The other day we received an inquiry from Jason who asked if we knew of ways to test for the presence of farming chemicals in well water… because he had fears about once-allowed (and now banned) chemicals used in the farming industry seeping into his shallow well.
All of you who stop by the Water Testing Blog on a semi-regular basis already know we believe owners of private wells need to keep an eye on the quality of their well water. A point we have not discussed, until today, deals with whether owners of shallow wells have more to worry about than owners of deep wells.
Difference between shallow and deep wells?
This subject gets a little murky… depending on who you talk to:
- Some folks say a shallow well has a total depth of 100 feet or less and deep wells have a depth of 100 feet or more.
- Other folks say a shallow well has a smaller top diameter (less than 2″) and that a deep well has a larger top diameter (greater than 2″).
- And finally, we have also read that some people tell the difference between a deep well and a shallow well by the volume and flow rate of the water produced by the well. Note: We read of this way of classifying a well as shallow or deep a lot less frequently than the first two methods.
So as you can see, regarding the matter of defining what constitutes a deep well versus a shallow well, some disagreement exists. We wish the disagreement stopped here, but it does not.
Is a deep well better than a shallow well?
The waters get REAL murky on this topic… unfortunately.
Quite honestly, it seems as though the matter of which well type will work best for a residence depends largely on a few key factors:
- Placement and depth of your water table. How far underground must a well go before it reaches the water table and what sort of depth does the accessible water table have?
- Flow rate and volume of water required by a residence. As a general rule, residences with an expectation of requiring more water at a faster rate should normally consider having a deep well installed — but clever well contractors looking to help homeowners keep costs down may also tie several shallow wells together at the head with specialized topside pumping equipment.
- Intended use for the water once pumped to the surface. Dependent upon location, of course, deep wells may have a tendency to draw water containing a higher desired amount of minerals that could eventually cause problems with plumbing (i.e. in the form of clogs and fixture staining). Additionally, we have read that not all plant-life can tolerate high mineral content on its leaves and other exposed surfaces.
Our advice? Contact a certified and experienced well water consultant in your area to go over your expected water needs before deciding on a shallow or deep well for your property.
What about farming chemicals and shallow wells?
Some feel that the difference in the amount of rock and other filtering media between where a shallow well draws its water and a deep well pulls its water makes the quality of deep well water better than the quality of shallow well water.
This does sound like a very plausible hypothesis and also like one that we, too, can agree with. Therefore, and of course all well water situations may very, we would say that if Jason fears the presence of now banned herbicides and pesticides in his water, then he should certainly have his water tested by a qualified, certified water testing laboratory that can perform testing for compounds like VOC’s and obviously herbicides & pesticides.
We suggest trying to use a local laboratory since their experience working with the local water supply(ies) typically gives them a leg up when it comes to knowing what contaminants to look for in a region’s water.
If availability of a lab or cost make using a local water testing lab not an option, then companies like National Testing Laboratories offer mail-in water testing packages that include as many as 20 ‘commonly found’ 20 pesticides, herbicides and PCB’s (including Atrazine, Simazine and Alachlor) as well as up to 47 VOC’s (including Benzene, Methyl Tert Butyl Ether (MTBE) and Trichloroethene (TCE)).
As of 4/8/2013 you can find nine different test kits from National Testing Laboratories available in our Water Test Kit Store: http://shop.watertestingblog.com.