Springtune

Jeff Green | May 24, 2007

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Spring tune up for your drinking water well

by Mary Jane Conboy, PhD.

Well water should be tested for bacteria at least once a year and after any repairs to the well system have been performed. It is also important to assess the water quality if you suspect contamination due to a change in color or odor of the water, or due to continuing gastrointestinal illness.

Early spring is a great time to test your well water and inspect your well. Another good time to test your well water is the day after a heavy rainfall. The melting snow or running water transports a lot of material from the surface deep into the soil. This can cause material from the soil surface to move into your drinking water source. Testing your water at times when contamination is likely will provide you with the most accurate assessment of how safe your drinking water is.

You should check the condition of your well at least once a year. Use a strong flashlight and take a good look at every part of the lining, water surface, pipes and well head. When you inspect your well you are looking for:

Any rodents or debris that may have fallen into the well over the year. Clean out debris using bucket on long string and then disinfect system.

Cracks or evidence that the well is not water-tight. You should have a water-tight seal on your well that extends at least 10 feet deep. This helps ensure that surface water filters through at least 10 feet of soil before it can enter the well. Repair any cracks or loose concrete

Top of the well - All wells should extend at least 16 inches above- ground or above the highest known water level in areas subject to flooding. Well tops are not generally watertight, so they should not be buried or located below ground in frost pits. This permits direct entry of surface water, or spills.

Abandoned wells - Unused, deteriorated wells allow pollutants to enter the groundwater, which can lead to contamination of active wells nearby. In addition, abandoned wells are a safety hazard, particularly for children and animals. For these reasons, unused wells should be properly plugged.

Preventing bacteria from entering your well water.

Treating contaminated well water is one way of ensuring your water is safe to drink. For a more long-term solution, the source of bacteria should be identified and where possible eliminated. If your water contains high levels of bacteria and nitrate, it is not wise to invest a lot of money in water treatment systems before addressing the structure of your well. Treatment systems treat the water and eliminate the contaminants from your drinking water, but these systems do not fix the problem, which is bacteria and nitrate entering your water supply. If possible you should try to eliminate the source of contaminants entering the water or seek another source of water for your drinking water supply. This could mean drilling a new well, repairing your current well or simply buying bottled water for drinking water.

Locating the source of contamination - This process can be quite simple or may involve detailed testing using tracers to map the flow of water on your property.

Consider these factors when determining the most likely source of bacteria entering your well water:

1. How many times has your well tested positive for bacteria? If your well has had many tests that exceeded drinking water standards for bacteria, it is likely that there is a constant source of bacteria entering the well. If your well is properly sealed and there is no debris in your well, the source may be entering from the groundwater, not the top of the well.

2. Assess the slope of your property or local area. Water tends to flow downhill and groundwater tables tend to follow the slope of the land. On some properties the house may be built up on a local elevation, small hills immediately surrounding a house or barn may reflect disturbances from the construction of the house and may not reflect the slope of your groundwater table.

3. Where is your septic system or livestock yard (manure pit, etc) in relation to your well? All contaminants should be located downhill from your well water. This is true even if tile drains are present to direct most of the water in a different direction.

For more information on how to care for your well, visit www.wellwise.ca, where you can order a copy of “Well Wise: A comprehensive consumer’s guide for private

water wells”.