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<oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd">
  <dc:contributor>D. K. Solomon</dc:contributor>
  <dc:contributor>Niel Plummer</dc:contributor>
  <dc:contributor>E. Busenberg</dc:contributor>
  <dc:contributor>S.L. Schiff</dc:contributor>
  <dc:creator>P.G. Cook</dc:creator>
  <dc:date>1995</dc:date>
  <dc:description>&lt;p&gt;&lt;span&gt;Detailed depth profiles of Chlorofluorocarbons CFC-11(CFCl&lt;/span&gt;&lt;sub&gt;3&lt;/sub&gt;&lt;span&gt;(, CFC-12 (CF&lt;/span&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;span&gt;Cl&lt;/span&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;span&gt;) and CFC-113 (C&lt;/span&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;span&gt;F&lt;/span&gt;&lt;sub&gt;3&lt;/sub&gt;&lt;span&gt;Cl&lt;/span&gt;&lt;sub&gt;3&lt;/sub&gt;&lt;span&gt;) have been obtained from a well-characterized field site in central Ontario. Aquifer materials comprise predominantly silty sands, with a mean organic carbon content of 0.03%. Nearly one-dimensional flow exists at this site, and the vertical migration of a well-defined&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;/span&gt;&lt;sup&gt;3&lt;/sup&gt;&lt;span&gt;H peak has been tracked through time. Detailed vertical sampling has allowed CFC tracer velocities to be estimated to within 10%. Comparison with&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;/span&gt;&lt;sup&gt;3&lt;/sup&gt;&lt;span&gt;H profiles enables estimation of chlorofluorocarbon transport parameters. CFC-12 appears to be the most conservative of the CFCs measured. Sorption at this site is low (&lt;/span&gt;&lt;i&gt;K&lt;/i&gt;&lt;sub&gt;&lt;i&gt;d&lt;/i&gt;&lt;/sub&gt;&lt;span&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;&amp;lt; 0.03), and degradation does not appear to be important. CFC- 113 is retarded both with respect to CFC-12 and with respect to&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;/span&gt;&lt;sup&gt;3&lt;/sup&gt;&lt;span&gt;H (&lt;/span&gt;&lt;i&gt;K&lt;/i&gt;&lt;sub&gt;&lt;i&gt;d&lt;/i&gt;&lt;/sub&gt;&lt;span&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;= 0.09−0.14). CFC-11 appears to be degraded both in the highly organic unsaturated zone and below 3.5 m depth in the aquifer, where dissolved oxygen concentrations decrease to below 0.5 mg L&lt;/span&gt;&lt;sup&gt;−1&lt;/sup&gt;&lt;span&gt;. The half-life for CFC-11 degradation below 3.5 m depth is less than 2 years. While apparent CFC-12 ages match hydraulic ages to within 20% (up to 30 years), apparent CFC-11 and CFC-113 ages significantly overestimate hydraulic ages at our field site.&lt;/span&gt;&lt;/p&gt;</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.1029/94WR02528</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>American Geophysical Union</dc:publisher>
  <dc:title>Chlorofluorocarbons as tracers of groundwater transport processes in a shallow, silty sand aquifer</dc:title>
  <dc:type>article</dc:type>
</oai_dc:dc>