Frequency

When to Test

Bacteria and nitrate - at least once per year.
Nitrite - at least once per year if you have high nitrates.
Arsenic and Manganese - at least once, or more often if you are in an area where other wells exhibit a change in arsenic levels.
Depending on the local geology and land use nearby your well, you may want to test for additional contaminants or test more frequently to look for high seasonal or an increase in overall contaminant levels.

Other reasons to schedule a well water test include:

Neighboring well owners are having problems with their water quality.
A change in color, taste, odor, hardness, corrosion, sediment, and anything else unusual with the well water.
When you find that any of the contaminants you test for are close to the Maximum Contaminant Level (MCL) recommended by the Environmental Protection Agency (EPA) and you want to continue to consume the water
After any well service
Flooding near your well site
When the well has sat idle for a long period of time without being used - like when you go south for the winter, or the home sits empty for more than a few weeks.

Coliform bacteria and nitrate are most likely to be found during wet weather, when runoff and excess soil moisture carry contaminants into shallow groundwater sources or through defects that may exist in your well's design, borehole or casing. In general, these are the wet periods of late spring and early summer as well as the wet periods of the fall.

Pesticides used on lawns, gardens, or farm fields are most likely to be present in greatest concentrations soon after they are applied. With the exception of large chemical spills, it takes excess soil moisture to carry pesticides into the ground which makes late spring and early summer good times to test for pesticides if they are one of your concerns.

For naturally occurring contaminants like arsenic, fluoride, and radium, testing can be done at anytime because these contaminants are relatively stable in the groundwater.

When Water is Unsafe to Drink

First and most important - stop consuming the water and find an alternative source for all of your consumable water needs. This can be bottled water, a neighboring water supply that is known safe, water from a public water supply like a neighboring town or city, or water that has been properly treated for the contaminants present in the water.

Then you should determine what the best short term and long term solutions are for your safe drinking water needs. Your options are to use bottled water for all consumable water needs, providing adequate water treatment at one or more drinking water taps, rehabilitation or renovation of the well or water system so that it provides safe water, connection to a known safe water supply, or replacement of your existing water supply.

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.

You should discuss the water quality issues with a Iowa 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 Iowa 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.

To obtain additional information on water system rehabilitation, renovation, repair or replacement, please contact your local Iowa DNR Certified Well Driller or Certified Pump Installer.