Gross Beta Drinking Water Standard Requirements -Reply

[TOOHEYR@ORAU.GOV]

Meg:

A somewhat more intelligible summary of the monitoring requirements is
given in a paper by Lappenbusch & Cothern, Health Phys. 48 (5) 535-551
(1985).  Note that this refers to the still current, and not the proposed
drinking water standards.  If gross beta is >50 pCi/L, you must do
radionuclide analysis, either by beta- or gamma-spectrometry, or both. 
The standards for beta-emitters (man-made) are dosimetric (4 mrem/yr)
as opposed to concentrations, although MCL's are published or can be
derived.  Since this is a groundwater supply and your gross alpha is >
15 pCi/L, I would pursue the alpha side first, analyzing for U and Rn, then
Ra; some of your beta may well be from the naturally occurring chains. 
Of course, if you are "near a nuclear facility" you should contact them to
get an idea of what to look for.

Dick Toohey
Program Director, Radiation Internal Dose Information Center
423-576-3448
TooheyR@ORAU.GOV