When asked to describe a well, most city folks will conjure up an image of a hole in the ground, surrounded by a stonewall and covered with a roof, with a bucket and pulley arrangement to bring up the water. To the rural homeowner who does not have the luxury of a connection to the city water department, a well is as important as the walls and roof of the house.

In order to understand how a well works, you have to understand how water gets in the ground in the first place. The technical term for well water is ground water. This is simply rain water and snow melt that has seeped into the ground instead of running off into a stream or a river. This water will continue to flow downward until it hits bedrock and it cannot go any farther. The earth above the bedrock will become saturated and the top of this saturated layer is called the water table. A well is a shaft that cuts through the soil all the way down to the water table in order to access ground water.

There are three types of wells – dug wells, driven wells and drilled wells. A dug well is simply a hole in the ground sunk in the water table either by hand or using some kind of excavating machine like a backhoe. The sides of these wells are usually lined with cement tile, to keep them from collapsing, and have a gravel base.

A driven well is a series of pipes with a point on the end that is forced into the ground to the water table. By their nature both dug and driven wells are not very deep and are more susceptible to drought and contamination than drilled wells. However they work quite well on property where the ground is soft and where the water table is close to the surface.

Homeowners should be aware that there are some potential problems with wells. The first is the possibility that the well may dry up. This could happen because of a lack of rainfall, other wells tapping into the same aquifer or the homeowner simply outpacing the water supply.

Most modern wells are drilled wells, sometimes called artesian wells, which require a fairly complicated and expensive drill rig. These rigs can reach sources of water over 1,000 feet in the ground by using a large auger bit in soft soil or, in the case of rock, either a rotary drill bit or percussion bits which smash their way through. The upper portion of the well shaft is lined with a casing to prevent it from collapsing and to keep the well from becoming contaminated with surface runoff. Because these wells are so deep, they often require a pump to be placed directly in the well to draw the water to the surface.

Sometimes the water in the well is under enough pressure to force it partially or all the way up the well shaft.

The main advantage of having a well is that once it is drilled and hooked up to a house, the water is basically free. And because well water is naturally filtered by the surrounding soil, there is often no need to treat it with chemicals like chlorine. As a result, many people find well water tastes better then municipal water. Sometimes having a well on the property can increase the value of the house.

Homeowners should be aware that there are some potential problems with wells. The first is the possibility that the well may dry up. This could happen because of a lack of rainfall, other wells tapping into the same aquifer or the homeowner simply outpacing the water supply. According to the Empire State Well Drillers Association, the amount of water needed for a family of four is between 300-600 gallons per day. But you need to take into account peak demand times and extra guests, so the amount of water flowing into a well should be around four to ten gallons per minute.

Another possible problem with wells is contamination of the water… These substances could be something relatively minor like iron or sulfur or something much more serious like radon, arsenic or uranium.

Another possible problem with wells is contamination of the water. Water is an excellent solvent. As it moves through layers of rock and soil, it will dissolve minerals and other substances that will not necessarily be filtered out by the time the water reaches the well. These substances could be something relatively minor like iron or sulfur or something much more serious like radon, arsenic or uranium.

Bacteria or other surface pollutants can also get into the well if surface water runoff flows into it. Make sure that the well has a secure cover (or cap) on it, the casing isn’t cracked and it protrudes at least a foot above ground. Also check that the well is situated well away from any external source of pollution. In general, a well should be at least 200 feet away from any garbage dump, landfill or cesspool; 50 feet away from any septic tank, tile sewer, leach field or foundation drain; 20 feet away from roads and 10 feet away from sewer lines.

If a homeowner suspects that his well has become contaminated with bacteria, the first thing to do is to get the water tested. This can be done with either a simple home water quality test kit or by contacting the appropriate state or county water quality agency. Twin State homeowners can call The New Hampshire Department of Environmental Services at (603) 271-3503 or contact the Vermont Department of Health Laboratory at (802) 863-7335.

If the well is contaminated with bacteria, clean up is relatively easy. A simple solution of chlorine bleach at approximately 1 gallon of bleach for every 100 gallons of water is circulated through the well and then flushed out through the house’s water pipes. This will kill any bacteria in the system and after a few days the water should be safe to drink, but be sure to test the water first just to be safe. Check with local water officials for specific instructions before trying to disinfect a well.