In the Mid Atlantic area, there are several kinds of water wells that we encounter most every day. In general, the term “well” is defined as a man-made opening that penetrates the ground to some depth below the water table, generally to access or monitor ground water.
We wanted to describe and define the most common kinds of wells, and conditions that you might hear about relating to ground water wells. It’s important to know the type, and needs, of the wells that are critical to anyone owning or buying a house with a well!
This is a well that is drilled through layers of solid rock accessed an average distance of 30 – 50 feet below the ground surface. The rock is found beneath layers of soil, typically referred to as “overburden”. Water enters this type of well by flowing through a single, or series of “fracture(s)” in the rock, which occur and shift naturally, to provide a fresh water supply. The supply of water may be miles away from any specific well, and is likely supplied by ground water. And changes to the structure of these fractures is imperceptible, but constant.
These wells are lined with 6 inch “well casing”, the only visible part of the well which you see from above the ground surface. This well casing may be steel or plastic (PVC), both of which are suitable. The casing extends below the surface through the overburden, to depths where the driller feels solid rock is found. Beyond these depths, the rock serves as the containment for the well water supply, and the well casing is “grouted” to mitigate/eliminate “bacteriological contamination”.
Water is pumped from this hole to the home using a submersible (or above ground/jet) pump through a series of pipes, valves, adapters and regulators. Failure of any of these parts will stop the water supply from home faucets, tubs and other outlets.
Maintenance programs should include periodic testing and examination of the many electrical, plumbing and physical components (there are up to 40 parts) needed to deliver water from the well to the home. These tests should be performed by a licensed/insured well professional to sustain peak and reliable performance, and extend the life of the submersible pump. AS the source of the water may also change, homeowners should test the quality of the water for their family’s peace of mind.
“Sand (or alluvial) Well” (pronounced a-loov’-e-ul)
This is a well that is drilled into sand, mud or other substrata that is not a rock formation, to sufficient depths beyond the “overburden”. Ground water seeps, more than flows, into these wells, where the well driller must provide fully lined 6 inch “casing” and additional “screening” to provide a fresh water supply. The casing and water permeated substrata provides the containment for the well water supply, and this type of well is also “grouted” to mitigate “bacteriological contamination”.
Water is pumped to the home using the same equipment and techniques as a rock well described above. Failure of any of these parts will stop the water supply from home faucets, tubs and other outlets.
Alluvial wells require periodic “rehabilitation” as well as the maintenance described above to maintain reliable performance. Rehabilitation generally includes replacement of casing and screening components, and potentially limited re-drilling, to maximize the flow and accessibility of the ground water and preserve or extend the life of the pump.
“Hand Dug Wells”
this is an older type of well, that were literally dug by hand/shovel to fairly shallow depths. When adequate water supplies were found, the wells were typically lined with rocks, bricks or concrete to contain the well water supply, covered with additional wood or concrete, and pumped via pipe to the home using a small jet or auxiliary pump. Due to the shallow depths, they generally rely on natural springs or near-surface water to supply fresh water, but are subject to much higher rates of failure when the water tables drop, due to changes in surface water patterns. They are also much more subject to bacteriological contamination due to contaminants including animals, fertilizers and human contamination. Limited maintenance is possible on such wells, causing additional risks as to reliability.
While present in the Mid Atlantic Region, stick wells were not routinely used to obtain ground water for human consumption. The water supply is obtained by driving 2” semi-solid metal tubes (i.e. sticks) into the ground until water is forced to the surface. Small piping and pumps are used to transfer the water small distances for farm or family uses. Again, minimal maintenance is possible, and the frequency of finding these is very, very limited.
Homeowners (and real estate professionals) should be aware of the types of well they are dealing with, and be prepared to refer to experts about this key and expensive household system.
In general, WelGard® is not able to protect “Hand Dug” or “Stick Wells”; everyone should be wary about any wells not drilled, constructed and installed by contemporary methods, and to today’s standards. Problems with properly constructed wells cannot be predicted, and are therefore always disruptive and expensive; but problems and failures are a virtual certainty with hand dug and stick types of wells, and repairs generally require the installation of an complete new system, frequently costing tens of thousands of dollars.