FREEPORT, ILLINOIS — As floodwaters rise, private wells can become contaminated, especially if they are located in a pit, recessed area or floodway. Surface water may contain a host of soluble or particle contaminants and collect around and over the well casing potentially allowing surface water to run down and around the well casing. As water is pumped from the well, surface water is more rapidly drawn into the drinking water supply.
Many well pits are not water-tight and act as funnels for surface water. If you notice a change in taste, smell or clarity of your well water, we recommend switching your drinking water supply to a different tested water source and testing your home well water supply.
One of the services offered by the Stephenson County Health Department’s (SCHD) Environmental Health Division is the testing of private wells. Coliform bacteria and nitrate are the two most prevalent contaminants of groundwater in Northwest Illinois. The SCHD has test kits available to property owners or renters including: bottles, boxes, instructions, form, shipping, testing and test results with explanations and recommendations. The fee for this service is normally 80.00 dollars. Due to the recent flooding, for a limited time Illinois Department of Public Health (IDPH) and SCHD are waiving the standard fee.
The best measures to reduce potential contamination of your well are make changes to the well or replace the well. Those changes may include: 1) house the electric supply line to the well pump in a conduit from below the ground surface extending into the casing cap. The connection needs to be air-tight, 2) replacement of the cap using a State of Illinois approved vented well cap which is fit tightly onto the casing, 3) extending the well casing to at least eight inches above the surface, 4) grading the surface around the well to assure surface water drains away from the well, 5) replace the damaged well cap gasket, 6) replace the pit-less adapter if it leaks, 7) well in a pit is extended to above the surface, a pit-less adapter installed, the pressure tank and controls moved out of the pit and into a heated space, and the pit collapsed and filled with clean fill material (ex.- pea gravel), 8) sealing an abandoned well within two hundred feet of the service well. Contact the SCHD Environmental Health Office for well sealing details and scheduling at (815)599-0344.
Before treating the well with chlorine, complete the improvements to the water system.
Chlorinate the system using the following steps: remove the well cap and pour chlorine in the inside of the well casing. The amount of chlorine needed will vary depending on the well depth. As a general rule, we recommend two to four gallons of unscented chlorine bleach and one to two cups of quick-release chlorine granules. If granular chlorine is not available, doubling the amount of chlorine bleach is recommended; attach a hose to the system, run outside faucet until a strong chlorine smell is present and rinse down the inside of the casing. Reinstall the well cap and proceed to run each faucet, including hot water, until a strong chlorine smell is present. Let the water stand in the water lines for 12 to 24 hours and then purge the system. The well may be retested after the chlorine has dissipated, (generally a week to ten days). The lab will check samples for chlorine and if chlorine is present, they will not test the water sample.