Village of Oswego
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Important information about your drinking water 

Updated May 19, 2017

Providing safe drinking water to the Oswego community is extremely important to the Village of Oswego, and as such the Village monitors public drinking water for specific contaminants on a regular basis. To that end, the Village returned Well 4 to service on Friday, May 19, 2017 only after receiving notice from the Illinois Environmental Protection Agency (IEPA) that water from Well 4 is in compliance with state regulations. 

The Issue: Well 4 was taken off line in April after the Village was notified the well exceeded the allowable levels of radium in the water. Radium is a naturally occurring element found in groundwater supplies that may pose a health hazard when used for drinking or cooking. While all radium exposure carries some degree of risk, the IEPA established a maximum contaminant level (MCL) of 5 picocuries per liter (pCi/L) for combined radium in public water supplies. The MCL is well below levels for which health effects have been observed and therefore is assumed by the IEPA to be protective of public health. While combined radium levels may exceed 5 pCi/L over a single test, the IEPA requires public notice to be given if the rolling average of four quarterly tests exceeds 5 pCi/L. In the case of Well 4, the most recent quarterly test resulted in an annual average of 5.7 pCi/L, exceeding the IEPA’s MCL level of 5 pCi/L. 

The Village of Oswego contracts with Water Remediation Technology LLC (WRT) to remove radium from our public water system. The system has been successfully in place since 2005. The WRT system uses a filter that collects radium. Over time, the filter becomes less effective and must be changed out. This did not happen in a timely fashion and resulted in higher levels of radium were released into the water. 

What the Village Did to Resolve the Issue:  Upon receiving notice from IEPA of the concern, the Village removed the well from service and increased pumping from other wells to ensure residents would see no disruption in service. The Village operates a total of eight wells. All other wells are in compliance with IEPA regulations. 

We worked with our licensed radiological contractor to remedy this problem by replacing the filter that removes the radium from the water at Well 4. Once the filter was replaced, a licensed water laboratory analyzed the water.  The results indicated a combined radium level of 0.5 pCi/L, bringing the running average to 4.3 pCi/L which is below the MCL. 

What is the Village Doing to Prevent Future Issues:  The Village has revised internal policies to ensure that all required tests are completed during the required period, and that appropriate action is taken based on those tests in order to remain incompliance.  The Village has also hired a consulting engineering firm to conduct an independent audit of the operating procedures of the Utilities Division. 

What do Residents Need to Do:  You do NOT need to use an alternative (e.g., bottled) water supply. However, if you have specific health concerns, consult your doctor. This is not an immediate risk. If it had been, you would have been notified immediately. However, some people who drink water containing radium in excess of the MCL over many years may have an increased risk of getting cancer. 

Where Can I Get More Information: 

More information on radium in drinking water can be found at the following websites:  

For more information about the Village’s system, please contact Public Works Director Jennifer Hughes at 630-554-3242 or 100 Parkers Mill Oswego, IL 60543.