Well Testing

How to Find Out if Your Water is Safe

It's important to understand how protected your water source is based on your specific location, the land use practices in your area, your well's construction, and most importantly of all - frequent sampling and analysis of your well water. 

Older water supply wells - especially those constructed before 1982 - may or may not have adequate protections in place to ensure that the well obtains its water from deeper, protected aquifers. If you have an older well, or if you don't know the depth and construction details of your well, you should have your well water sampled at least yearly so that you know if you should consume the water. You should also consider hiring a DNR Certified Well Contractor to perform a thorough well inspection to determine if your well includes construction features that will help ensure the well only accesses water from known safe aquifers and that your well provides safe drinking water.

Knowledge of your water quality will empower you and help you make informed decisions about your consumable water and long term health. First and foremost, ensure that all the water you consume is safe. The only way to determine if your well water is safe to consume is to take a sample of the water and send it to a drinking water laboratory. Your local county environmental health office can help you arrange for testing or you can obtain a water sample test kit, sample the water yourself and send it to a certified drinking water laboratory for analysis.

How often you test your supply should be based on several things. They include what your previous water testing found, who is using the water, changes in the water quality you can see, taste or smell, and the type of potential contaminants applied to land near your well. 

At a minimum, all private well users should test their water supply at least once each year for a minimum of coliform bacteria and nitrates, and have at least one arsenic test performed on the well water. You should test your well more often if:

• You suspect or know your well obtains part of all of its water from a shallow aquifer or Karst bedrock.
• Previous testing found contamination.
• You have young children, senior citizens or immune compromised individuals using the water.
• Your water quality suddenly changes. Things like unusual tastes, odors, color or sediment.
• You have any well repair or pump and water system services performed.
• Neighboring wells of similar depth and construction have tested positive for contamination.
• One or more of your family members become ill and the symptoms do not seem to improve within a time period that seems normal based on your previous experiences.

Private Well Testing and Services

Iowa's Private Well Grants Program (PWG) provides free water testing to all private well owners and users for the analytes listed below. The DNR recommends that all private well owners have their water tested at least annually for the following parameters:

• Bacteria/E.coli/coliform  (annually)
• Nitrate (annually)
• Arsenic (every 3 years)
• Manganese (every 3 years)

In addition to private well testing, the PWG program offers funding for the private well related services listed below.

• $400 - Shock Chlorination (Form 542-0503)
• $600 - Well Assessment (Form 542-0502)
• $700 - Well Plugging (Form 542-1226)
• $400 - Cistern Plugging (Form 542-1226)
• $2,000 - Well Reconstruction or Renovation (Form 542-1519)

Obtaining Well Testing or Services:

1. Contact your county health department  and notify them that you want one of the above services.
2. Contact a DNR certified well contractor to perform the work. The bullets below tell what type of work each type of contractor can perform, and links to a list of those contractors sorted by their city of residence.
   1. Well Drillers  - Shock chlorination, well assessments, reconstruction, well plugging (except pump and plumbing work)
   2. Pump Installers  - Shock chlorination, well assessments, reconstruction (upper 10 feet only), well plugging
   3. Well Pluggers  - Can only plug Class 1 and Class 3 wells - all other well plugging must be performed by a well driller or pump installer
3. Non-certified contractors or non-certified people are not legally allowed to perform well services in Iowa, so always double check with the person you hire to ensure they are certified and on the lists linked above.
4. Tell the contractor you are seeking Private Well Grants funds and will require the following documents following completion of work:
   1. Fully completed DNR form based on the type of work (see forms linked above)
   2. Itemized "paid" invoice
5. Submit the documentation items to your local county environmental health department
6. The county will reimburse you directly once your required forms and invoice have been reviewed and approved.

More Testing Information

Private Well Grants - Guidance Document for Qualifying Services - this document provides detailed information regarding what types of wells and specific services qualify for PWG funding.

All water testing should be performed by DNR Certified Drinking Water Laboratories. These laboratories use accepted drinking water lab methods, employ highly trained staff to perform the water analysis, and use DNR-accepted standard operating procedures to help ensure your results are accurate. Laboratory analysis of drinking water requires controlled conditions, expensive technical equipment and highly trained professional staff.

If you are seeking testing for analytes that are not listed above, please contact your local county environmental health department to discuss your situation. If the county thinks additional testing is needed, the county may be able to contact the State Hygienic Laboratory to seek approval for further testing of more complex contaminants, or provide additional guidance to improve your water quality. Please see the State Hygienic Laboratory Private Well Water website to learn more. You may also contact any other Iowa certified drinking water laboratory, your local Iowa DNR Certified Well Contractor, or the Iowa DNR.

Contaminants - The Risk You Take When You Consume Unsafe Water

You increase your risk for illness and disease if you drink contaminated water. Each type of contaminant has its own health impacts depending on the level of contamination, how much of the contaminated water you consume and your individual sensitivity to the contaminant(s).

The term "consumable water" includes water that you drink and water used for mixing beverages, making ice cubes, preparing food, brushing teeth and rinsing mouth, and used for child's play. Depending on the type and level of contamination, consumable water also includes water used to wash dishes, wash hands, and shower or bathe.

Private wells do not fall under mandated state or national water quality standards. Because of this, you should use the EPA contaminant standards for public water supplies as the recommended standards for your private water supply. The presence of any contaminant above the EPA's maximum contaminant level (MCL) means that you should not consume the water without proper treatment, water system repairs that eliminates the source of contamination, or replacing the well with one constructed to provide safe water.

Here is some basic information on the most commonly detected drinking water contaminants.

• Bacteria, viruses, and protozoa are microorganism groups that contain pathogens that can cause waterborne diseases. When these microbes are present in your water supply, symptoms such as diarrhea, cramps, nausea, headaches and others are possible. Microbes can pose a much greater health risk for infants, young children, senior citizens and those with severely compromised immune systems.
• Nitrate in drinking water above 10 mg/L should never be given to infants less than six months old as it can cause a potentially fatal disease called blue baby syndrome" There are also indications that long term exposure to nitrate levels may lead to other health issues, but more research is needed in this area.
• Studies have shown that chronic or repeated ingestion of water contaminated with arsenic over a person’s lifetime is associated with increased risk of cancer of the skin, bladder, lung, kidney, nasal passages, liver or prostate, and noncancerous health effects like diabetes and cardiovascular, immunological and neurological disorders.

Normally, well testing includes coliform bacteria, nitrate, and nitrite. Testing for these contaminants is easy and inexpensive and it can be used to provide basic information on drinking water safety. There are also other water tests you should consider. Contaminants like arsenic, fluoride, nitrate, nitrite, and lead are naturally occurring in some aquifers and may require specialized water treatment to reduce or eliminate the exposure risk. You should also consider testing shallow wells periodically for pesticides.

The following table lists water-related diseases and contaminants that may be found in unsafe drinking water and provides links with additional information.

Additional Contaminant Information

For additional information on chemical contaminants and waterborne diseases, please see the following links:

• Private Wells and PFAS Overview (PFAS testing requires pre-approval from the DNR)
• EPA - Types of Drinking Water Contaminants
• Centers for Disease Control - Well Water Safety
• Iowa Department of Public Health - Private Well Water and Health

What to do if Testing Reveals Contamination

If your water analysis finds the water is unsafe for any contaminant, do not drink the water. You should obtain all of your consumable water from a known safe water source, like a well recently proven safe by water testing and analysis, a water source with a water treatment device connected to the supply that is designed to remove the contaminant(s), a public water supply, or you should purchase bottled water. This reduces or eliminates your immediate risk and allows time for you to investigate the options for managing your water system.

If you live in a Karst area and your well obtains its water from shallow groundwater sources that have been proven to be unsafe to drink and renovating or replacing your well is not an option, you should use a known safe alternative source for your drinking water needs or consider the use of a reverse osmosis water treatment system at each point of use where you want to obtain your drinking water. 

In some cases, the issues that can cause drinking water contamination are simple and can be remedied by adding protections to the existing well, or a simple point of use water treatment system. Other times, the only effective solution will be an alternative source of water.

Short term options if your water supply is contaminated:

• Use the well only for purposes that do not pose a health risk and use bottled water for all consumable purposes
• Install and maintain approved water treatment devices at each tap you obtain consumable water

Long term options if your water supply is contaminated:

First, contact a DNR Certified Well Contractor for consultation. They can help you make informed decisions, including:

• Can you modify your existing well to keep-out the poor quality water?
• Do you need to replace your well with a new well that includes additional construction features designed to improve your water quality?
• Is it possible to install and maintain approved water treatment devices at all taps where you obtain consumable water?
• Is it best for you to connect to a nearby public water supply if one is available?
• And as a last resort, can you use the well only for purposes where it does not pose any health risk and use bottled water for all consumable purposes?

Use a Certified Well Contractor

You should discuss any water quality issues and water system rehabilitation, renovation, repair or replacement with a DNR Certified Well Contractor. They can help diagnose your water issues and provide guidance on repairs or well replacement. Anytime you hire a contractor to work on your well or water system, the contractor must be certified by the DNR in the proper categories of well services.

Certification ensures that the individual you hire meets a minimum level of knowledge and skill in the areas needed for your job. It's important to note that you should select your contractor carefully because even though a contractor may be certified by the state, they may not have the equipment or the experience to perform all well services.

Additional Resources

• Water Treatment Options - Informational booklet by the State Hygienic Laboratory at the University of Iowa that provides a guide to well water contaminants and effective water treatment devices.
• Well Consumer Information Booklet - This booklet is designed to help private well owners understand private well construction and ownership.
• Iowa's Groundwater Basics - A geological guide to the occurrence, use and vulnerability of Iowa's Groundwater.  The publication is full of good information, interesting diagrams and wonderful pictures. Published by the Iowa Geological Survey.

Frequently Asked Questions