Figure 1. Well pit.
Figure 2. Pitless adaptor types.
Installation
Pitless adaptors are installed 2 to 3 m (6 - 10 ft) below ground level for protection from frost. The ground is excavated around the well casing to this depth, and a hole is made in the well casing. The discharge fitting is installed and attached to the water pipe. The discharge fitting is either clamped, bolted or welded onto the casing.
Some pitless adaptors come as a 2 to 3 m (6 - 10 ft) pre-assembled unit. These adaptors are attached to the well casing that has been cut off below frost level.
Once the discharge fitting is installed and the water pipe to the pressure tnak is in place, the excavation is backfilled with clay material, then compacted. The well casing should extend a minimum of 20 cm (8 in) above the ground surface. A ventilated cap is installed for sanitary protection. The ground surface around the well should be mounded and sloped to drain water away from it.
Removal
Pitless adaptors provide convenient access to the submersible pump for maintenance or repair. Removal of the submersible pump depends on the type of pitless adaptor installed. Generally, a metal cable on spring-type adaptors can be pulled to disengage the spring locking mechanism, and the pump is pulled out using the galvanized extension pipe. Slotted-type adaptors can be pulled directly using the galvanized extension pipe, while some models require loosening of the adaptor assembly with a screwdriver or wrench before pulling out the pump.
For further information, contact any of the Agricultural Water Specialists with Alberta Agriculture and Food at the following locations:
Lethbridge (403) 381-5846
Red Deer (403) 340-5324
Edmonton (780) 422-5000
http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/agdex1135