whereas deeper regional flow is toward Lake Ontario. Concentrations of chlorofluorocarbons and tritium in water samples from 28 wells in the county were measured in 1999 for ground-water-age dating; results yield recharge dates ranging from about 1955 to 1994.
The presence of water older than about 15 years in the sand-and-gravel aquifers differs from previous concepts of recharge sources and ground-water movement that were based on numerical modeling of ground-water flow. Young ground water (1 to 5 years old) probably represents recharge from recent precipitation and seepage from streams, whereas the oldest ground water (more than 40 years old) probably is derived from the fractured bedrock that underlies the glacial sediments or has moved along long flow paths in unconsolidated deposits, or through poorly permeable material. Some sand-and-gravel aquifers in Oswego County contain mixtures of old and young water. Wellhead-protection efforts need to focus on protection of the quality of young water in the sand-and-gravel aquifers because young water is more likely to be contaminated than old water. |
| Genre: | USGS Numbered Series |
| ProdID: | 50411 |
| Citation Author: | Komor, Stephen C. |
| Citation Contributing Office: | USGS New York Water Science Center |
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| Citation Edition: | - |
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| Citation Language: | ENGLISH |
| Citation Larger Work Title: | |
| Citation LatN: | 0450000 |
| Citation LatS: | 0400000 |
| Citation LonE: | -0720000 |
| Citation LonW: | -0800000 |
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| Citation No Pagination: | |
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| Citation Online Only Flag: | |
| Citation Phsyical Description: | iv, 16 p. |
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| Citation Public Comments: | Prepared in cooperation with the Oswego County Department of Health |
| Citation Publisher: | Geological Survey (U.S.) |
| Citation Series: | Open-File Report |
| Citation Series Code: | OFR |
| Citation Series Number: | 2001-232 |
| Citation Search Results Text: | Ground-Water Age Dating in Community Wells in Oswego County, New York; 2001; OFR; 2001-232; Komor, Stephen C. |
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| Citation Year: | 2001 |
| Type: | citation/reference |
| Text: | Ground-Water Age Dating in Community Wells in Oswego County, New York; 2001; OFR; 2001-232; Komor, Stephen C. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/usgs_thumb.jpg |
| URL (INDEX PAGE): | http://ny.water.usgs.gov/pubs/of/of01232/ |
| Date Other: | Sat, 1 Feb 2003 00:00 -0600 |
| Publisher: | Geological Survey (U.S.) |
