Read more in Coal Tattoo.

Read the DEP study.

CHARLESTON, W.Va. -- State regulators on Thursday issued a moratorium on new permits for the injection of coal slurry into underground mine voids, a practice that residents of several West Virginia coal counties have complained is polluting their drinking water.

Randy Huffman, secretary of the state Department of Environmental Protection, announced the moratorium at the same time he released a long-awaited DEP study of the issue mandated by lawmakers.

In a news release, Huffman emphasized that DEP's study did not find damage to surface or groundwater quality caused by coal slurry alone. But the agency's report made it clear that DEP lacked enough information to really provide much of an answer.

"Based on a review of the baseline data from the [underground injection control] and mining permits, there are insufficient surface and groundwater monitoring sample sites to determine effects from slurry injection on surface groundwater," the report said. "Most of the assessment sites lacked detailed information on mine pool conditions and adequate monitoring of the quantity and quality of the mine pool associated with the injection activities."

DEP officials did not indicate how long the moratorium would last, but the report and the agency's release spelled out some improvements for any future permit reviews.

Along with the moratorium, the DEP study recommended site-specific groundwater monitoring during the injection process, requiring a full baseline water survey for organic materials and heavy metals for any new permits, and monitoring wells within a half-mile of the mine pools receiving slurry injection.

Read more in Coal Tattoo.

Read the DEP study.

CHARLESTON, W.Va. -- State regulators on Thursday issued a moratorium on new permits for the injection of coal slurry into underground mine voids, a practice that residents of several West Virginia coal counties have complained is polluting their drinking water.

Randy Huffman, secretary of the state Department of Environmental Protection, announced the moratorium at the same time he released a long-awaited DEP study of the issue mandated by lawmakers.

In a news release, Huffman emphasized that DEP's study did not find damage to surface or groundwater quality caused by coal slurry alone. But the agency's report made it clear that DEP lacked enough information to really provide much of an answer.

"Based on a review of the baseline data from the [underground injection control] and mining permits, there are insufficient surface and groundwater monitoring sample sites to determine effects from slurry injection on surface groundwater," the report said. "Most of the assessment sites lacked detailed information on mine pool conditions and adequate monitoring of the quantity and quality of the mine pool associated with the injection activities."

DEP officials did not indicate how long the moratorium would last, but the report and the agency's release spelled out some improvements for any future permit reviews.

Along with the moratorium, the DEP study recommended site-specific groundwater monitoring during the injection process, requiring a full baseline water survey for organic materials and heavy metals for any new permits, and monitoring wells within a half-mile of the mine pools receiving slurry injection.

Slurry is a combination of solid and liquid waste produced when coal is cleaned and prepared for shipping to market. Coal operators often dispose of it in huge waste impoundments, but others have opted to pump it into mined-out areas of underground coal operations. DEP said 85 percent of the slurry in West Virginia goes to impoundments, and just 15 percent is pumped underground.

Residents in the Rawl area of Mingo County and the Prenter area of Boone County have sued mine operators, alleging that slurry injection made their drinking water wells unsafe. In response to complaints from those citizens, lawmakers in February 2007 gave DEP a year to study the possible water quality impacts of slurry injection.

After that study was completed, the state Department of Health and Human Resources was to perform a follow-up review to determine if slurry pollution was harming human health.

DEP is more than two years late in completing its part of the study, and in the report released Thursday agency officials said that one year was "not sufficient" time to complete a "highly technical and complex" study.

But the DEP study also outlines a variety of reasons that agency officials were not able to fully explain the possible water quality impacts of slurry injection.

For example, some sampling indicated that coal slurry's chemical composition was similar to coal. "This similarity creates difficulty in isolating water quality impacts due solely to the injection of coal slurry in underground mines," the DEP report said.

"Many of the abandoned underground mines included in the study are located in areas adjacent to mining activities," the study said. "These coal mining activities have water quality impacts that would look similar to impacts from slurry injection. Therefore, it is difficult to differentiate causes of these impacts."

Reach Ken Ward Jr. at kw...@wvgazette.com or 304-348-1702.