RE: NATIONAL PRIMARY DRINKING WATER REGULATIONS

[sbrightwell@shepmill.com (Shane Brightwell)]

Jean-Michel,

There are no current maximum contaminant levels (MCLs) for U in the US.
Standards proposed in 1991 of 20 ug/l were withdrawn, but it is likely that
a similar U standard will be proposed by 2001.

Proposed Rn standards for public domestic water supplies were published in
Federal Register on November 2, 1999.  Proposed MCL for Rn is 300 pCi/l;
Alternate MCL (AMCL) of 4000 pCi/l has been proposed to be implemented in
conjunction with an approved multimedia mitigation program for reduction of
Rn in indoor air.  You can e-mail Dr. Janet A. Johnson
(jjohnson@shepmill.com) or go to the EPA website if you want more
information.  Hope this helps.


Reg's,

Shane Brightwell

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