Well Water Testing Reveals The Truth

Well Water Testing Guide

Why should I consider well water testing?

There are certain contaminants which may be present in your well which can be harmful to your health, damaging to your home, increase your energy costs, and/or create a nuisance. By knowing what is in your well water you may then address those issues, protecting your health and/or pocketbook. As a private well owner it is your burden to test and treat the water flowing from your well.

How do I determine my well water composition?

Your county water department will often test your water for free but those tests are typically limited to bacteriological contaminants. They will not tell you if you have other potentially life threatening elements or chemicals in your well. The most thorough way to determine your well water’s composition is to have a sample analyzed by a certified laboratory for a broad range of contaminants – a full laboratory water test. Do-it-yourself test kits are good non-life threatening applications like swimming pool maintenance, but should be considered with caution when contemplating their use on your drinking water supply.

How frequently should I test the water from my well?

After the initial test is performed on a newly dug well, the EPA recommends you test it annually for microorganisms and once every two to three years for harmful chemicals and elemental contaminants. Also, be sure to test your well water if there has been flooding, earthquakes or other land disturbances in your area, if there are known problems with well water in your area, or if you have replaced or repaired any part of your well water system.

How do microorganisms, chemicals and other contaminants get into my well water?

Germs and chemicals can get into your well water and contaminate it in different ways. Some germs and chemicals occur naturally. For example, heavy metals like arsenic, lead, and selenium are naturally found in rocks and soil and sometimes seep into ground water. Other contaminants come from human and animal waste resulting from polluted storm water runoff, agricultural runoff, flooded sewers, or individual septic systems that are not working properly. Ground water and aquifers can also become polluted from industrial activity.

Total Coliform

Coliform bacteria are microbes found in warm-blooded animals’ digestive systems, in soil, on plants, and in surface water. These microbes typically do not make you sick, but because microbes that do cause disease are hard to test for in water, “total coliforms” are tested for instead. If the total coliform count is high, then it is much more likely that harmful germs like viruses, bacteria, and parasites might also be found in the water


Is your drinking water safe? Here’s how you can find out

America’s drinking water infrastructure is aging and in serious need of modernization. Pipes are overdue for replacement, and water and wastewater treatment systems need upgrades to deal with new classes of pollutants. Changing a drinking water standard or adding a new substance to the list of contaminants regulated by the Environmental Protection Agency is time-consuming. Some water systems are having problems meeting current standards, much less upgrading to meet new requirements.

A 2017 Gallup poll found that 63 percent of Americans worry a great deal about drinking water pollution. And a recent report from the Natural Resources Defense Council, Threats on Tap, suggests that they have good reason. According to the report, community water systems – public systems that serve cities and towns year-round – registered more than 80,000 reported violations of the Safe Drinking Water Act in 2015.

As water resource educators with Penn State University’s Extension service, our role is to educate the public using research-based information. Most of our work is focused on private water systems – mainly wells and springs, which are used by over 15 million U.S. households. These private systems share many of the critical concerns about public systems addressed in NRDC’s national report

Clean water and proper sanitation have greatly improved life expectancy in the United States over the past 150 years. Now, however, we see an urgent need to upgrade water infrastructure, and to update regulations, enforcement and public education about drinking water safety. With many public and private water systems across the nation aging and under stress, it is important for everyone to understand the risks associated with drinking water contamination, and to know how to take simple steps such as having their water tested if they suspect there may be a problem

Land use and source water protection

Delivering clean drinking water starts with protecting sources, including groundwater and surface rivers and lakes. Many water quality problems that we see in Pennsylvania are based on local land uses. Nitrates from agriculture and development are a particular problem in water wells in the southeast and south-central parts of the state. Exposure to nitrates in drinking water can cause health effects, especially in infants, inhibiting their blood’s ability to carry oxygen.


Testing farm drinking water

Is my water safe to drink?

If you do not monitor your water quality by having it tested at an accredited laboratory, you cannot tell whether your drinking water is safe or not. Harmful bacteria, parasites, and viruses are invisible to the naked eye, so water that looks and tastes good may not necessarily be safe to drink. These microbes can exist in both ground and surface water supplies, and can cause immediate health effects if not properly treated for.

Tests for drinking water

There are many useful tests available to help determine the health, safety and performance of your water supply depending upon its type and location. Your local health department can assist you in selecting tests important for assessing your drinking water.

Basic tests

Coliform bacteria tests are used as an indicator test for the presence of microorganisms in the water that are potentially harmful to human health. Nitrate is a common contaminant found mainly in groundwater. High nitrate concentrations can be particularly dangerous for babies under six months, since it can interfere with ability of blood to carry oxygen. Ions such as sodium, chloride, sulphate, iron and manganese can impart objectionable taste or odour to water. Excessive amounts of sulfate can cause a laxative effect or gastrointestinal irritation, along with a noticeable taste. Excessive amounts of fluoride can cause dental problems. Total dissolved solids represent the amount of inorganic substances (for example: iron, salts) that are dissolved in the water. High total dissolved solids (TDS) can reduce the palatability of water or cause health problems if specific constituent elements are at high levels.

Microbiological Indicators

Laboratory results may provide information on levels of Total Coliforms, Escherichia coli (E-Coli), and Heterotrophic Plate Count (HPC) which are used as microbiological indicators of the microbiological quality of the water. This section will briefly outline the rationale for including these indicators and their significance.

Total Coliform (TC)

The presence of Total Coliform bacteria may indicate contamination in a water supply. The presence of Total Coliforms alone is not necessarily a health risk, but it does require a further investigation of the water system. The presence of any coliform bacteria indicates that the sampled water is potentially unsafe and unsatisfactory.


Well Testing


The U.S. Environmental Protection Agency’s (EPA) rules that protect public drinking water systems do not apply to individual water systems, such as privately owned wells. As an individual water system owner, it is up to you to make sure that your water is safe to drink

What to test for

Several water quality indicators (WQIs) and contaminants that should be tested for in your water are listed below. A WQI test is a test that measures the presence and amount of certain germs in water. In most cases, the presence of WQIs is not the cause of sickness; however, they are easy to test for and their presence may indicate the presence of sewage and other disease-causing germs from human and/or animal feces. (Please see Water-related Diseases and Contaminants in Private Wells for a list of additional germs and chemicals in drinking water wells and the illnesses they cause.)

Total Coliforms

Coliform bacteria are microbes found in the digestive systems of warm-blooded animals, in soil, on plants, and in surface water. These microbes typically do not make you sick; however, because microbes that do cause disease are hard to test for in the water, “total coliforms” are tested instead. If the total coliform count is high, then it is very possible that harmful germs like viruses, bacteria, and parasites might also be found in the water

Fecal Coliforms / Escherichia coli (E. coli)

Fecal coliform bacteria are a specific kind of total coliform. The feces (or stool) and digestive systems of humans and warm-blooded animals contain millions of fecal coliforms. E. coli is part of the fecal coliform group and may be tested for by itself. Fecal coliforms and E. coli are usually harmless. However, a positive test may mean that feces and harmful germs have found their way into your water system. These harmful germs can cause diarrhea, dysentery, and hepatitis. It is important not to confuse the test for the common and usually harmless WQI E. coli with a test for the more dangerous germ E. coli O157:H7.


The pH level tells you how acidic or basic your water is. The pH level of the water can change how your water looks and tastes. If the pH of your water is too low or too high, it could damage your pipes, cause heavy metals like lead to leak out of the pipes into the water, and eventually make you sick.


Well Water Testing

Is my well water safe to drink?

If your drinking water comes from a private well, it should be tested by a lab to see if it is safe for you and your family to drink. Unsafe drinking water can make you sick. Even if you are not sick right now, your well water may not be safe. Some contaminants found in well water can cause long-term health problems. All water suppliers in B.C. are required to test their water regularly. This includes including small private systems, such as restaurants or trailer parks, cooperatively owned systems, such as strata properties, and larger municipal systems owned by local govern ents. Water samples are sent to qualified labs for testing.

Why might my well water be unsafe?

Your well water may taste and look fine, however, there can be many harmful substances that you cannot taste, see or smell, such as bacteria and chemicals that could affect your health. These can enter well water both from the surface and ground, and can be from natural sources or human activities. For example, nearby farming and agricultural activities or septic systems, if built or maintained improperly, could lead to increased nitrates and fertilizers seeping into soil and contaminating your well water. Poor well maintenance may also cause contamination of your well water.

Bacteriological Testing

Bacteriological testing should be done 2 or 3 times a year. Two common types of bacteria found in water are: Total Coliforms and E.coli

Escherichia coli (E. coli)

  1. coli originates in the intestinal tracts of animals. The presence of E. coli in your well water may mean fecal matter has entered the well. Fecal organisms cause stomach and intestinal illnesses, including diarrhea and nausea, and may even lead to death. Babies, children, elderly or people with immune deficiencies or other illnesses may be affected more severely

Chemical Testing

Chemical testing should be done on a routine basis, typically at a minimum every 5 years. Chemicals commonly of concern in B.C. groundwater are: nitrates, fluoride and metals such as arsenic, lead, copper and manganese.