Pesticides - the myth of home owners use

For a while, it looked like it was true.
I was seeing a pattern, most, not all, wells that showed pesticides in the tests, were close to a homes foundation.  That was a pattern.  Then the health department did its "50 well survey" and we ended up with only 35 tests (that was because out of 130+ people contact, only 35 responded in a "we want our water tested") and we also checked out other information.  Also, when some one would call to ask about submitting results, i would ask how close to the home the well was. 
It turns out that most wells in Stamford were drilled or placed within 30 feet of the foundation.
This meant that all my earlier thoughts were null and void.  If a majority of wells are close to a home's foundation, you can not make a coorelation to the quanity testing positve to pesticides with the closeness of a well to a home.
Of course this is not everything that made me change my view...I had one well sampled where i knew there was pesticide application down, i had even found a bottle of chlordane in a storage shed there in the 80's.  The well is an old one, dug in the early 1900's (1905 in think) and is only 50' deep with a well pit.  It is just outside the back door.  Knowing all of this, i expected it to come back positive - nada - zip, no trace down to 0.005 ug/L.
Of course on the other side of the coin, there are a number of deep wells drilled in the 1990's, that have come back positive.
This would lead me to say it was more the way we disposed of those chemicals, rather than the way we used them.
So the garnering of information goes on...