Lead Regulation

In 1991, the Lead & Copper Rule (LCR) was enacted under the Safe Drinking Water Act. This regulation set action levels for lead and copper in drinking water. An action level is the concentration of a substance in a water sample that alerts that further action is needed. For lead, the action level is 0.015 mg/L, or 15 ppb. Action levels are not health standards but are set to limit the amount of lead and copper in drinking water.

Compliance Sampling

Under the LCR, the City must collect samples from pipes and plumbing fixtures on public and private property. City of Aurora water customers voluntarily assist the City to comply with this requirement by collecting water samples from their home tap. The Illinois EPA controls the sampling procedures and timing of sample collection.

Corrosion Control

To prevent lead from pipes dissolving into drinking water, the City uses a method of water treatment called corrosion control. The City uses alkalinity and pH adjustments as corrosion control methods. These parameters are measured four times a day, every day, to ensure corrosion control is effectively reducing the amount of lead entering drinking water.

Lead and Copper Rule Revisions (LCRR)

In 2024, the Lead and Copper Rule Revisions (LCRR) took effect, which strengthened the sampling and monitoring requirements for lead in drinking water to be more protective of public health. The LCRR placed regulatory emphasis on:

  • Identifying lead water service lines by creating a materials inventory; 

  • Changing sampling requirements to prioritize sites with lead service lines; 

  • Introducing trigger level to inform actions, in addition to existing action level; 

  • Increasing testing; and  

  • Developing programs for lead service line removal or replacement.

The LCRR was later adopted as a State of Illinois law. This means that all water systems in Illinois, including the City of Aurora, must comply with the LCRR starting October 16, 2024.

Lead Concentration Chart

As a result of increased testing requirements under the LCRR, concentrations of lead in drinking water are shown to be higher than previously determined under the LCR. The results from required lead sampling conducted since 2004 are shown in the chart below.

Lead Concentration in Drinking Water Data Chart.
Gráfico de datos de concentración de plomo en agua potable.

The City of Aurora's drinking water was in full compliance with the LCR through 2024. The most recent round of sampling was completed between January 1 through June 30, 2025, to comply with the LCRR. Results from this sampling period show an action level exceedance (ALE).  

An ALE does not mean that all drinking water contains lead. An ALE requires that the utility notify its customers and provide information to help prevent potential exposure to lead in drinking water.  

The City is taking the following steps to prevent potential exposure to lead in drinking water: 

  • Ongoing sampling to monitor lead levels throughout the water distribution system.  

  • Educating the public on steps they can take to reduce lead exposure.  

  • Ongoing removal of lead service lines throughout the City.  

  • Evaluation of corrosion control water treatment modifications to reduce the amount of lead dissolving into drinking water from pipe and plumbing components.

Corrosion Control Optimization Study

At the request of the Illinois EPA, the City began a study in March 2023 to improve its corrosion control practices. The City has been working with CDM Smith and Illinois EPA to evaluate the initial study results. So far, the City’s study has shown that a new chemical treatment will further reduce lead in the City’s drinking water. This study will continue through August 2025. The City is planning to proceed with construction to its corrosion control system following Illinois EPA’s approval.

For more information about the corrosion control study, you can contact the City of Aurora at 630-256-3250.

Lead and Copper Rule Improvements (LCRI)

On October 8, 2024, the EPA published Lead and Copper Rule Improvements (LCRI), which made updates to the LCRR. The LCRI requires stricter monitoring and sampling, including lowering the action level and changing tap sampling methodology. The current LCRI compliance date is November 1, 2027.

To learn more, visit https://lead-service-cityofaurora.hub.arcgis.com/.

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