A cement company says regular monitoring at an upstate New York landfill hasn’t shown signs of the pollutants an environmental group says are seeping into the Hudson River.

Stuart Guinther manages Lehigh Cement Co’s facility in the town of Catskill, 35 miles south of Albany. He said Friday the company was looking into the pollution claims, but he noted that groundwater has been tested regularly for more than a decade.

The environmental organization Riverkeeper filed notice Thursday that it intends to sue the Allentown, Pa.-based company over the issue.

Riverkeeper says its own tests show contaminants as caustic as household bleach are leaching into wetlands that feed the river, imperiling the environment and human health.