INDIANAPOLIS — Near many of Indiana’s coal-fired power plants, the ground water is a toxic mix of arsenic, boron, cobalt, lead, molybdenum, radium and thallium, new Environmental Protection Agency data reveal.

Recently released reports, using data collected for the first time, raises questions about groundwater safety and is likely to prompt a debate about how the state with the nation’s highest concentration of coal ash pits will react.

How far such pollutants have migrated from the power plants that created them, and the possible effects on neighboring residential wells have not been determined.

Indiana’s utility companies stress that the results are from wells directly next to the pits, and the companies have no reason to believe that their polluting pits present a threat to the state’s water ways or public health.

“What I would want to know from a consumer perspective, is that this data does not reflect groundwater conditions farther away where many of our plant neighbors are located,” said Angeline Protogere, spokeswoman for Duke Energy in Indiana. “We don’t want people to panic and think this data is more than it is.”

But they and environmental health advocates agree that the new data calls for more testing to determine the extent of the contamination and its potential dangers.

And, as regulators prepare for more study, some utilities already plan to close the controversial ash pits. That has some environmental advocates questioning whether capping the pits is an adequate remedy, as some utilities claim, or whether the material should be removed and sealed in pits lined with concrete or some other impermeable material.

“To sum up, we have seen enough to confirm that any place you leave coal ash with no liner underneath it,” said Indra Frank, the Hoosier Environmental Council’s environmental health director, “then the groundwater underneath gets contaminated.”

Groundwater at as many as 14 power plants around the state — from IPL’s Harding Street station in Indianapolis up to NIPSCO’s Michigan City station and down to Duke’s Gallagher station in New Albany — was found to have dangerous levels of pollution, according to an analysis by the Indianapolis Star.

A snapshot of numbers from Indiana reveals levels of arsenic more than 45 times the U.S. Safe Drinking Water Act standard at IPL’s Harding Street station. Elsewhere in the state, levels of lead reached nearly three times the accepted guideline and levels of radium as many as eight times what is deemed safe for drinking water.

The contaminants present and their levels vary among the sites, but many of the contaminants are known to be carcinogenic, toxic to the nervous system and damaging to the heart, lungs and reproductive systems.