Wisconsin 2012 Beachwater Quality Summary
Reported Sources of Beachwater Contamination
(number of closing/advisory days)
- 668 (96%) unknown contamination sources
- 28 (4%) stormwater runoff
Wisconsin has 193 public beaches along 55 miles of Lake Superior and Lake Michigan coastline. The Wisconsin Department of Natural Resources (DNR) coordinates the state's beach monitoring program and administers BEACH Act grants.
What are the Water Quality Challenges and Improvements in Wisconsin?
Racine's Beach Program Demonstrates Excellence
In June 2012, the city of Racine began using rapid molecular methods (quantitative polymerase chain reaction, or qPCR) to determine whether to issue water quality notifications to swimmers at North Beach and Zoo Beach. These are the first locations in the nation where beach management decisions rely on DNA-based measurements of E. coli. Previously approved methods for determining levels of fecal indicator bacteria in beachwater depend on the growth of bacteria colonies in cultures and require 18 to 24 hours to produce results. The delay between sample collection and results means swimmers do not know until the next day if the water they swam in was contaminated. The delay can also mean that beaches remain under advisory or closed after water quality has improved.
In addition to qPCR, Racine has also developed beach-specific models using the U.S. EPA's Virtual Beach software program. Virtual Beach is a predictive model building tool that turns sanitary survey data into estimations of fecal indicator bacteria concentrations. By using a "Nowcast" model in conjunction with qPCR, Racine can consistently deliver same-day test results, generally within three hours of sample collection. This work demonstrates that sanitary surveys not only are useful for identifying pollution sources, but also support rapid analytical and decision-making tools.
Sanitary survey data have driven a variety of coastal remediation measures in Racine, including construction of a wetland to manage stormwater, restoration of dunes to infiltrate runoff from impervious surfaces, alterations in beach grooming techniques to reduce bacteria in beach sands, and improved best management practices. The use of sanitary survey data for identifying pollution sources has now gone upstream, as Racine officials use a modified version of this tool to assess infrastructure integrity and tributary health. Working with the School of Freshwater Sciences at the University of Wisconsin-Milwaukee to analyze stormwater samples for human-specific Bacteroides markers, they have identified and remediated three sites where sanitary sewage was infiltrating the storm sewer system. Sewage can enter storm drains when sewage lines leak into the drains, when inadvertent cross-connections are made, or when toilets or other sewage-related equipment in residences or commercial buildings are illegally connected to storm drains.
Stormwater Runoff Control Efforts Under Way in Kenosha
During heavy storms, bacteria carried by the Pike River contaminate water quality at three of the five beaches in Kenosha. The city, in conjunction with the Racine Health Department, conducts stormwater monitoring and microbial, chemical, and physical assessments within the Pike River watershed in support of a watershed restoration plan that will improve beachwater quality. In 2012, the city began reconfiguring a stormwater outfall at the beach in Pennoyer Park, and vegetated swales that reduce the amount of stormwater runoff will be installed within the watershed. Residents are also encouraged to install rain gardens in order to reduce the volume of stormwater that reaches the beach.
Sanitary Surveys in Wisconsin
Thanks to projects funded by the Great Lakes Restoration Initiative, extensive sanitary surveys (with special sampling studies if necessary) are also being conducted at all Lake Michigan and Lake Superior beaches that are unmonitored or under-monitored as well as those whose waters are listed as impaired. These cost-effective surveys identify pollution sources and in many cases also indicate ways to eliminate them. In some cases the surveys provide information about environmental conditions that can result in poor water quality; this can be useful for issuing preemptive closings at beaches without waiting for monitoring data to reveal an exceedance of water quality standards. For example, a sanitary survey may identify patterns of water currents that would be most likely to carry contaminated water to a beach. Sanitary surveys can also reveal techniques for shaping a beach so that Cladophora, a filamentous green alga that forms large mats and accumulates on beaches, is deposited in a confined area where it can be more easily removed. The mats smell noxious as they decay and also impact beachwater quality. They are associated with elevated fecal indicator bacteria counts—partly because they provide an environment where indicator bacteria can grow, and partly because they attract animals that deposit fecal material on the beach while feeding on the invertebrates and insects living in the mats. Sanitary survey data are now being used to develop beach redesign concept plans for the mitigation of identified pollution sources at 20 beaches on Lakes Michigan and Superior. Mitigation of pollution sources will reduce the number of beach advisories in Wisconsin.
User-friendly Tools to Implement Rapid Detection of Beach Conditions
The Great Lakes Restoration Initiative also funded projects to make it possible for more beach managers to use Nowcasting, a rapid method for predicting beach health conditions. Predictive models are useful because they allow advisories to be issued the day that bacteria levels are suspected to be high. In contrast, when advisories are issued on the basis of E. coli counts found using culture methods, they are issued the day after standards are exceeded because it generally takes 24 hours for culture results to be available. Moreover, many times, the culture results of samples taken the day a beach is placed under advisory reveal that the water quality was acceptable on the day of the advisory. The use of the Nowcast model should reduce the number of days that beaches are closed unnecessarily when water quality is good, as well as the number of days that beaches are left open when water quality is poor. Wisconsin has made Nowcasting a priority and worked to develop user-friendly tools to support it as a way to be effective in using the limited funds available for sampling while increasing the public notifications of beach condtions. These tools are linked to Wisconsin's Beach Health website, which, in turn is connected to the BeachCast mobile application developed by the Great Lakes Commission.
What Does Beachwater Monitoring Show?
In 2012, Wisconsin reported 193 coastal beaches, 59 (31%) of which were assigned a monitoring frequency of more than once a week and 58 (30%) once a week; 76 (39%) were not assigned a monitoring frequency. In 2012, 14% of all reported beach monitoring samples exceeded the state's daily maximum bacterial standard of 235 colonies/100 ml. The beaches with the highest percent exceedance rates of the daily maximum standard in 2012 were Wisconsin Point Beach 2 in Douglas County (64%); Bender Beach (48%) and South Shore Beach (43%) in Milwaukee County; Cedar Beach Road Beach (37%) and County Road D Boat Launch Beach (37%) in Ozaukee County; Kohler Andrae State Park North Picnic Beach (36%) and Kohler Andrae State Park South Picnic Beach (36%) in Sheboygan County; and Wisconsin Point Beach 3 in Douglas County (35%).
Douglas County had the highest exceedance rate of the daily maximum standard in 2012 (29%), followed by Ozaukee (26%), Milwaukee (23%), Kenosha (20%), Sheboygan (17%), Manitowoc (16%), Ashland (13%), Iron (11%), Brown (9%), Kewaunee (8%), Racine (7%), Bayfield (5%), and Door (4%). NRDC considers all reported samples individually (without averaging) when calculating the percent exceedance rates in this analysis. This includes duplicate samples and samples taken outside the official beach season, if any.
Wisconsin Percent of Samples Exceeding the State's Daily Maximum Bacterial Standard for 113 Beaches Reported 2008-2012*
* Please note that only samples from a common set of beaches monitored each year from 2008-2012 are included in the bar chart.
What Are Wisconsin's Sampling Practices?
Most Lake Michigan beaches are monitored from Memorial Day weekend through Labor Day weekend; monitoring at most Lake Superior beaches begins in late June. Local health departments conduct the water quality monitoring. Samples are taken in knee-deep water, 6 to 12 inches below the surface. Great Lakes beaches are assigned high, medium, and low priority for monitoring based on the potential for impacts from stormwater runoff, beach usage and population density, waterfowl loads, and the proximity of wastewater treatment outfalls and farms.
Additional sampling is required after heavy rain or other major pollution events, and beaches are resampled immediately when an advisory or closing is issued. States that monitor more frequently after an exceedance is found will tend to have higher percent exceedance rates and lower total closing/advisory days than they would if their sampling frequency did not increase after an exceedance was found.
How Many Beach Closings and Advisories Were Issued in 2012?
Total closing/advisory days for 551 events lasting six consecutive weeks or less increased 6% to 696 days in 2012 from 654 days in 2011. In prior years, there were 735 days in 2010, 401 days in 2009, and 883 days in 2008. In addition, there were no extended or permanent events in 2011. Extended events are those in effect more than six weeks but not more than 13 consecutive weeks; permanent events are in effect for more than 13 consecutive weeks. For the 551 events lasting six consecutive weeks or less, 89% (616) of closing/advisory days were due to monitoring that revealed elevated bacteria levels, 6% (40) were preemptive due to heavy rainfall, 5% (37) were preemptive due to weather that did not allow resampling to lift a contamination advisory already in place, and <1% (3) were preemptive based on the results of computer modeling.
How Does Wisconsin Determine When to Warn Visitors About Swimming?
Wisconsin issues both closings and advisories. A beachwater sample with 236 to 999 cfu/100 ml of E. coli generally results in an advisory, and a sample equal to or greater than 1,000 cfu/100 ml of E. coli generally results in a closing. The geometric mean standard of 126 cfu/100 ml for at least 5 samples collected over a 30-day period may also be used to make closing and advisory decisions at high-priority beaches. Some counties with longer beaches combine multiple samples along the beach before analyzing for bacteria; others take an average value of multiple samples analyzed separately and make closing and advisory decisions for the entire beach based on the composite or average results.
At the discretion of local beach managers, some beaches are closed or placed under advisory after rainfall exceeds a predetermined threshold, such as 1 inch of precipitation in a 24-hour period. In some locations preemptive advisories or closures are issued after sewer or stormwater overflows or incidences of reported illnesses.
Milwaukee uses predictive models in addition to monitoring to determine advisories for a few of its beaches. Ozaukee County uses a Nowcast model (developed using EPA's Virtual Beach software) at Upper Lake Park Beach, and in 2012 Racine County also received approval to use the Nowcast model. In those counties, an advisory may be based on evaluation of the results of the rapid detection methods. If a Nowcast indicates that an advisory is necessary and conditions change during the day, the public health official may analyze additional samples collected later in the day and change the status of the beach on the same day.
Wisconsin 2012 Monitoring Results and Closing/Advisory Days