Rotting grass cuttings, leaves and other debris may be leaching manganese.
Public health officials have identified a potential new threat to Long Island's groundwater from an unlikely source: rotting grass cuttings, leaves and other natural debris.
The state Department of Environmental Conservation recently reported that facilities that process "vegetative waste," such as commercial composting operations, appear to be causing elevated levels of manganese in groundwater.
"It definitely is a new universe of stuff to evaluate and manage," said Walter Dawydiak, acting director of environmental quality for Suffolk County's Department of Health Services. "These are not numbers typically seen in groundwater samples."