In 2018, Missouri-based School Sisters of Notre Dame requested that Ameren, one of Missouri’s largest utility companies, prepare a complete report on the company’s efforts to identify and reduce environmental and health hazards associated with past, present and future handling of coal combustion residuals (coal ash).

Ameren did not publicly disclose the impact that the company’s coal plants were having on Missouri’s ponds and groundwater, and they opted not to use protective clean closure practices that protected the groundwater from contamination. Initial testing of Ameren’s ash ponds revealed concentrations of arsenic, which is highly toxic, at levels more than 25 times higher than the federal drinking water standard. They also revealed levels of boron and sulfate, which Ameren itself had described as “the primary indicator parameters for coal ash leachate, many, many times higher than state drinking water and groundwater standards.”

Ameren’s response to these data was not to clean up the contamination, or even to study further the extent to which it had migrated from the ash ponds, but instead to hire a consultant to produce reports stating that contaminated groundwater is not a problem because humans are not drinking the groundwater at those locations and the contamination becomes diluted when it enters the Mississippi and Missouri Rivers.

The School Sisters of Notre Dame highlighted the considerable risks that the coal plants posed, arguing that Ameren did not have the right to pollute groundwater, as well as the Mississippi and Missouri Rivers, with impunity. A majority of Ameren shareholders approved their shareholder resolution, prompting Ameren to report on how it plans to address potential environmental and local health hazards from its disposal of coal ash waste.