Production of CFCs ceased in the United States as of January 1, 1996, under the Clean Air Act. M., ed., Regional Ground-water Quality: Van Nostrand Reinhold, p.
Other chemical dating tools Tritium (half-life 12.4 years) provides another useful tracer of young ground water. Tracing the young fraction in groundwater mixtures in the Upper Floridan aquifer near Valdosta, Georgia: Applied Geochemistry, v.
CFC-113 has been used primarily by the electronics industry in semiconductor chip manufacturing, in vapor degreasing and cold immersion cleaning of microelectronic components, and surface cleaning.
Probably better known to the public as Freon, CFCs are nontoxic, nonflammable and noncarcinogenic, but they contribute to ozone depletion. J., and Busenberg, Eurybiades 1994, Estimation and corroboration of shallow ground-water flow paths and travel times by environmental tracer and hydraulic analyses A case study near Locust Grove, Maryland: Water Resources Research, v.
The accuracy of the determined age depends in part on how perfectly the CFCs are transported with the water.
Chemical processes, such as microbial degradation and sorption during transit, can also affect the concentration of CFCs and other compounds used in dating.