The Department of Environmental Conservation says it's monitoring a mysterious oil slick at a creek in Village of Piermont.

Neighbors say they recently noticed the oil slick that appeared in the water on Sparkill Creek.

They reported seeing work crews dumping some sort of liquid into the creek.

Longtime resident Laurie Lahey told News 12 on Sunday that there was a strong chemical odor inside her home.

Lahey said she and a neighbor first noticed the oil slick on Friday and that she could smell it for a half block in every direction.

Oil absorbing booms were placed in the water, which leads to the Hudson River.

The Piermont Fire Department responded to the reports and identified a construction site as the source of the issue.

Firefighters worked with the Rockland County Hazmat Team to contain and minimize the environmental impact.

In a statement, the department said in part, "DEC will continue to monitor and investigate the source site and creek to verify if further cleanup action is required to protect public health and the environment."