Crews were on the scene of what appeared to be an oil slick in the Lehigh River Saturday, but turned out to be a harmless liquid.

Allentown Fire Department Capt. John Christopher said officials were alerted of the slick around 3:15 p.m and a command post was soon set up at Adam's Island

According to Christopher, crews placed booms in the river to soak up the liquid.

On Sunday, Christopher said the liquid was a biodegradable, non-toxic hydraulic fluid.

He said they tracked the source of the spill to heavy construction equipment on the Route 22 bridge. A hydraulic line on a piece of equipment broke causing the fluid to spill.

He said no charges are expected since the liquid did not harm the environment. However, Christopher said the construction company may have to pay for some of the cleanup expenses.