For many years, David Benzschawel, a civil engineer for the city of Madison, kept a large map in his office. It detailed dozens of closed landfills and historic dumps around the city. Benzschawel, who is now retired, checked the sites out himself and combed historic records to find out what was buried at each site.
At many of the sites, he found coal ash.
Several city parks and athletic fields were popular ash disposal sites, according to Benzschawel’s sleuthing. One dump was located on the banks of the Yahara River on the Isthmus and, according to Benzschawel’s record-keeping, was a repository for coal ash, including slag from the bottom of boilers and fly ash from smokestacks.
The legacy of coal ash disposal is readily apparent to city engineers and others who frequently run across the material when working on utility projects or preparing lots for construction.
Earlier this year, Madison removed 10,600 tons of fill, mostly coal ash and cinders, from a building site on the 700 block of East Washington Ave. that had recently been a car dealership. The material had become a concern because of its potential contaminants. It was hauled to a landfill.
One source of coal ash was the Blount Street power plant, operated by Madison Gas & Electric since 1902. The plant burned coal until 2011. Now it burns natural gas, wood waste and other materials.
Steve Kraus, a spokesman for the utility, said the plant did not generate the same volumes of ash as larger plants in southeastern Wisconsin. And because of the type of coal burned, the plant’s ash did not mix well as cement.
Still, he added, about 36 tons of ash from the plant was reused in the area after passage of the 1985 coal ash rule passed, part of it in the construction of Highway 12 between Middleton and Sauk City in the 1990s. The rest was landfilled.
But Kraus said it was common practice for many years before the 1985 beneficial reuse rule for MG & E and other industries, like Oscar Mayer, to legally dump ash in the many low, marshy areas on the Isthmus and elsewhere in the city.
“I’m sure that for parts of the Isthmus and anywhere there was a low spot, they threw in coal ash and garbage,” Kraus said.
Whether the ash has contaminated Madison’s water is unclear.
Chromium-6, an unregulated metal, has been detected at very low levels in 14 of Madison’s 22 municipal wells in testing that started in 2011. When ingested at high levels, it has been linked in studies to stomach cancer. It is found in coal ash, among other sources.
Joseph Grande, water quality manager for the Madison Water Utility, said the utility solicited input from the Wisconsin Geological and Natural History Survey. The Survey study analyzed rocks from the aquifer, found that they contained chromium and concluded that the rocks could be a potential natural source.
But the report did not address the potential for human sources, such as plating plants and buried coal ash.
Grande said wells on the Isthmus, where such contaminants are found in the upper levels of the aquifer, are cased with steel at depths down to 200 feet, below the area where contamination is likely occurring.
But Kenneth Bradbury, a hydrogeologist with the Survey who studies Madison’s aquifer, said the tons of buried coal ash are “not something you would completely rule out” as a potential source of the metal.
“It’s certainly plausible,” Bradbury said.
Grande said the utility is aware of the potential pollution from buried coal ash and has been testing for molybdenum in some wells. Those tests will be expanded to all wells next year, he said.
This story has been corrected. The U.S. Geological Survey’s analysis of rocks from the Madison aquifer found chromium, not molybdenum, as the story originally stated.
The nonprofit Wisconsin Center for Investigative Journalism (www.WisconsinWatch.org) collaborates with Wisconsin Public Radio, Wisconsin Public Television, other news media and the UW-Madison School of Journalism and Mass Communication. All works created, published, posted or disseminated by the Center do not necessarily reflect the views or opinions of UW-Madison or any of its affiliates.
Republish this article
This work is licensed under a Creative Commons Attribution-NoDerivatives 4.0 International License.
- Credit should be given, in this format: “By Dee J. Hall, Wisconsin Watch”
- If published online, you must include the links and link to wisconsinwatch.org
- If you share the story on social media, please mention @wisconsinwatch (Twitter, Facebook and Instagram)
- Don’t sell the story — it may not be marketed as an individual product.
- Don’t sell ads against the story. But you can publish it with pre-sold ads.
- Your website must include a prominent way to contact you.
- Additional elements that are packaged with our story must be labeled.
- Users can republish our photos, illustrations, graphics and multimedia elements ONLY with stories with which they originally appeared. You may not separate multimedia elements for standalone use.
- If we send you a request to change or remove Wisconsin Watch content from your site, you must agree to do so immediately.
For questions regarding republishing rules please contact Andy Hall, executive director, at ahall@wisconsinwatch.org
Deny, delay & disuade. ‘Check’. MOI?! More study required. Nothing to see here. Move along now.
The State of Wisconsin is enviromentally sick! Moreover, the air we breath is contaminated, the agricultural community has poisoned our cold water creeks and our rivers are polluted with sediment and nitrates, and whole ecosystem is in decline. It well known that the Departmens of Natural Resources is just a politcal orginization and is blind to what’s really going on in this state and I blame them (and the legislature(s) for the stat’s culture of lax enforcement in it’s favoring industry over the publics safety and our ailing ecosystem.