I've heard horror stories about contaminants seeping into residential well water from area industrial sites, gas stations, and the like. To protect my family from this potential hazard, how often would you suggest that I test my well water, and where can I obtain the materials necessary for doing so?
Unfortunately, it is all too possible for residential water from private or community wells to be contaminated with toxic organic chemicals, or heavy metals, at concentrations that represent long-term health risks. For example, many toxic organic chemicals can cause significant health problems above a concentration of 10 parts per billion (PPB), but until such a contaminant reaches, say, 100 PPB, it may remain completely tasteless and odorless. Therefore, detecting organic and heavy-metal contaminants in the appropriate concentration ranges can generally be done only by using sophisticated instruments in a chemical laboratory. Worse yet, a complete battery of tests by a commercial lab may be expensive. Before you give up in despair or spend your hard-earned greenbacks, follow these suggestions:
First, find the source of your drinking water. If you have a private well, mark its exact location on a map of the surrounding area. Likewise, if you drink water supplied by a public utility, find the location of that well or reservoir and designate it on a map. Then walk or drive around all the land within a five-mile radius of the well, checking for any abandoned or operating industrial sites, hazardous waste dumps, or municipal garbage pits. If your search turns up nothing, you can breathe a partial sigh of relief, because it's likely — though not guaranteed — that your well will not be contaminated by any sources of pollution beyond that radius.
If, however, you still want to have your water analyzed, call your state capital's Environmental Protection Agency office or talk with a chemist at a local university. Tell these professionals the nature of your concerns and the results of your walking survey, and state precisely that you want your water analyzed for trace organic chemicals and heavy metals but not for bacteria, viruses, pH, or hardness. If these folks can't do the job, ask them for the names of at least three commercial laboratories that could possibly provide such a service.
Next, check with the county health department. Even if the people there don't have the sophisticated equipment necessary to analyze your water, they, too, should be able to recommend some reputable commercial labs that do.
Then, if you have no choice but to go the “commercial” route, contact several laboratories to learn about their services, prices, methods and response time. Stress exactly what it is you're seeking, and check to be sure that the facility has a gas chromatograph (GC), to measure the trace organic compounds, and an atomic absorption spectrophotometer (AA), to measure the heavy metals. Also inquire whether the laboratory will do any preliminary GC scans in a “semi-quantitative” fashion, as this option can save you money if it's readily apparent that your water is uncontaminated. Finally, find out how and when to take the water sample. You simply cannot fill an old pickle jar with tap water and expect to get valid results!
There's no rule of thumb as to how often you should have your well water tested, it will depend on your setting and the amount of money you want to spend. Regardless of your testing schedule, though, keep an eye on activities within the “zone of influence” around your well to safeguard that water supply in the future. An ounce of prevention is truly worth a ton of cure!
— David Burmaster, a consultant on surface- and ground-water quality and hazardouswaste management