Well Water - Background Information

Many houses now use private wells as a source of drinking water. There are generally 3 types of private drinking wells used today:

Dug

Dug - These wells are made by digging a hole in the ground and then casing the hole with a strong material to prevent collapse, such as stone, brick or tile. Dug wells are not very deep, usually ranging from 10 to 30 feet, this short depth means these types of wells are most at risk from contamination. There are a number of features your dug well should have to minimise the chances of contamination:

The well should be cased with a strong, watertight material.
The opening of the well should be covered by a concrete lid that is positioned about a foot off the ground.
Build a mound around the opening of the well so that surface water runs away from the well.
Try and have your water pump leading to a separate building rather than right next to the well.

Driven

Driven - These types of wells are usually deeper than dug wells, ranging from 30 to 50 feet in depth. This is still reasonably shallow and therefore a driven well has quite a high risk of contamination. There are a number of features your driven well should have to ensure proper construction and minimise the chances of contamination:

2 to 3 inch diameter metal pipes should be driven into the ground, with a screen at the end of the pipe. This helps to drive the pipe through sand and gravel so that the water that enters the well is filtered from particulate contaminants.
Put the pump on top of the well or in a separate building.M
The well and pit should be capped with the same kind of tile used for dug wells.
Follow the same instructions as given for dug wells.

Drilled

Drilled – Drilled wells are the deepest form of well and range from 100 to 400 feet in depth. They intersect bedrock cracks containing ground water and this enables a water supply to be given. There are a number of features your driven well should have to minimise the chances of contamination:

A metal or plastic casing should extend into the bedrock to prevent any shallow ground water from entering the well.
Your well pump should be installed and serviced regularly by a professional.
Try and adopt a pitless adapter design for your well, this seals the point where the water leaves the well and enters your home.
You can increase the yield of your well and maybe improve its quality by a process called hydrofracting. This is where water or air is pumped into the well at high pressure, opening up existing fractures and creating new ones.

You should make sure your well is properly constructed and maintained through regular water testing. They should be well located so that rainwater flows away from it and possible nearby contaminants can be properly monitored so that chances of contamination are kept to a minimum.