How to Contaminate Your Own Well

by Ken Williamson, Agricultural Engineering, Technologist, Alberta Agriculture, Red Deer, Alberta

Imagine waking up in the morning, starting to brush your teeth, and discovering that barn yard runoff has made its way into your well. This scenario is not all that funny, but it does happen on some farms and acreages every year. The biggest culprit in these problems is the well pit. In years past, it was common practice to cut the well casing off about 8 feet below ground and construct a cribbed pit at the site. The purpose of this pit was to provide a freeze-proof location for the pump and pressure tank, and often a cold storage for vegetables.

A well pit is one of those things that sounds like a good idea at the time, but often ends up causing more problems than it solves.

• pits often become funnels that allow surface water into the well
• seasonal high water tables often flood pits and contaminate wells
• pits are damp locations and provide a poor environment for electrical equipment
• water on the pit floor can increase the electrical shock hazard
• pits are usually too small to allow proper service of equipment
• rotten vegetables make poor pit fellows
• pits make good traps for mice and skunks (usually lethal)
• pits can be dangerous for children
• well pit explosions are common in areas where water contains methane gas

There are several ways to deal with pit problems

• don't use a pit in the first place, use a pitless adaptor. Pitless adaptors make economical, sanitary, frost-free, connections from the pump to the buried water line
• if you have a pit, extend the well casing above the ground level, install a pitless adaptor, and backfill the pit with clay
• if the pit is absolutely necessary, be sure to install an automatic sump pump in the pit and be sure that your well casing has a properly installed sanitary well seal
• don't use the well pit for storing vegetables

If seepage or surface water gets into your well, pump it continuously for a day or two, then shock chlorinate the well. A couple of weeks after the well has been shock chlorinated, the well should be tested for bacteria. These tests can usually be arranged through your local health unit.