Photo by Carolyn Rumery Betz
UW Sea Grant Research
Bradford Beach on the Rebound 8/20/2008
By Carolyn Rumery Betz
Like many beaches on the Great Lakes, Bradford Beach in Milwaukee is frequently closed because of polluted water. The beach and swimming area suffer from high bacteria concentrations, making it unhealthy for swimming. Zebra mussels, mats of the algae Cladophora, and large flocks of sea gulls have also made the beach undesirable as a recreation destination. But Sue Black, director of the Milwaukee County Parks Department, has a vision.
“I can just see this whole area with people enjoying one of the best assets of Wisconsin,” Black said. “I see a renovated boathouse building and the area around it alive with rentals, cabanas, volleyball tournaments, bands, and food. Those are the things that will bring people back to the beach.”
In the same five years that Black has been parks director, Sandra McLellan also has been looking at Bradford Beach, but from a totally different perspective—that of a molecular biologist with the UW–Milwaukee’s Great Lakes WATER Institute. McLellan has made it her mission to determine where the bacteria are coming from that result in “Beach Closed” signs. This is not an easy task since the main culprit, E. coli, lives in the gut of all mammals—human and non-human.
Determining that the source is from humans, as opposed to other animals, allows resource managers to decide what course of action to take to improve water quality. “Bacteria from sewage is a very serious health risk, because we know that human sources cause human diseases,” says McLellan. “We don’t really know the health risk from other sources. But we do know that identifying the sources will tell us how to address them. For example, if we find sewage, we look for broken sewer pipes. If it is mostly from birds, we look for bird control measures.”
With funds from UW Sea Grant, students from McLellan’s lab have been sampling the numerous stormwater outfalls (structures that discharge water) in the area, including the seven that drain directly onto Bradford Beach. With every rainfall, stormwater carrying pollutants from nearby neighborhoods, roads, and parking lots drains directly into Lake Michigan via these outfalls. The outfall samples and water samples from Lake Michigan itself are analyzed in the lab by looking for specific sequences in the DNA.
McLellan’s work showed that most of the bacteria in the stormwater is of non-human origin. Based on these findings, a team of park managers, biologists, government agencies, and members of the general public agreed that on-site stormwater treatment was needed. Milwaukee County has contributed $1.5 million to the clean-up effort that is currently underway. Rain gardens are being constructed at each of the outfalls, allowing the stormwater to infiltrate into the sand instead of flowing over the beach to the lake. In addition, the beach is mechanically raked to aerate the sand, reducing the harm caused by high concentrations of bacteria from sea gull feces. Better garbage management and educational efforts will also be used to decrease the nuisance caused by the gulls.
“The beauty of the plan,” says Park Manager Sue Black, “is that it’s the science that is dictating the engineering at the end of the day. Without the baseline water quality data, none of this would have happened.” Project success will be measured by decreased E. coli counts, fewer beach closures, and flocks of people, not sea gulls, enjoying the beach each summer.