Wells: Private Water Supply

What is a well?

A water well is a system of delivering water to a private home in an area where there is no integrated water system. Most towns and cities have public water works that have rigorous testing standards and deliver water to a large number of homes. Private water wells offer a water supply to single households, predominantly in rural areas where there is no public water system. Only those water well contractors licensed through the Illinois Department of Public Health are allowed to construct water wells. A listing of local water well contractors can be requested from the Environmental Health office.

Why would I get my well water tested?

Because a well is a private water supply, there are no required tests or treatments provided to said supply, as there are in public supplies to ensure proper safety. Although a properly constructed and located well should not contain contaminants, work done to the well may contaminate your water supply. This may include replacement of the well seal or pump. Flooding in the area of the well may also contaminate the water supply. Finally, after an unexplained illness in your household, a doctor may recommend that your water is tested for contamination.

IDPH labs can test for coliform and nitrates. These are indicators, which means their presence may indicate the presence of other contaminants in your water. IDPH recommends that new wells and wells that have been repaired be tested to determine if the water supply is safe. More information regarding sampling for coliform and nitrate can be found on the IDPH's website. For more questions about water testing, contact the CCHD Environmental Health office.

A free water test through IDPH is included with the construction of a new well. Once your well is completed, the pump has been installed, and the system has been chlorinated and allowed to sit for approximately 30 days, contact the Environmental Health office to set up a time for a water sample to be collected. It is recommended that the chlorine be allowed to dissapate for 30 days before sampling so residual chlorine in the water does not affect the results of the water test. Once the results from the test have been received (usually within 1 week of collecting sample), Environmental Health staff will interpret the results and provide the well owner with any recommendations if the test indicates an unsafe sample.

If your well is not new and you would like it tested, a homeowner can collect a water sample and send it in themselves using a test kit provided by the health department. Please contact the Environmental Health office if you would like a sampling kit to test your water. Samples from these homeowner sampled kits are sent to the Illinois Department of Agriculture lab for testing.

Contaminated water can cause illness, referred to as waterborne illnesses. Numerous pathogens can be involved in waterborne illness outbreaks. Examples of bacterial pathogens include Shigella, E. coli, and Salmonella. Parasitic pathogens include Giardia and Cryptosporidia. Norovirus can also be involved in waterborne illness. More information about these and other pathogens can be found on CCHD's foodborne illness page.

Some wells may also have a high nitrate content. Sources could include agricultural runoffs, industrial waste water, private sewage disposal systems, and animal feedlots. High levels of nitrates in drinking water can be dangerous to infants because they can cause a condition known as methemologlobinemi a, more commonly known as "blue baby" syndrome. This name comes from the bluish color the baby's skin turns if it is affected. Prompt medical attention should be sought if this condition is observed. Boiling the water will not decrease the nitrate concentration; instead, the concentration will increase with boiling. An alternative water source should be used for infant formulas if you water is high in nitrates.

What are different types of wells?

Types of wells include drilled wells, bored wells, driven wells, and monitoring wells. The most common wells that are constructed in Crawford County for private home use are drilled wells and bored wells.

Drilled wells are most often deep and relatively narrow with depths usually greater than 80 feet and hole diameters less than 10 inches. How to disinfect your drilled well

Bored wells are generally more shallow and wider with depths of 30-60 feet and hole diameters up to 3 feet. This type of well is generally constructed in locations where the water producing aquifer is shallow and low yielding. Because they are constructed in low yielding aquifers, bored wells with large diameters serve as storage reservoirs to provide water during high usage periods. These type of wells are generally more prone to contamination from the surface due to their shallow depth and lack of natural water filtration through the soil. How to disinfect your bored well

Driven wells are usually constructed in areas with very sandy or gravelly soils. The drive point is driven into the ground with equipment or can be done by hand.

Monitoring wells are constructed to determine groundwater quality or quantity.

I have an abandoned well on my property. What should I do?

Abandoned wells are required by Illinois law to be sealed within 30 days of being abandoned by a licensed well water driller or property owner/tenant. Refer to the Illinois Water Well Construction Code for the proper procedures and methods for sealing an abandoned water well.

For more information on...

Illinois Water Well and Pump Installation Contractors License Act and Code: www.ilga.gov/commission/jcar/admincode/077/07700915sections.html

Illinois Water Well Construction Code: www.ilga.gov/commission/jcar/admincode/077/07700920sections.html

Illinois Water Well Pump Installation Code: www.ilga.gov/commission/jcar/admincode/077/07700925sections.html

Water well permit form: www.idph.state.il.us/forms/ohp/water_well_permit.pdf

Water wells: www.idph.state.il.us/envhealth/waterwells.htm

Drilled wells: www.idph.state.il.us/envhealth/factsheets/drilledwlsFS.htm

Bored wells: www.idph.state.il.us/envhealth/factsheets/boredwlsFS.htm

Abandoned wells: www.idph.state.il.us/envhealth/factsheets/abndwlsFS.htm

Non-community water systems: www.idph.state.il.us/envhealth/watersupplies.htm

Emergency Water Supply: www.idph.state.il.us/envhealth/factsheets/emergcyh2o.htm

Water related diseases, contaminants, & injuries: www.cdc.gov/healthywater/disease/type.html

CDC Private Water Systems: www.cdc.gov/healthywater/drinking/private/index.html

Search for Water Well Contractors: ehlicv5pub.illinois.gov/Clients/ILDOHENV/PUBLIC/WaterWellContractor_Verifications.aspx