As tourists head to Michigan beaches this summer, some may be met with a “closed” sign.

Bacterial contamination has already shut down at least eight beaches around the state, according to the Michigan Department of Environment, Great Lakes and Energy. While some have since reopened, closures will likely plague other beaches throughout the summer.

A variety of pollutants are known to shutter beaches in Michigan and beyond. Sanitary and combined sewer overflows, groundwater runoff, failing septic systems and harmful algal blooms can all lead to beaches that are unsafe for swimming.

Here’s what some MSU experts have to say about beach contamination, its impact and what we can do about it.

Joan Rose, Homer Nowlin Endowed Chair in Water Research, director of the MSU Water Alliance, recipient of the Stockholm Water Prize and one of the world’s foremost water experts.
Contact: rosejo@msu.edu

“Our beaches in Michigan are a treasure, important to our health and economic well-being. Swimming in contaminated water is associated with an array of diseases, including respiratory, eye, ear and gastrointestinal infections. Our state has one of the best advanced water quality monitoring programs in the nation, which is a great partnership between the state, universities and public health. MiNet laboratories can track the fecal contamination of our beaches using microbial source tracking tools. This will allow us to restore problematic beaches by addressing the sources of the contamination.”

Phanikumar Mantha, professor of civil and environmental engineering, College of Engineering.
Contact: phani@msu.edu

“Several beaches in Michigan have closed due to high levels of E. coli bacteria. These closures typically follow heavy rainfall, which washes contaminants such as farm manure and sewage into the water, making it unsafe for swimming. Similar trends are observed in other Great Lakes states and at marine beaches. Rising temperatures, changing precipitation patterns, increased flooding and combined sewer overflows are expected to exacerbate these water quality issues. There is an urgent need for investments in improved water quality management and infrastructure, including reliable and timely warning systems, to address these recurring problems and protect public health.”

Ehsan Ghane, associate professor and extension specialist in agricultural water management and water quality, Department of Biosystems and Agricultural Engineering, College of Agriculture and Natural Resources.
Contact: ghane@msu.edu

“In freshwater bodies, too much phosphorus is the cause of toxin production from harmful algal blooms. These toxins disrupt the economy, coastal recreation and fishing. We need to find ways to reduce phosphorus from agricultural sources from getting into surface water bodies like Lake Erie.”

Xiaobo Tan, research foundation professor and Richard M. Hong Chair in Electrical Engineering, and director of the Smart Microsystems Lab in the Department of Electrical and Computer Engineering, College of Engineering.
Contact: xbtan@egr.msu.edu

“Given the frequency and scale of various contamination events, it is becoming increasingly important to deploy smart technologies, such as sensors, robots and AI, for monitoring drinking water sources and recreational beaches. These systems can help detect conditions of concern quickly and support early warning and decision-making.”

Anthony Kendall, assistant professor of earth and environmental sciences, College of Natural Science.
Contact:kendal30@msu.edu

“River systems can be particularly vulnerable to human pathogen contamination because water travels through them quickly with relatively little exposure to sunlight, which can help kill harmful microorganisms. Beach contamination potential is the highest near where these rivers empty into larger lakes or our Great Lakes. The risk is highest following high stream flow events, such as those produced by large rainstorms. Our research indicates the widespread presence of human pathogens in streams across Michigan. Furthermore, we identified the number and density of septic systems along those rivers as the most explanatory factor for that contamination.

“Properly designed, installed and maintained septic systems are highly effective at removing harmful pathogens from household and commercial wastewater. However, for a wide variety of reasons many septic systems are poorly maintained or malfunctioning — roughly 25% of systems are failing in these ways. Beyond that, there are still many places outside of sewer system service areas where illicit ’straight pipe’ connections directly contaminate waterways without any treatment. Proper maintenance, including regular inspection and pumping, is critical for keeping pathogens out of our waterways. Strong enforcement of existing health codes is also essential for deterring polluters. Currently, our state House and Senate are considering bills that would create a path forward for statewide health codes related to septic systems. These bills would improve water quality and promote the health and safety of our streams, rivers and lakes across Michigan.”