Water sample tests will identify the amount of dissolved minerals in your well water. Well water usually has calcium, iron and manganese with levels ranging from soft (less than 17.1 parts per million-ppm) to very hard (over 180 ppm). Tests look for waterborne pathogens (disease-carrying organisms), often from leaking septic systems or run-off from livestock. They also look for dangerous chemical or metal contaminants, such as pesticides, fertilizers and metals, including lead, boron and mercury.
Most well water requires softening to reduce the levels of dissolved minerals in the water. Commercial water softeners are divided into salt and non-salt systems. Each replaces mineral ions with salt (or a salt replacement) ions, making the water taste better and stain less.
Water softening systems are a cost-effective way to treat all of the well water coming into your house. Many users add carbon-based filters at the kitchen sink to further filter the water, making it taste and smell more palatable for drinking and cooking.
If testing reveals biological contaminants, your water must be disinfected. Depending on the contaminants discovered, treatment options include Ultra-Violet (UV) exposure, which passes water through a chamber where UV light kills the pathogens. Other options include diffusing a disinfectant gas, such as chlorine or ozone--as used in most municipal treatment systems--into the water.
The level and type of biological contaminant will determine your best disinfectant treatment
For dangerous levels of chemical (including dangerous metals) contaminants, the best treatment options will usually be ultra-filtration systems, up to Reverse Osmosis (RO) filtration.
Again, your specific contaminant will determine the amount of filtration required. The rule of thumb is the greater the amount of filtration required--how small are the items to be filtered out of the water--the greater the cost or the lower the volume processed.
Regardless of the treatment system you choose and regardless of your local testing requirements, test your system after it is installed.
If you have treatment for biological or chemical contaminants, test your system no less than twice each year to ensure your treatment is keeping your drinking water safe.