Throughout the state, several lakeshores have temporarily closed, often due to E. coli contamination. Joan Rose, MSU Homer Nowlin Endowed Chair in Water Research and one of the world’s foremost water experts, says the source of some of that contamination is human waste from septic tanks.

Up-to-date septic tanks that are maintained work well in areas where they’re not too heavily concentrated. The problem is about 30% of Michigan homes have a septic system — the highest per-capita number in the U.S. Additionally, a 2015 study published by a team of MSU scientists tied septic systems to the presence of human fecal markers in watersheds across Michigan.

Of the 1.3 million to 1.4 million on-site wastewater treatment systems throughout the state, the Michigan Department of Environment, Great Lakes and Energy, or EGLE, estimates that about 330,000 are failing, sometimes without the homeowner’s knowledge. That means millions of gallons of raw sewage are released into Michigan’s groundwater every day, according to EGLE.

Rose, who’s also director of the MSU Water Alliance, is helping communities and state officials to find a solution. Her research has advised state Rep. Phil Skaggs in introducing bills that would create a statewide sanitary code regulating septic systems.

She’s also working with the Higgins Lake community, which is in the process of installing a septic tank effluent pump, or STEP, sewer system. Homes in the area would connect to the STEP system in place of their home systems. Rose and the MSU Water Alliance plan to test and monitor the lake for five years to collect data documenting the STEP system’s success.

Here, Rose answers questions about the current state of contamination from septic tanks, what’s being done and what’s at stake.

In 2015, you and other researchers published a study showing widespread contamination from septic tanks. Nine years later, what has changed? Has the situation improved or worsened?

We believe the situation has gotten worse. There are more individuals that live full-time in resort communities like Higgins Lake that used to be mostly seasonal. Those homes all have septic systems. We also know more about loading. If you have a huge loading of nutrients to a lake, like E. coli and pathogens, they could hang out for a month and affect water quality while people are on summer vacation. As more homes are being used as short-term rentals for large groups, that also affects water quality. The more people, the more poop, the more nutrients. But also, the more people, the higher the chance that one of them is sick with a pathogen such as a virus that goes into the septic tank and into the water. Contamination from septic systems is a long-term problem. It’s a problem we need to study and assess. It takes several years for communities to figure out how they’re going to improve their wastewater management systems and then to build and finance it. When we modernize our systems, that is an asset that improves the community for 50 to 100 years into the future. Lakes are also resilient. Once we get that infrastructure in place, we see water quality returning to a good state.

You mention that E. coli can be found in water from sewage runoff. What is E. coli, and how does it harm human and animal health?

All warm-blooded animals, including humans, have E. coli in their gut. It’s a natural part of the flora, and that’s why it’s a good indicator of fecal pollution and waterborne disease risk, because whenever you have poop, you have E. coli. E. coli can cause acute infections, like eye infections and gastrointestinal infections. But some types of E. coli can cause reactive arthritis, which can last for several years. E. coli 0157 is a very serious type of E. coli that can cause kidney damage and can even necessitate a kidney transplant down the road. Polluted waters can have other pathogens, like hepatitis A. That’s a classic example where you might get a little bit of diarrhea at first, but then it moves to the liver. There is a whole slew of pathogens associated with fecal pollution, like norovirus, shigella, salmonella and parasites like giardia. It’s not just the human population that can get sick. When you have harmful algal blooms, that releases toxins that can cause an array of respiratory symptoms, and puppies and other animals have tragically died from drinking the slimy water.

What are the barriers to homeowners replacing aging and failing septic systems?

Putting in a modern septic system could cost a homeowner $10,000 to $20,000, sometimes even $50,000. It’s a lot of money, and a lot of people just don’t have it. It’s not just in lake communities, it’s in small rural communities. We’re dealing with people on fixed incomes that don’t have those kind of resources to put into their water infrastructure.

And the cost is more after the housing developments are in place in areas that have too many septic systems. Most are basically a holding tank for sewage, and the water carrying the nutrients is discharged into the soil and away from the house. The treatment is in the soil. So, if there are too many septic tanks, the soil is saturated, and the nutrients move with the water. Even with modern systems, we’re not going to get the water quality we want if there are too many septic tanks in the area. That’s what has happened around our beautiful lakes.

What is the solution to having too many septic tanks?

I think we should hook homes up to a central wastewater treatment plant. When we’re building a modern wastewater system, it can provide energy and economic resources. The effluent could go to farming communities, and they could use the nutrients in place of fertilizer. When the ground is torn out to lay pipes, you could then lay a bike path or boardwalk for the community as you rebuild. Then, we’ve got a win-win situation. It’s a win for rural communities that may be nearby lakes. It preserves the lakes and adds value to the community.

The MSU Water Alliance is working with homeowners surrounding Higgins Lake to address contamination. Can you describe the potential impact?

Higgins Lake has been studied quite a bit by different researchers because of the impact of the nutrients, E. coli and other bacteria. They’ve put all the data together to show the deterioration of the lake over time. And now, as they start to build the new infrastructure, we’ll show on the flip side the improvement in water quality and the health of the lake. This is going to provide a roadmap to communities that want to replicate this effort.

When water quality deteriorates, it’s a gradual degradation. All of a sudden, you’ve got bad algal blooms year after year, whereas before you only had it once every five years or once every three years. Now you can’t use your beach. How long is it going to take to get back to clear water and beautiful beaches, without the risk of E. coli and getting sick? We want to document that so other communities can see how long it will take to improve their water quality if they make the same changes. Monitoring is expensive, but we need data. We need information for people to make good decisions and to show the return on our investments. We’ve got to prioritize data because without it, we’re just working blindly. When we have these hotspots where septic tanks are causing problems, we can give the community a roadmap for what they can do and how they can monitor their improvements.

What are the risks of failing to act?

If we have the same number of people around our lakes, we’re going to see continued degradation. As we keep building out, that will accelerate things. Climate change is also warming up temperatures and changing the dynamics of how pollution interacts with algae and other things in the system. More high rainfall events and flooding could cause more problems and more loading to the lake. We’re just going to see a time when we can’t use our lakes without running the risk of getting sick. It’s essential that we do something.