Roughly one out of every eight American households - mostly in rural and semi-rural areas - are served by private domestic water wells. These wells tap ground-water sources that can be as shallow as 20 feet (in areas with a high water table), or as deep as hundreds and even thousands of feet (in semi-arid regions and deserts).

All wells begin life as test wells, drilled into the earth to see whether the water there is pure enough, and the well can deliver a sufficient quantity of water over time to serve the home. Once past these hurdles, the well receives well casing to prevent collapse and a submersible pump placed at the bottom of the well. A flexible pipe connects the pump to the home’s plumbing.

Problem is, well water that looks clean isn’t necessarily pure. Many forms of water contamination are odorless and tasteless. Water that’s completely transparent and has no off-taste or aftertaste can still carry harmful organisms and chemicals.

The only way to be certain about water quality is to have a sample analyzed by a reputable laboratory. If your well water has never been tested, or if you’ve recently acquired property served by a well, experts generally recommend getting a comprehensive analysis of water quality to establish a “baseline” – benchmarks allowing for assessment of future improvements in, or degradation of, the water supply.

A water analysis is also the first step in deciding whether filtration is necessary, and if so, what kinds of systems would be most appropriate for your particular situation.

With a baseline established, simpler tests can be conducted periodically thereafter to check for common contaminants. Basic parameters include:

•  Bacterial count, to gauge possible contamination from septic systems or animal waste
•  Assessment of pH, to check acidity or alkalinity
•  Color and turbidity, or clearness, depending on region
•  Tests for the presence of nitrites or nitrates, also depending on region

Water analysis costs vary depending on location, company and comprehensiveness. The price can range from less than $20 to more than $100. Many licensed well contractors also perform water testing. Contractors that don’t offer this service should be able to refer you to a reputable laboratory.

Water analysis may give peace of mind if the results are good, but many other factors influence the quality of well water. Following is a list of things you can do:

•  Know the location of your wellhead, and inspect the physical condition of visible components. The top of the well should have a tight-fitting cap or seal. Call a certified professional if the cap is broken or missing, if the well casing is cracked or broken, or if standing water forms a pond around the wellhead.
•  The well casing should extend above ground to prevent introduction of surface contaminants. Never cut the casing below the surface.
•  Never mix or use fertilizers, pesticides, fuel, oil, de-greasers or other pollutants near the well.
•  Don’t dispose chemical waste of any kind in a dry well, septic system or anywhere on the ground. Hazardous wastes like these can travel through soils and render well water permanently undrinkable.
•  Have the septic system pumped and inspected for proper function by a certified professional as often as recommended by officials from your local health department.
•  Hire a certified well contractor any time the well needs service. It takes proper training and specialized equipment to prevent water-source contamination – and to avoid personal injury, since this work can be hazardous.