Apparent Chlorofluorocarbon Age of Ground Water of the Shallow Aquifer System,Naval Weapons Station Yorktown, Yorktown, Virginia

摘要

The purpose of this report is to describe the apparent chlorofluorocarbon (CFC)age of ground water in the shallow aquifer system on the Station and to refine the conceptualization of ground-water flow. The report presents the data and findings of a 1-year study that involved the use of environmental tracers and isotopes to estimate and confirm the apparent CFC age of ground water in the shallow aquifer system, (2) compares apparent CFC ages with water-quality field properties and calculated times of travel, and (3) presents estimates of ground-water recharge rates. Water samples were collected in March 1997 from 14 existing observation wells installed by the USGS (Brockman and others, 1997) and from 16 natural springs located throughout the Station. Apparent CFC ages, dissolved gas and stable isotope composition of ground water, and water-quality field properties were determined from the 30 ground-water samples.