Very often, well water can often be contaminated with potential pollutants which may impact human health adversely, or in some cases just make the water taste bad. It’s important to have your well water tested regularly to ensure it is safe for consumption and use. This can be done through a professional water testing service or by purchasing at-home testing kits.

You should test your well water for contaminants regularly and take steps to reduce the risk of contamination. Here we will discuss some of the most common potential contaminants in well water and their effects on human health.
Potential Well Water Contaminants
- Bacteria and viruses
- Arsenic
- Chemicals
- Hydrogen Sulfide
- Nitrates
- PFAS
- MTBE
- Radionuclides
- Radon
- Uranium
- Trihalomethanes
Bacteria and viruses
Bacteria are microscopic, single-celled organisms that can live and function completely on their own. They have the ability to ingest food and create energy from it. Although most bacteria discovered in water aren’t harmful, some of them can cause disease.
These microorganisms can cause gastrointestinal illness and, in extreme cases, be life-threatening. Testing for bacteria and viruses should be done regularly, especially if there have been recent changes to the well or nearby septic systems.
Bacteria play an important role in groundwater, as they change organic carbon, forms of common elements, and minerals such as iron, manganese, sulfur, phosphorus, nitrogen, and oxygen.
Arsenic
Arsenic is a naturally occurring element found in rocks and soil. It can dissolve into groundwater through natural processes and also be released into the environment through human activities such as mining and burning coal.
Arsenic can have serious health impacts, causing skin damage and cancer. Long-term exposure to low levels of arsenic can also lead to heart disease and diabetes.
It’s important to test for arsenic regularly, as there is no easy way to remove it from water. If high levels are found, a professional treatment system may be necessary to make the water safe for consumption and use.
Chemicals
Pesticides, industrial chemicals, and cleaning products can all potentially seep into well water and contaminate it. These chemicals can have a range of health impacts, including respiratory problems, cancer, and reproductive issues.
If you use chemicals around your well or live near agricultural or industrial areas, it’s important to test for these pollutants regularly. In the case of chemical contamination, switching to a different water source may be necessary.
Hydrogen Sulfide
Hydrogen sulfide is a colorless gas with a strong odor, often described as “rotten eggs”. It can occur naturally in groundwater, but may also be released through industrial processes such as oil and gas drilling.
Although hydrogen sulfide generally does not present health concerns at the levels typically found in drinking water at home, it can be unpleasant – particularly to your nose, as it emits a putrid “rotten egg” smell.
Nitrates
Nitrates come from fertilizers and animal waste. They occur naturally in groundwater, but can also enter the water through agricultural or sewage runoff.
When consumed in large quantities, nitrates can be dangerous for infants and pregnant women, causing a condition known as “blue baby syndrome” where oxygen levels in the blood are reduced.
One of the issues that can come up in rural areas after major flooding or severe rainstorms is contamination from nitrates, as fertilizers and animal waste can be washed into water sources.
PFAS
Per-and polyfluoroalkyl substances (PFAS) are a class of man-made chemicals used in a variety of industries, including firefighting foam, nonstick coatings, and waterproofing materials. These chemicals have been linked to health.
PFAS can enter groundwater through industrial discharge or improper disposal of products containing the chemical. The EPA recommends regular testing for PFAS, especially if you live near an industrial site or have had a firefighting foam release nearby.
Although PFOA and PFOS are no longer manufactured in the States, they’re still prevalent in the environment and can continue to contaminate water sources.
MTBE
Methyl tert-butyl ether (MTBE) is a chemical added to gasoline as an oxygenate, improving the fuel’s combustion. It has been found to cause health issues, including cancer, and can enter groundwater through leaking fuel storage tanks or when gasoline is spilled.
MTBE can give water a distinct taste and odor, making it unpleasant to consume. It’s important to regularly test for MTBE, especially if you live near gas stations or fuel storage facilities.
Radionuclides
Radionuclides are elements that emit radiation as they decay, often occurring naturally in rocks and soil. They can also enter the environment through human activities such as mining and the burning of coal, nuclear weapons testing, and leaking radioactive waste storage sites.
Exposure to radiation can increase the risk of cancer and other health issues. It’s important to regularly test for radionuclides if you live near any of these activities that may release them into the environment.
Groundwater only becomes radioactive due to natural causes like radon, radium, or uranium. So when nuclear power plants and medical facilities release man-made radioactivity into drinking water sources, it also seeps into the ground.
Radon
Radon is a radioactive gas that occurs naturally in rocks and soil. It can enter homes through well water, as well as cracks in building foundations or other openings. Radon is the leading cause of lung cancer among non-smokers, and it’s important to regularly test for it in your home.
All rocks have uranium, but most only contain a very small amount. Just as radioactive decay causes uranium to be present in all rocks and soils, it also causes radium and radon to be present in rocks and soils.
Uranium
Uranium is a naturally occurring element that can enter drinking water through leaching from rocks and soil. It’s important to regularly test for uranium, as high levels in drinking water can increase the risk of kidney toxicity and cancer.
It can also be used in some industries, such as ceramics manufacturing and nuclear power generation.
Everyone ingests or inhales small amounts of natural uranium daily, but excessive exposure can cause health issues such as kidney toxicity and increased cancer risk. It’s important to regularly test for uranium, especially if you live near industries that use it or have natural uranium deposits in the area.
Trihalomethanes
Trihalomethanes (THMs) are a class of chemicals that form during the disinfection process of drinking water. These chemicals have been linked to health issues including cancer and reproductive problems, and it’s important to regularly test for THMs in your drinking water.
THMs can also enter the water through industrial discharges or the use of certain consumer products, such as chlorinated swimming pool water or household cleaners.
Trihalomethanes, a water by-product linked to cancer and reproductive problems, can form during the disinfection process and enter the water through industrial discharges or the use of certain consumer products. It’s important to regularly test for THMs in your drinking water.