You are here


Cross Connection / Backflow Preventer Water Use Survey

Why did I receive a water survey from the City and Aqua Backflow?

The Illinois Environmental Protection Agency (IEPA) requires every water supply to develop and implement a cross connection (backflow prevention) control program.

A requirement of the program is to send a survey to all residential water customers every two years.  Initial survey requests were sent out earlier this year. If you received another survey (a 2nd Notice), it is because your first response was never received.  All water customers are required to complete and return this survey, which takes only a few minutes.

How do I respond to the survey?

Residents may complete the survey by filling out the card that was mailed and returning it to the address noted on the survey. Surveys can also be dropped off at City Hall or at the Public Works facility. The form can also be faxed, both sides, toll-free to 866-777-2125.

The survey can also be completed online. Residents may go to, click on the Forms tab, enter the password of “stc”, and complete the appropriate survey.  Please note there are some required fields but not all fields need to be filled in.

What is a cross connection and a backflow preventer?

Cross connections are potential connections between a potable water supply and a non-potable source, where it is possible for a contaminant to enter the drinking water supply.  Cross connections should be protected by a valve called a backflow preventer.  A backflow preventer is a device that allows the water to flow only in one direction and prevent the piping or device hooked to the water supply line from flowing back into it.

Backflow preventers are the property of the water customer and the responsibility lies with the customer for required annual testing and maintenance. The water customer must contract with a licensed tester to perform the required annual tests and any necessary repairs. Most plumbing contractors are now certified to test backflow preventers.

Where would a backflow preventer be found on a water customer’s piping?

Residential backflow preventers may be found on lawn irrigation systems, hot water heating (boiler) systems, swimming pool fills, water features, etc.

What happens if I do not fill out the survey?

All water customers are required to complete and return this survey. There are no penalties or fines for not completing the survey. However, we encourage everyone to complete the survey to assist the City in compiling accurate records and meeting compliance with IEPA.

Who is Aqua Backflow?

Aqua Backflow is the contractor hired to implement and oversee St Charles’ backflow program. They specialize in cross connection control management. If you have or require backflow protection, you may be notified for compliance (testing, repairs, installations, inspections, or surveys). Aqua Backflow can be reached locally at 866-777-2124 with any questions. The St Charles Public Works Department can be contacted at 630-377-4405.

The St Charles Cross Connection Control Program is designed to safeguard public health.  We ask for your cooperation with our program and any requests for information that come from Aqua Backflow or City staff.

How hard is my water?

Because we have seven wells with unique characteristics, water hardness in the distribution system varies, depending the proximity of your home to the different wells. Please refer to the water hardness map to determine the hardness of the water in your area.

Report a Water Main Break

To report a water main break, please call the main Public Works Department number, 630-377-4405.

If it's after hours, you will be prompted to leave a voice message in the appropriate mailbox. Include your phone number and address and the Public Works staff member on call will get back to you.

In an emergency, please call 911 immediately.

Also, please be reminded that St. Charles Connect is not monitored after hours and should not be used to report an emergency situation.

Rusty Water

You may notice rusty-colored water when a water main breaks, hydrants are flushed, or other work has been done in the area. This can make the water temporarily appear rust-colored because the iron and other mineral deposits in the water mains get stirred up.  There is no health hazard associated with discolored water.  Water is safe to use and consume during hydrant flushing, however it may stain laundry.

Simply turn on the cold water tap until the water runs clear.

Remember rust-colored water is safe, but it may stain laundry. If this happens, keep clothes wet and treat them with stain remover. The City offers a stain removal product at no cost to residents at the following locations:

  • Public Works, 1405 South 7th Avenue
  • City Hall, Reception Desk, 2 East Main Street
  • Police Department, 211 North Riverside Avenue