Illinois backflow testing rule traces to Chicago’s 1933 water outbreak

Illinois still requires annual backflow testing for many properties, a rule rooted in the 1933 Chicago drinking-water contamination linked to cross-connected plumbing. A Fox Valley plumbing company is using Elgin’s 250th anniversary to spotlight the requirement and remind owners that compliance sits with the property owner.

Why it matters: - Annual backflow testing is a public-health safeguard meant to keep sewage, irrigation runoff and industrial fluids out of drinking water. - The rule affects many property owners, including commercial buildings, fire-suppression systems and homes with irrigation lines tied to city water. - A missed test can lead to fines and, in some municipalities, disconnection of service.

What happened: - Illinois requires every testable backflow prevention device to be inspected once a year by a state-certified inspector. - The rule applies even when the system is not currently in use. - Fox Valley Plumbing & Backflow is highlighting the requirement as Elgin marks America’s 250th anniversary in 2026. - The company said property owners who are unsure when their device was last tested can call (847) 624-3872 or visit foxvalleyplumbing.com.

The details: - The requirement traces to Chicago’s 1933 Century of Progress World’s Fair, when cross-connected plumbing at two downtown hotels allowed sewage into the drinking-water supply. - U.S. Public Health Service accounts recorded about 98 deaths and more than 1,000 illnesses across roughly 200 American cities. - The outbreak is regarded as the only known widespread outbreak of waterborne amoebic dysentery in a U.S. civilian population. - The response helped drive nationwide cross-connection control standards. - The Foundation for Cross-Connection Control and Hydraulic Research, now at the University of Southern California, was created in the aftermath. - Under the Illinois Plumbing Code, backflow assemblies must be tested at installation and at least annually after that. - Only a licensed plumbing contractor certified by the Illinois EPA as a Cross-Connection Control Device Inspector may perform the test. - Municipalities must run cross-connection control programs and survey water customers every two years to find missing, untested or improperly installed devices. - Some municipalities accept test reports directly. - Others use third-party administrators to track compliance and notify owners when testing is due. - Fox Valley Plumbing & Backflow files test reports with the City of Elgin, with BSI Online and with Aqua Backflow. - Aqua Backflow is the Elgin-based program administrator used by communities including Geneva and Carpentersville. - Fox Valley Plumbing & Backflow also files directly with villages that require it. - Responsibility for compliance sits with the owner, not the water utility.

Between the lines: - The rule is common enough to affect many properties, but obscure enough that many owners do not know it applies to them. - Local reporting rules create a compliance burden that varies by municipality, which makes the process harder to track without a licensed contractor. - The anniversary tie-in gives a plumbing compliance issue a broader civic frame, linking a modern requirement to a historic public-health failure. - Fox Valley Plumbing & Backflow is also using the moment to reinforce its local service role in the Fox Valley.

What's next: - Elgin’s 250th-anniversary programming will run through 2026 through the Enhancing Elgin Committee of the Elgin Area Chamber of Commerce. - The city’s commemorative events involve the Elgin History Museum, the Gail Borden Public Library, Elgin Community College and the City of Elgin. - Property owners who are unsure about their backflow test status may need to confirm the last inspection date before the next compliance deadline.

The bottom line: - Illinois backflow testing is not just a plumbing formality. It is a century-old safeguard that remains central to protecting drinking water today.