Greater Peoria Metro Area, IL

Working with the community... for a healthier community.

Local Groundwater A Natural Resource to Protect!


By Kaylee Halberg, BS, Sanitarian

Groundwater is one of our most important natural resources and everyone plays a role in keeping it safe. Over half of the people in the U.S. rely on groundwater for drinking water and routine household use, so it is important to protect this water from contamination.

As rainwater and stream water move slowly down into the ground, the water fills cracks and spaces in the rock, sand, and clay beneath the soil. Water is stored there in these underground storage spaces called aquifers. Water can be removed from these aquifers by constructing water wells to pump the water out for everyday use. Almost all rural homes and some municipalities use water wells.

Drinking contaminated water from water wells can cause serious health problems, so everyone should be aware how easily groundwater can become contaminated. One source of contamination is from chemicals such as pesticides and fertilizers that can be carried in rainwater runoff and then mix with the groundwater. Once pollutants make their way down into the aquifers that store groundwater, it is very hard to remove them. From the aquifers, contamination could then be pumped from a well and directly introduced into drinking water.

Abandoned wells also present a potential source of contamination to groundwater. Abandoned wells are water wells that are no longer used to supply water or are in such a state of disrepair that they threaten public health. These old wells can provide a direct pathway for contaminants to enter the aquifers. An abandoned well may be nearby old windmills or pump houses. You might see telltale signs that old wells exist from pipes sticking out of the ground or slabs of concrete or plywood covering a hole in a yard. Because these old wells present a hazard to people and to groundwater, property owners are required by law to properly seal these abandoned wells.

Another major concern is contamination of groundwater from septic systems. An improperly designed and constructed septic system can cause bacteria, viruses, household chemicals, and other contaminants to enter the groundwater. The location and routine maintenance of a septic system are also important in keeping contaminants away from groundwater.

All homeowners have a responsibility to protect groundwater and ensure that wells and septic systems are not sources of contamination on their property. Private water wells should be inspected and tested annually, and whenever there is a change in the look or taste of the water. Routine preventative maintenance helps ensure water quality and is much less costly than emergency maintenance.

Most local health departments inspect new and repaired private water wells and onsite wastewater treatment systems in their counties. Water wells are tested for bacteria and nitrates. Some common bacteria such as E. coli can be very dangerous to humans and cause diarrhea, stomach cramps, and even kidney failure. High nitrates in groundwater are usually caused by malfunctioning septic systems and agricultural runoff. Nitrates are particularly harmful for pregnant women, infants, and children. Boiling water will not remove nitrates and may actually increase them.

Groundwater is important as drinking water, for irrigation, and in everyday use. When contaminants go into the ground, they don’t just go away. Everyone has a role in helping to protect our groundwater.

For more information on this environmental health topic and other important public health issues, visit the Peoria City/County Health Department website at

Photo credit: robertsrob/Thinkstock