Authorities investigated a dark spot seen in El Dorado Lake Wednesday afternoon.


Authorities investigated a dark spot seen in El Dorado Lake Wednesday afternoon.

A pilot with Magellan Midstream Pipeline noticed the substance on the north side of the lake while doing a flyover and called authorities.

According to Sheriff Craig Murphy, it is not a petroleum based product and could be something natural.

The lake is still open for Memorial Day weekend and officials said it posed no danger to people. There also is no threat to drinking water.

Tests are being run on the water to determine what the substance was.