According to the EPA, actual events of drinking water contamination are rare, and typically do not occur at levels likely to pose health concerns. However, drinking water can get contaminated from naturally occurring sources in the environment or through human and animal activities. Some possible sources of contamination include:
We recommend using a lab that has been certified by the MD Department of the Environment (MDE) to provide water tests. MDE updates their list of certified labs every year. We have pulled out the labs that provide testing services for private well owners, which you can access here.
If you have not tested your water in several years, we recommend getting a comprehensive test that includes the following contaminants (* indicates those that are of particular concern for pregnant women, infants, and young children):
You should also contact your county well permitting office to check for any additional contaminants that may be of local concern. Once you have tested your water, you should continue with routine tests as follows.
ANNUALLY: Test for coliform bacteria and nitrates.
EVERY 3 YEARS: Test for pH, Total Dissolved Solids, and Sulfates.
You should also test your water if:
Once you receive your results from a water testing laboratory, simply enter those values into the appropiate boxes on the website below to get an interpretation of your results.
Contaminant | What is it? | Health Effects |
Total coliform bacteria | Bacteria that occurs naturally in the environment and is found on the soil and in vegetation; General indicator of water quality | May cause gastrointestinal distress |
Nitrate | Compound found in fertilizer and manure | Shortness of breath; Blue baby syndrome in infants under 6 months; Health risk to pregnant women |
pH | An indicator of the water’s alkalinity or acidity | Not harmful to human health, but depending on the value, the pH can affect the taste and feel of the water, damage plumbing, and potentially leach dangerous metals from pipes and fittings |
Lead | Metal that acidic groundwater can leach out of plumbing, pipe materials, or lead solder or brass fittings and components | Irreversible damage to the brain, kidneys, nervous system, and blood cells; Irreversible developmental effects make children, babies, and fetuses most susceptible to lead poisoning |
Copper | Metal that acidic groundwater can leach out of plumbing, pipe materials, or lead solder or brass fittings and components | Gastrointestinal distress; Liver or kidney damage |
Sulfates | Naturally occurring compound in groundwater | High levels may cause diarrhea, causing dehydration that is especially detrimental to infants and young animals |
Total Dissolved Solids | General indicator of water quality; Measures dissolved impurities | Not harmful to health; High levels may affect the water’s taste |