Pesticide variance revisited

For the past 4 years, i have remarked that i have not seen significant variance in pesticide levels in wells where it was found.
At first because the variance in one well in two test done 11 years apart was insignificant.
Then there were 8 wells in which in DEEP was taking samples quarterly and except in 2 cases of potential collector error (one was acknowledged and the other not)  there was not a significant variance.
In the last part of sample collection this year 2 wells were repeated - one had nothing showing in 2009 and had dieldren over the action level in 2012.  The other had trace levels a few years ago and not only was dieldren over the action level, there was chlordane showing up as well.
One occurrence is an anomaly, twice something to be concerned about.
I believe that the Health Department will recommend continued testing.