Illinois 2013 Beach Water Quality Summary
The Beaches Environmental Assessment and Coastal Health (BEACH) Act helps states and local governments develop monitoring programs to protect public health. Through these programs local officials test beach water for bacteria and issue closings or advisories when bacteria levels exceed a certain threshold. The EPA recently issued a new Beach Action Value (BAV), which is a more protective threshold than the national allowable bacteria levels used in previous years to trigger beach advisories. The EPA considers the BAV to be a "conservative, precautionary tool for making beach notification decisions." While the use of the BAV is currently optional, the EPA's proposed National Beach Guidance and Required Performance Criteria for Grants would require states receiving BEACH Act funding to use the BAV to trigger beach notifications. In light of this information, in assessing 2013 beach water quality NRDC has chosen to use the BAV in order to best protect beachgoers from water quality health risks.
Illinois has public swimming beaches along approximately 60 miles of Lake Michigan shoreline. The Illinois Department of Public Health administers the state's coastal beach monitoring program. Beachgoers can find advisory information on the Chicago Park District website.
What Does Beach Water Monitoring Show?
In 2013, Illinois reported 63 coastal beaches and beach segments, 49 of which were monitored. Of all reported beach monitoring samples, 10% exceeded the Beach Action Value (BAV) of 190 E. coli bacteria colony forming units (cfu) per 100 ml freshwater in a single sample. NRDC considers all reported samples individually (without averaging) when calculating the percent exceedance rates in this analysis. This includes duplicate samples and reported samples taken outside the official beach season, if any.
The beaches with the highest percent exceedance rates of the BAV in 2013 were Montrose Beach in Cook County (31%), South Shore Beach in Cook County (31%), North Point Marina Beach in Lake County (23%), Winnetka Elder Park Beach in Cook County (22%), and Rainbow Beach in Cook County (21%).
Illinois Water Quality Trend 2009–2013
The bar chart below illustrates the general trend of beach water quality exceedance rates in Illinois over the past five years. Note that only samples from a common set of 27 beaches monitored each year from 2009-2013 are included in the bar chart. Percent exceedance rates in 2009-2012 are based on the national single-sample maximum standard for designated beach areas of 235 E. coli bacteria cfu/100 ml water that was in place during those years. For comparison purposes, exceedance rates for 2013 are shown based on the historical national standard of 235 E. coli bacteria cfu/100 ml water, as well as on the EPA's new Beach Action Value of 190 E. coli cfu/100 ml water.
Percent of Samples Exceeding Daily Bacterial Maximum for Beaches Reported 2009-2013
- % exceedance of national standard in place 2009-2012
- % exceedance of national BAV safety threshold
* Please note exceedance rates for 2013 are shown based on the new BAV safety threshold and the historical national standard for comparison purposes. Additionally, only samples from a common set of beaches monitored each year from 2009-2013 are included in the bar chart.
Illinois 2013 Monitoring Results