Re: Dating of Water via Tritium Determination

[Holloway3@aol.com]

In a message dated 97-01-24 00:30:50 EST, you write:

<< Dating of water cannot be done "by enrichment of tritium in the sample".
 Only for achieving a very low lower limit of detection enrichment is used.
 The dating is a process which does not only involve measurement of tritium,
 but has to consider many other hydrogeological parameters. I am sure, that
 quite a lot of competent laboratories exist in the USA, not only a few.
 There are other means to date ground waters, like C-14 concentration,
 O-18/O-16 ratios, even noble gases like Kr-85.
  >>

 I would hope that you and I would not add to the tremendous amount of
clutter on this mailing list, so I will be brief.  The question originally
asked about the number of laboratories in the United States that use tritium
in attempts to date ground water.  The fact is that there are not many,
contrary to your opinion.  For about 15 years, I supervised tritium
enrichment at the Environmental Protection Agency in Las Vegas, so I have
personal knowledge and contacts with the laboratories involved. You say quite
correctly that the use of tritium does not provide dates in a strict sense
and that the use of other parameters is also useful.  However, my point was
that doing an enrichment of the water sample is necessary to get any useful
information from the tritium content  because the detection limit for tritium
without enrichment is too high to provide any useful information.  Whether
this "information" should be called dating is open to question, but all other
methods of "dating" ground water have disadvantages that are quite as
serious..  Incidentally, several of the laboratories involved in tritium
enrichment conduct a Quality Assurance program on tritium enrichment, so we
know with good accuracy the number of laboratories who are interested in this
matter.  I would not presume to estimate the number of labs in Europe doing
tritium enrichment because that is not my backyard.