What is a Well?

AWater well well is a hole drilled into the ground to access water contained in an aquifer. A pipe and a pump are used to pull water out of the ground, and a screen filters out unwanted particles that could clog the pipe.

Wells come in different shapes and sizes, depending on the type of material the well is drilled into and how much water is being pumped out.

More than 42 million people in the United States use individual or private wells to supply water for their families.

Three Basic Types of Wells

  • Bored or shallow wells: are usually bored into an unconfined water source, generally found at depths of 100 feet or less.

  • Consolidated or rock wells: are drilled into a formation consisting entirely of a natural rock formation that contains no soil and does not collapse. Their average depth is about 250 feet.

  • Unconsolidated or sand wells: are drilled into a formation consisting of soil, sand, gravel or clay material that collapses upon itself.

Are You a Private Well Owner?

For more information on Water Wells, visit Wellowner.org, your one-stop resource for information relating to private water well systems.

Well Construction

All private well construction is based on establishing the right location for the well, sizing the system correctly and choosing the proper construction techniques. Only professional water well contractors should install wells. They are familiar with the hydrology in an area and all local codes and regulations. Proper well construction is key to operating and maintaining a well.

A well is composed of many components. The most important materials used include:

  • Casing: is used to maintain an open access in the earth while not allowing any entrance or leakage into the well from the surrounding formations. The most popular materials used for casing are black steel, galvanized steel, PVC pipe and concrete pipe.

  • Grout: is a sealant that is used to fill in the spaces around the outside of the well. It protects the well against the intrusion of contaminants. A grout mixture can be made of cement, bentonite, or concrete (each used separately).

  • Screen: keeps sand and gravel out of the well while allowing groundwater and water from formations to enter into the well. Screen is available in many materials, the most popular being stainless steel and slotted PVC pipe. Screen is used when wells are drilled into unconsolidated materials.

  • Gravel pack: is placed around the outside of the screen to prevent sand from entering the well or clogging the screen and to stabilize the well assembly.

Well Contamination

Well testingA well can easily be contaminated if it is not properly constructed or if toxic materials are released into the well. Toxic material spilled or dumped near a well can leach into the aquifer and contaminate the groundwater drawn from that well. Contaminated wells used for drinking water are especially dangerous. Wells can be tested to see what chemicals, pathogens and other contaminants may be in the well and if they are present in dangerous quantities.

Things You Can Do to Protect Your Groundwater and Water Well

Well owners should create a well maintenance log to keep track of the well’s history, construction details, water testing results, inspections, and regular maintenance and repairs.

Well owners should inspect the wellhead several times a year to check the conditions of the well covering, casing, and cap.

The well should also be inspected every 10 years or so by a qualified well driller or pump installer.

Well owners should ensure that the water from the well is tested annually for bacteria and nitrates (at a minimum); more often if there has been a change in the taste, color, or smell of the water.

Items like household chemicals, paint and motor oil should be kept away from a well. These items should be properly disposed of by taking them to a recycling center or household hazardous waste collection site.

In addition, try to avoid mixing, applying, and using any chemicals or other potential pollutants within 100 feet of your well.

Well owners should conduct a regular visual check for potential contaminants at or near the well, checking for items such as septic tanks/systems, chemical storage, machinery maintenance areas, waste/trash piles, sewers, underground or above ground storage tanks, animals pens or feedlots, and manure storage areas. If at all possible, move these items away from the well.

Also known as a sanitary seal, the well cap can keep potential contaminants out of a well and groundwater. The cap should be kept clear of leaves, mulch, dirt, snow and other materials. It should also be inspected regularly to ensure it’s undamaged and has no cracks.

The wellhead is the structure built over the well to protect and contain its parts, and it’s important that this first line of defense against contamination is kept intact.

Be careful when working or mowing around the well. Heavy equipment can easily damage the well. Avoid piling snow, leaves, or any other materials around or near the well where they can carry contaminants into the well and down into groundwater.

Ensure that the top of the well sits at least one foot above the ground, and the slope is angled away from the well to ensure proper drainage when landscaping or siting a new well.

Water conservation can help well owners keep their drinking water supply safe and plentiful, as well as saving money. By using more efficient fixtures, such as low-flow showerheads and toilets, and high-efficiency clothes washers and dishwashers, well owners can cut their water use by upwards of 30% (according to the Water Systems Council).

Well owners with wells that produce less than 5-10 gallons per minute should be cautious of how much demand is placed on their wells, making water conservation even more important.

Small changes such as repairing leaky faucets and toilets, turning off the tap while brushing teeth or shaving, taking shorter showers, running full loads in the clothes washer and dishwasher, and watering outdoor plants only when necessary can add up to big water savings.

Why should I test my well water?

Testing your private well’s water quality on a regular basis is an important part of maintaining a safe and reliable source. The test results allow you to properly address the specific problems of a water supply. This will help ensure that the water source is being properly protected from potential contamination, and that appropriate treatment is selected and operating properly.

It is important to test the suitability of your water quality for its intended use, whether it be livestock watering, chemical spraying, or drinking water. This will assist you in making informed decisions about your water and how you use it.

Regular testing is important to:

  • Identify existing problems
  • Ensure water is suitable for the intended use, especially if used for drinking by humans and animals
  • Track changes over time
  • Determine the effectiveness of a treatment system

The quality of a water source may change over time, even suddenly. Changes can go unnoticed as the water may look, smell, and taste the same.

Is my water safe to drink?

The only way to tell if your drinking water is safe is by having it tested at a certified laboratory. Harmful bacteria, parasites, and viruses are invisible to the naked eye, so water which looks and tastes good may not necessarily be safe to drink. These microbes can exist in surface and groundwater supplies, and can cause immediate sickness in humans if not properly treated.

Certain chemical contaminants that are sometimes found in a water source can cause long term health problems that take years to develop. Frequent water testing will identify unsafe water and ensure that the treatment system is treating the water to a satisfactory level.

What tests should I have done?

Useful tests are available to help determine the health and safety of a water supply, and the performance of a water treatment system. Your local health department can assist in selecting tests important for assessing your drinking water.

Useful tests are available to help determine the health and safety of a water supply, and the performance of a water treatment system. Your local health department can assist in selecting tests important for assessing your drinking water.

  • Basic water potability. Include tests for coliform bacteria, nitrates, pH, sodium, chloride, fluoride, sulphate, iron, manganese, total dissolved solids, and hardness.
  • Coliform bacteria. Indicate the presence of microorganisms in the water that are potentially harmful to human health.
  • Nitrate. A common contaminant found mainly in groundwater. High nitrate concentrations can be particularly dangerous for babies under six months, since nitrate interferes with the ability of blood to carry oxygen.
  • Ions. Ions such as sodium, chloride, sulphate, iron, and manganese can impart objectionable taste or odor to water.
  • Sulfate. Excessive amounts of sulfate can have a laxative effect or cause gastrointestinal irritation.
  • Fluoride. Fluoride is an essential micro-nutrient, but excessive amounts can cause dental problems.
  • Total dissolved solids. Represent the amount of inorganic substances (i.e. sodium, chloride, sulphate) that are dissolved in the water. High total dissolved solids (TDS) can reduce the palatability of water.
  • Additional testing. Other tests may be appropriate if a particular contaminant is suspected in the water. For instance, groundwater sources are sometimes tested for arsenic, selenium, and uranium. Both surface and groundwater sources may also be tested for pesticide contamination.

How often should I test my well water?

Private well water should be tested a minimum of once per year. Drinking water supplies obtained from shallow wells and surface water sources should be tested more frequently (i.e. seasonally), as they are more susceptible to contamination.

It is important to test your drinking water at the tap and at the source. Testing both will help you determine if your treatment system is performing correctly, and if the quality of your source water has changed.

Where can I get my well water tested?

Contact your local or state Health and Human Services Department. They will be able to refer you to a certified laboratory in your area. In addition, many communities offer free screenings, called “Test Your Well” events. You may also use the Find a Contractor feature on Wellowner.org to find well water testing companies in your area.

The Ultimate Water Well Resource

For more information on Water Wells, visit Wellowner.org, your one-stop resource for information relating to private water well systems.