Richard Pasquill, Manitoba Water Services Board, Brandon
Of all the practices utilized in mechanizing water system, the well pit can create more problems than anything else. It not only is the major source of well contamination, but can by very dangerous to work in or around. A well pit is basically a large cribbing placed over the top 6-8 feet of the well with smaller well casing (4-10 inches) being cut off just above its base. The waterline(s) coming out of the well are then connected to the water line(s) distributing the water around the yard. Because the water lines are located below the frost level, this provides a frost free connection to the well.The major problem with well pits is their susceptibility to pollution. In many cases, runoff water seeps into the pits and down the well. As the well pit becomes older, mice and rodents invade the area with some falling down the well. While a well seal can be installed on the top of the well casing to prevent these occurrences from happening, the owner will invariably render the seal ineffective the first time the pump or well has to be serviced. The pit can also become a death trap when the well is serviced by a well driller or if the water contains certain gases. Because most gasses such as methane or hydrogen sulphide are heavier than air, they tend to father in the bottom of the well waiting for some unsuspecting person to enter.
The best method of hooking up the waterlines to a well is with the use of a pitless adaptor. These are devices which allow the waterlines inside the well to be connected to the waterlines outside the well using a series of ³O² rings and seals. To install the unity, the top portion of the well casing is first exposed and the outer portion of the pitless unit is attached to the well casing. A water tight seal between the well casing and the pitless unit prevents any water or liquid on the outside of the casing from getting into the well and causing future pollution problems. The water distribution lines outside the well are then connected to the pitless unity with a 90º threaded elbow to allow for ground settlement around the well. The excavation is then filled in and the inner well pipes connected to the inner portion of the pitless unit. This inner portion is then lowered down the well and connected in place with ³O² rings. These ³O² rings provide a water and pressure tight seal between the inner pipes and the outer pipes being joined. If the waterlines inside the well have to be removed, the well cap is taken off and the lines simply pulled upward. The area around the well should always be built up with clay to allow for settling and prevent water from coming within 10 feet of the well. This will prevent contaminants from seeping down into the water formation around the well crib or casing and causing a pollution problem.
The use of a pitless unit in hooking up to a well is by far the most desirable and safest method and in most cases is cheaper than installing a well pit. Certain pitless units can also be used to connect the waterlines in large diameter (36-48 inch) wells.
| For further information on this (403)427-2727 Sask Water (306)694-3900 Manitoba Water Services Board (204)726-6076 PFRA (Sask) (306)780-6350 |
