The chart below will help you spot problems. The last five problems listed are not an immediate health concern, but they can make your water taste bad, may indicate problems, and could affect your well long term.
For more information on for more information on what human activities can polluteground water see:
- Drinking Water From Household Wells PDF (24pp, 1M)
EPA 816-K-02-003 January 2002
If you use a private laboratory to conduct the testing, nitrate and bacteria samples will typically cost between $10 and $20 to complete. Testing for other contaminants will be more expensive. For example, testing for pesticides or organic chemicals may cost from several hundred to several thousand dollars. Only use laboratories that are certified to do drinking water tests. To find a certified laboratory in your state, you can contact:
- A State Certification Officer to get a list of certified water testing labs in your state, or
- Your local health department may also test private well water for free. Phone numbers for your local, county, or state health department are available under the "health" or "government" listings in your phone book.
Most laboratories mail back the sample results within a week or two. If a contaminant is detected, the results will include the concentration found and an indication of whether this level exceeds a drinking water health standard.
- See the List of Drinking Water Contaminants and their Maximum Contaminant Levels (MCL) page for information on Drinking Water Contaminants.
If a standard is exceeded in your sample, retest the water supply immediately and contact your public health department for assistance. Some problems can be handled quickly. For example, high bacteria concentrations can sometimes be controlled by disinfecting a well. Filters or other on-site treatment processes may also remove some contaminants. Other problems may require a new source of water, or a new, deeper well. If serious problems persist, you may need to rely on bottled water until a new water source can be obtained.
You should test private water supplies annually for nitrates, coliform bacteria, total dissolved solids, and pH levels to detect contamination problems early. Test more frequently if a problem was found in earlier tests.
For more information, read Home Water Testing PDF (2pp, 564K)