Well Testing procedures

As an acreage owner I have had to haul water from the city and it is not fun, not by a long shot. Well water supply and water quality are more critical then you may think.  In order to help my clients reduce their risks of a well failure and to help them understand what it will take to have good water quality,  I recommend the following inspection procedures. The well is usually one of two main types, bored well with a 5” casing or a dug culvert style well of about 36” diameter. I will cover sand points in another article. The dug well is usually not as deep with about 100’ being about the deepest you find in this area. My current bored well is 468’ deep. Wells and well water can be hit and miss so its important to understand as much as possible about the well.

I recommend every well have a flow test.  Its one thing to have nice clean water but it is another thing when that water runs out after you run a bath and the dish washer. Yes this can happen. When buying a property it is very important to know how much water you can reliably count on from the well. A flow test can be done that will give you that information.  Without getting too detailed I will try to explain how this works. First of all the well is drawn down using two garden hoses running out onto the ground. The well will drop depending upon how fast the water runs back into the well. If the water drops really fast the test will end and a recovery portion of the test will begin. Usually the well draw down will last for about 1-2 hours (providing the well can sustain itself). Then a test is done to see how fast the well recovers back to the original position without using any water.  The test includes a tool which sends a pulse down to the surface of the water and back to the tool. The test results show the draw down and recovery rate and from that the flow rate can be estimated.

Generally speaking a flow rate of 1 – 2 gallons per minute would be considered on the low side for an average family. Over three gallons is usually enough water to sustain a family of four. Most bored wells in our area are about 120- 240’ and have limited amount of stored water. This means that a well that is known to produce two gallons per minute will run dry in a few hours if the garden hose which is can expel about five gallons per minute is left on. On the other hand a dug well may have storage of several hundred gallons of water and the same well production may not dry up for twenty hours of running the same garden hose.

The best thing about having a flow test is to learn the limitations of the well. If the well is a low producer you may decide to have a holding tank in the basement that provides a buffer when necessary. This approach requires times and floats but works very well.  I hoped to cover more on this topic but I will continue this in the next column as I believe it is critical information for the home owner.

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