Water Wells FAQs

What methods of water well construction are used in Lake County?

The two major drilling methods used to construct water wells in Lake County are the rotary and the cable tool method.

Using the rotary method, a hole at least three inches larger than the well casing is drilled. The well casing (a rigid pipe that provides a sealed sanitary route to the water-bearing aquifer) is put into place after the well hole is drilled. The annulus (the space between the casing and the earth) is then filled with bentonite slurry (a manufactured clay product) or less commonly with cement. The casing is usually made of PVC plastic pipe, though galvanized steel or black varnished steel casing may also be used.

The cable tool rig drills a hole in the ground that is only slightly larger than the well casing. The well casing is driven into the ground at the same time that the hole is drilled. Plastic casing pipe is not strong enough to withstand the percussion force, so only steel pipe is used. The annulus is sealed with bentonite granules.

Other types of water well construction methods may also be used, though they are very uncommon. Examples include the auger method, hollow rod method, jetting method and driving method. The LCHD suggests contacting several water well contractors to obtain information about the method that would best suit your needs.

What should I do after I have hired a water well contractor?

Consult with your water well contractor to determine the most suitable location for your well. The well should be located as far as possible from any sources of contamination.

The information below shows the minimum distances that the code allows a water well to be located from a source of contamination. When you place your water well at these minimal distances, you are reducing the chance of contaminating your water supply.

Minimum Separation Distances

  • Some minimum separation distances for water wells:
  • Septic tank - 50 feet
  • Septic Field - 75 feet
  • Septic Field Expansion Area - 75 feet
  • Body of Water - 25 feet
  • Sewer Line - Clay Pipe or Thinner Than SDR 26 - 50 feet
  • Sewer Line - SCH 40, SDR 26 or Cast Iron - 10 feet
  • Cesspool - 150 feet
  • Leaching Pit - 100 feet
  • Footing Drains - 10 feet
  • In-Ground Swimming Pool - 10 feet
  • Structures With Roof Overhang - 2 feet

Submit Application

Once the proposed location of your water well has been determined, have the water well contractor submit an application to the LCHD. The permit fees pay for a portion of the costs of Health Department personnel reviewing the application and inspecting the water well after construction.

The submitted application must have the following information:

  • Lot lines and dimensions
  • House or building location
  • Location of all septic tanks, septic field or sewer (including surrounding properties)
  • Location of proposed and existing wells.
  • Proposed well location must meet the minimum separation distances to sources of contamination listed in the Illinois Water Well Construction Code (Section 920.Table C).
  • Proposed and existing water lines that convey water from the new well.
  • Provide the location of an available community water system if any or a statement that no community water system is available on your site plan.

The above information is usually provided on a septic plan layout. If the information is not available, then it must be provided on a separate sketch. To help the water well contractor fill out your water well permit application, please provide the information on the most recent plat of survey or site plan to scale, along with the Permanent Index Number (P.I.N.). The P.I.N. is located on your tax bill from the township assessor's office, and is also referred to as the tax I.D. number. You may obtain copies of the most recent plat of survey and the P.I.N. by contacting your township assessor's office.


Once the water well contractor has submitted the water well application and fee to the LCHD, the application will be reviewed and acted on within 10 to 15 working days. After the water well application has been approved, the water well contractor may start constructing the new water well.

If the application is rejected, the applicant will receive a written explanation of why the application was rejected, and the actions that need to be taken to obtain approval.

I am having difficulty installing my water well at the minimal distance from sources of contamination.  What should I do?

The Lake County Health Department understands that sometimes due to the size of the property, the minimal distances to a source of contamination cannot be maintained. In those cases, the department's water well ordinance does provide an option to alter those distances. This provision is called a variance. Once it has been determined that it is not possible to maintain the minimal distance, a decision must be made on the best possible location for the water well. After the water well contractor has determined what he believes is the best location for the well, a water well application and a written request for a variance, along with the required fees, must be submitted. The written request must include the reasons one is asking for a variance.

A Health Department field sanitarian will review the request and conduct a site visit to confirm if the best location has been chosen for the water well. In many cases staff will meet the water well contractor on site. After the office review and site visit, the field sanitarian will make recommendations to the Environmental Health Program Coordinator. The Environmental Health Program Coordinator will review all the information and either approve or reject the application based upon how the proposed water well could affect the safety of the groundwater supply.

If your variance request has been rejected, then you may make a written request for a hearing with the Board of Health Hearings Committee. The Hearings Committee, under Lake County Code, Chapter 176, will consider hardship and will either approve or reject the application based on all information and recommendations provided. If the Hearings Committee denies your request, you may appeal their decision to the Board of Health.

Note: If you or your water well contractor have a difficult time in determining the best suitable location for the water well, our field staff and administrative staff are available to assist you.

What should I do after the water well has been installed?

Once you have installed your water well, you need to have the well inspected and a satisfactory water sample needs to be obtained before final approval is given.

When you are ready to have the water well inspected you can contact the LCHD to set up an appointment. Inspection appointments can be scheduled at our Lake County Central Permit Facility between the hours of 7:30 a.m. - 4:30 p.m. Monday through Friday (847-377-8020). When it is time to have your water supply sampled, you can have the sample collected either by your water well contractor, a private licensed sanitarian or LCHD staff. If the Department collects the sample, a nominal fee will be charged. Samples can be brought into our facility Monday - Thursday between the hours of 7:30 a.m. -3:30 p.m. The results of your water analysis (coliform bacteria/nitrate/nitrite) may be obtained from the Department in approximately 3 working days.


Before a water sample can be collected, the chlorine that the water well contractor adds to the well to disinfect it after its construction must be removed by running the water (flushing). If your residence is serviced by a septic system, the Department recommends when you flush the chlorine from your well and plumbing using an outside spigot. This can be accomplished by attaching a garden hose and discharging the water away from your septic system. After there is no longer a detectable chlorine odor, run all faucets in the house until they are also flushed free of the chlorine. Since the sense of smell is not an accurate indication that chlorine is present, we recommend the use of a chlorine test kit.

Water Sample

Once these field tests have been conducted, and the absence of chlorine has been confirmed, the sanitarian will collect a water sample from any permanently installed inside fixture. This fixture could be a sink or a permanently installed threadless faucet near the pressure tank that is at least 18 inches above the floor. The LCHD laboratory analyzes the sample for the presence of total coliform and E coli bacteria. A nitrate/nitrite analysis will also be performed.

If the water analysis is satisfactory, (no coliform bacteria present and nitrates at or below 10 milligrams per liter and nitrites are at or below 1 milligram per liter), the water well will be approved for human consumption.

Note: No one should use the water for drinking, bathing, washing dishes and all skin contact should be avoided until it has been tested and approved.

What should I do if my water analysis comes back unsatisfactory?

The most important thing to remember when one receives an unsatisfactory water sample is to not drink the water because there could be harmful bacteria present in the water supply. Depending on the results of the water analysis the following actions should occur:

Bacteriological Results

No total coliform bacteria. No E. coli bacteria. Results reported as A, A.NoneWater meets the standards for drinking water.

Positive coliform.
E. coli bacteria. Results reported as P, A.

Excessive bacterial growth present. No coliforms present. Invalid sample. Results reported as G.

Either chlorinate or flush the water system 1-2 days and make arrangements for the collection of a re-sample. In most situations you will need to chlorinate.See following notes: 1,2,3,4.
Positive coliform. Positive E. coli bacteria. Results reported as P, P.Chlorinate the water well and distribution system, make arrangements for the collection of a resample after the chlorine has dissipated from the water well.See following notes: 2,3,4,5.

Nitrate/Nitrite Results

Nitrate is less than or equal to 10 mg/L

Nitrite is less than or equal to 1 mg/L
NoneLevel meets the standards of drinking water.
Nitrate is greater than 10 mg/L 

Nitrite is greater than 1 mg/L
Flush the water system 1-2 days and make arrangements for the collection of a re-sample.

If after flushing you still obtain these results contact a water treatment company to install the necessary treatment to reduce nitrate levels.

See following notes: 2(b)

If after treatment, satisfactory nitrate levels cannot be obtained, it may be necessary to construct a new water well and abandon the existing old well.

Notes on Water Sample Results

  1. If you obtain unsatisfactory or invalid sample results, you may choose to flush or chlorinate the water well and distribution system. After the water well has been chlorinated the chlorine must be flushed from the water well prior to the collection of a re-sample.
  2. If any of the following circumstances have occurred, a satisfactory sample of the water must be obtained prior to final approval of the water well.
    1. The presence of coliform bacteria is confirmed in a water sample. Coliform bacteria may be an indicator that more harmful organisms are present. When coliform bacteria are present the water does not meet the standards for drinking water and should not be consumed.
    2. When the nitrate is >10 mg/L and/or the nitrite is >1mg/L the water does not meet the standards for drinking water and should not be consumed by pregnant women and infants less than 6 months of age. 
  3. When the water distribution system is flushed, the LCHD recommends that you run the water for several hours. Running the water should not damage the pump, but it is best to consult your water well contractor if you have concerns.
  4. Remember, if your residence is served by a septic system, the distribution system should be flushed from an outside spigot. Attach a garden hose and run the water away from your septic system.
  5. If E. coli bacteria are confirmed to be present in your water supply, you should chlorinate the well and plumbing system immediately. E. coli bacteria are found in the intestines of animals and man and increase the likelihood that disease-causing organisms are present in the water.

Do I need a treatment system for my water supply?

There are different treatment systems that are available for your water supply. For example, water softener is for hardness removal, charcoal filtration is for taste/odor control, and reverse osmosis is used to remove contaminants; arsenic, beryllium, fluoride, radium/uranium, sodium/chloride, pesticides, herbicides and some metals. To determine if you need a water treatment device, the Lake County Health Department recommends that you either contact a reputable water treatment company or a licensed water well driller who also sells and services water treatment equipment.

I have an existing water well and just installed a new well or connected to a public water supply. What should I do with the existing water well?

If the old water well is not used, it is considered abandoned and must be sealed since it provides a pathway for pollutants to enter the ground water. The Lake County Code, Chapter 170 and the Illinois Water Well Construction Code both indicate that an abandoned well must be sealed within 30 days after its use is terminated. Have the water well driller contact the Lake County Health Department a minimum of 24 hours prior to the sealing of the old water well. A representative from the department will verify the sealing of the water well. The old well should be sealed within 30 days of approval of the new well. If public water supply is made available to a dwelling with a well, a well contractor should apply and pay for a Lake County Health Department water well sealing application. The Lake County Health Department should be contacted a minimum of 24 hours prior to the sealing of the water well. A representative from the department will verify the sealing of the water well. The old well should be sealed within 30 days of the dwelling being connected to the municipal supply. If one desires to maintain and use their well as a non-potable water supply for outdoor watering, you must contact the Lake County Health Department to schedule an inspection to determine if your well is in compliance. Once the well has been determined to be in compliance the well will be required to be registered as a “Supplemental Irrigation Well” at the Lake County Recorder of Deed’s Office for a fee.

Can water wells be shared by two or more houses?

Lake County Ordinances do allow sharing wells in certain circumstances. Please contact us for further information at 847-377-8020.

How often should I have my water well tested?

The Lake County Health Department recommends all water wells be sampled at least once a year for coliform bacteria and nitrate/nitrite. If you have additional concerns or questions, please contact us at 847-377-8020. Our staff will gladly help you obtain a water supply that meets the Illinois Department of Public Health standards for drinking water.

How healthy is your well water?

Many of us receive annual medical check-ups by our family physician, but when was the last time your water well was checked by a licensed water well contractor? Many homeowners take their drinking water for granted and have expectations of a limitless flow of water, and most water systems are not inspected until it is required for a real estate transaction or refinancing.

Preventative maintenance is the key to insuring your water well system continues to function properly and safely. A well contractor can easily evaluate your water system, usually in less than 30 minutes. .

Here are some of the preventative measures you can do yourself to avoid future water problems in your home:

  1. Collect a water sample from your water well at least once a year. Test for coliform bacteria and nitrates, which are the two primary indicators of drinking water safety. The water samples should be analyzed by a state certified laboratory.
  2. Look at your pressure tank, check for leaks and tank cycling. Pressure tank cycling is identified by a “click, click” sound made by the pressure switch when the pump turns on. A cycling pressure tank greatly reduces the life of a submersible pump and may either need to be recharged with compressed air or need replacement. A licensed well contractor can do this work for you.
  3. Check your well cap to insure the cap is not loose. Check for openings or holes in the well cap, casing and the electrical conduit.
  4. If you have a water softener, keep your brine tank full with salt. Use clean white salt pellets instead of the less expensive gray rock salt. Always reset the water softener timer after each power outage so the softener does not backwash during normal hours of use.
  5. If you suddenly experience low water pressure contact a licensed well contractor to diagnose the problem. The problem could be as simple as a valve that was left partially closed or something more serious as a bad submersible pump.
  6. If your water well is located in a pit or vault below the ground surface periodically check the well pit for flooding. If the well pit is flooded and the cause of flooding could not be determined and or easily repaired contact a licensed well contractor to bring the well up to code by extending the well casing out of the pit or vault. If a pit floods, the wellhead may become submerged with the possibility of your water well becoming contaminated. After all the work is completed make sure someone collects a water sample to test for coliform bacteria and nitrates. Water sample bottles can be picked up at the Lake County Central Permit Center.

Taking these simple steps can help extend the life expectancy of your water well system, save you money and the potential inconvenience of not having water and can help insure your water is safe to drink.