Tuesday, August 21, 2012

Confusion, detection limits and action levels

It is time for me to "go" there.
The article was in the Advocate (Stamford newspaper) talking about detection limits and how tests before 2011 were not any good because they could not "see" trace amounts of the pesticides everyone was worrying about.
The reality is many tests done by several labs were reported down to a detection limit that was as sensitive as it could be, many were not and it depended on the lab.
A discussion on this can be found at the following link.
It is confusing.
There were labs which were simply taking peoples money and doing a test which was only a screening test.
There were other labs who would not report down to the detection limits.
Now tho, there is another wrinkle - the state lab will no longer report anything below the current action level.
There maybe politics involved since they used to do this.
If the DEEP uses the state lab, then one could expect to see some where around 5% of the wells with reportable amounts of pesticides in CT.
In Stamford, we have been looking for any amount detectable and that level runs about 19%.
This of course will mean that "pesticides" are a "Stamford" problem and not a big deal.
I have seen (and have some of them in my possession) reports from other towns with pesticides in wells that are both above the action levels and below.
These wells are not necessarily near Stamford.
Is 19 or 29% unacceptable and 5% is?
Those are questions people need to ask and it does get confusing.
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