Coal ash could be contaminating drinking water in southeastern Wisconsin, according to a new report.
The report, published by environmental group Clean Wisconsin, looked at the levels of molybendum, an element present in coal ash, in about 1,000 drinking water wells in southeast Wisconsin. The group found that 23 percent of the wells had “high” levels of molybdenum and 22 percent had levels that were “very high” — high enough that they exceeded the Wisconsin Health Advisory Limit for the element.
According to the report, coal ash — a toxic waste product created by burning coal — is a likely culprit for the elevated levels of molybdenum, an element that occurs naturally in some legumes and grains but which has been linked to a gout-like disease if consumed in high quantities. In Wisconsin, 85 percent of the 1.8 million tons of coal ash produced by coal plants each year is reused, acting as a filler for spaces below roads and buildings to create level ground. According to the study, drinking water wells that were closer to coal ash reuse sites had a higher risk of having elevated molybdenum levels.
CREDIT: Clean Wisconsin
Molybdenum contamination has gotten so bad in some places that Wisconsin residents can’t drink their water. The report highlighted Yorkville Elementary school, which was found in 2013 to have drinking water levels of molybdenum that were 70 percent higher than the Environmental Protection Agency’s one-day exposure levels for children. Since that discovery, the school has had to rely on bottled water for its students and staff. That school, according to the report, was the site of a construction project that used 856 tons of coal ash in 2000. The report found that homes nearby the school also had elevated levels of molybdenum, as well as of boron and arsenic — two dangerous elements also present in coal ash.
“While this analysis doesn’t rule out contributions from other sources near Yorkville Elementary (unknown coal ash reuse and dumping sites, for example, or sewage sludge spread on farmland in the area), these results point strongly to the coal ash project at the school being a likely source of molybdenum in the area,” the report states.
The report notes, however, that the data it used on molybdenum levels in drinking water was limited. For private well data, researchers had to rely solely on homeowners who chose to get their water tested. That lack of data highlights the need for more groundwater testing, according to the report, especially in areas where coal ash has been used as a structural fill. The report also recommends that the state halt the practice of reusing coal ash as fillers for construction projects until more effective safeguards are put in place to prevent groundwater contamination.
“Wisconsin needs to revise its rules so that when coal ash is truly hazardous, as shown by an up-to-date and accurate leach test, it is regulated as hazardous,” the report states. “Coal ash should only be exempted from a ‘hazardous waste’ classification when tests determine that the ash will not leach toxic chemicals at levels sufficient to harm health and the environment.”
Wisconsin isn’t the only state that reuses coal ash, a practice that keeps some of the ash out of landfills or ponds but, as the Clean Wisconsin report shows, can also lead to contamination issues. Cities in multiple states have for many years used coal ash — which in addition to molybendum often contains such toxic heavy metals as lead, mercury, and arsenic — as a way of de-icing roads in the winter. That practice is troubling, according to some environmental and health groups, due to coal ash’s high levels of toxic elements. Coal can also be used in concrete, a practice that the EPA has dubbed safe.
This year, coal ash was thrust into the national spotlight after up to 82,000 tons of the substance spilled into the Dan River in North Carolina. But coal ash has been a major environmental concern for years: a 2013 study found that the waste product is responsible for the deaths of 900,000 fish every year in a lake in North Carolina, and a December 2008 spill in Tennessee flooded up to 300 acres of land and “resulted in a tremendous fish kill,” according to a local paper.