Report: Climate extremes could pose danger of toxic contamination along Lake Michigan shoreline
High water levels along Lake Michigan could increase the risk of toxic contamination from industrial facilities along Wisconsin’s lakefront, according to a new report, as climate change is expected to bring more intense storms.
The report published this month by the Environmental Law and Policy Center identified a dozen areas along Lake Michigan in four states, including Wisconsin, that are vulnerable to flooding from high lake levels and heavy storms.
The group used federal data from the National Oceanic and Atmospheric Administration to identify the impacts of storm-related flooding during high lake levels. In Wisconsin, the report said sewage treatment plants at Two Rivers and Manitowoc, as well as Alliant Energy’s coal-fired power plant in Sheboygan, are at risk of flooding, which could send sewage or coal ash contamination in the lake.
“High waves exacerbated by climate change are putting increased pressure on the built environment of the coastline,” said Howard Learner, executive director of the Environmental Law and Policy Center. “The fact is, we need to rethink the shoreline built environment in light of higher water levels along Lake Michigan and the impact on shoreline industrial facilities.”
However, the operators of these facilities have pushed back against the group’s claims.
This monitoring identified statistically significant increases in levels of chemicals like boron, sulfate and fluoride in groundwater sampled from near-ash monitoring wells. ponds. Follow-up reports indicate that a closed coal ash landfill at the site is the likely source of the elevated levels.
“We are obligated to maintain and monitor this for at least the next 30 years,” McCarville said. “So if there were any changes in the environment, we would continue to monitor the groundwater around that and maintain the cap.”
She said the utility has no worries about heavy storms causing the ash ponds to overflow since they are already closed. Alliant recently announced that it is delaying the retirement of the facility until mid-2025.
The report also says the Two Rivers sewage treatment plant could become surrounded by water if the lake level reaches 587.3 feet, increasing the risk of erosion and contamination.
Dave Casebeer, superintendent of the Two Rivers sewage treatment plant, said the facility experienced overflows during torrential downpours. The plant was originally built in 1934, but Casebeer said it has undergone many upgrades.
Even so, he said flooding had not been an issue at the facility.
“At this point, I don’t care,” Casebeer said. “If the lake rises 5 feet, we’re going to be underwater.”
Casebeer said they had installed riprap, or rocky material, along the shoreline during records, but he said there was little else to do but relocate the installation .
Learner, of the Environmental Law and Policy Center, argued that it’s not that water levels will be up to 9 feet higher than current levels, but rather how far from shore storms will send waves from the Lake Michigan.
Plant officials also met with the US Army Corps of Engineers in May about degraded portions of the Corps South Pier in Manitowoc Harbor. Mike Jaeger, superintendent of the facility, said he was concerned the flooding could compromise the jetty and affect an adjacent tributary line, or sewer line, that brings sewage into the facility.
“If it ever jeopardizes that influent flow line, and it breaks or falls or something like that, then water won’t necessarily enter the plant,” Jaeger said. “It would then begin to enter the harbour.”
Even so, he doubted the lake level would reach the report’s projections of 585.6 feet, which could flood much of the facility. He said plant officials have been proactive in addressing high water levels.
Adam Bechle, coastal engineering outreach specialist at Wisconsin Sea Grant, said research conducted by Environment and Climate Change Canada has projected extreme higher and lower levels in climate change scenarios.
He said those projections estimate a lake level rise of about a foot by 2050. Research from Michigan Technological University has estimated increases of up to 17 inches on Lake Michigan by the mid-2050s. century.
Additionally, Bechle said preliminary flood maps developed by the Federal Emergency Management Agency show a 1% chance in any given year of the water level reaching 589 feet at the plant. Manitowoc wastewater treatment. At Two Rivers, there is a 1% chance in any given year that the water level will reach 585 feet.
The group’s report represents more extreme scenarios, Bechle said. The Environmental Law and Policy Center acknowledges having considered “more extreme conditions” in lake levels of 584 to 589 feet on Lake Michigan.
Even so, Bechle said it’s useful to assess what kind of flooding communities can tolerate, especially with critical infrastructure.
“There’s still a lot of uncertainty about what we’ll see with higher lake levels and larger storm surges and waves,” Bechle said. “So it’s really good to think about those kinds of scenarios.”