Re: Explosive Compound Detection Methods

[Ted Henry <thenry@umaryland.edu>]

Thursday, August 6, 1998

Peter:

A few thoughts on your posting in follow-up to our previous conversations.
First, you mention that the CRREL method is a field screening test. I
would be surprised if this test has good limits of detection (field
screening tests are not normally very sensitive). In this light, it
would make sense to move to a more sensitive test, and from my
understanding 8330 is still considered a decent method. I would bet
that if one compares the LODs between the two, 8330 would win.

As mentioned, we moved to the CHPPM methods at APG to assess our
groundwater. It is believed that they are more definitive and more
sensitive, and although there are some lingering questions I would like to
get answers to, we did recently detect RDX at 0.045 ppb, which is a factor
of 10 lower than the EPA-Region III risk-based concentration of 0.61 ppb.

As far as why the contractors suggested 8330, it is likley they did not
even know about the CHPPM methods. I did some work in California and the
Navy's contractor did not know about them either.

As far as throwing out the data, this seems premature. I agree that it
should not be discarded as "false positives", and I would stand firm on
demanding some clear logic before doing so. I would suggest conducting
additional sampling with an agreed upon method and then look at all the
data (old and new) and assess the presence/absence and concentrations of
contamination then.

Lastly, it I would make sure that with whatever method is selected, it
is capable of detecting all the expected degradion products as well. Is
the field screening method capable?

As you recieve more information, please post info on 8515?

Also for anyone else, there is a draft EPA method known as 8095. Does
anyone know its status (I tried to track this mehtod down months ago
through EPA personnel and had no luck)?

Keep up the good work.

Peace

Ted

***************************************************************

Theodore (Ted) J. Henry, MS

*Managing Director,
Community Health Assessment & Public Participation (CHAPP) Center

*Technical Advisor,
Aberdeen Proving Ground Superfund Citizens Coalition(APGSCC)

737 West Lombard Street, Room 540
Baltimore, Maryland 21201-1041
(410) 706-1767 - phone
(410) 706-6203 - fax
thenry@umaryland.edu
***************************************************************