The investigative work doesn’t end in the laboratory. McLellan routinely heads outside to confirm her findings. And often accompanying her on these scientific beachcombing trips are beach managers, city and county officials, and others who know the territory.
One success story is McLellan’s study of Bradford Beach, Milwaukee’s most frequently closed beach in 2004. She found that much of the E. coli came from seven stormwater outfalls scattered along the beach, as well as flocks of gulls that congregate along the shore (one gram of gull feces contains 340 million E. coli cells). These findings resulted in a joint effort with Milwaukee County to map the stormwater system and develop a proposal to relocate the outfalls away from Bradford Beach. “We have limited funds, so our work needs to be very focused,” said Gary Mick, director of Milwaukee County Environmental Services. “I don’t know how we would address the problems at Bradford Beach without Sandra’s ability to classify certain bacteria so we can tell where they’re coming from.”
One encouraging finding from McLellan’s research is that poor water quality at beaches doesn’t seem to be signaling that Lake Michigan as a whole is experiencing the same level of contamination. “We’ve found that most of the E. coli we detect in these beach areas usually comes from a very localized source,” she says. “That’s good news because it means there are management practices that can be put in place to fix some of these problems.”— Kathleen Schmitt