By Mike DeNardo

PHILADELPHIA (CBS) –– Salt, it’s everywhere you look these days, on the roads and on the sidewalks. Officials say it’s a necessary evil, as crews work to keep snowy roads open.

It’s a matter of priorities. While transportation officials weigh public safety against environmental concerns from salt runoff, keeping the roads safe and passable is paramount, says Steve Schapiro, a spokesman for the New Jersey Department of Transportation.

READ MORE: 6 Dead, 30 Wounded In Shooting At Chicago-Area July 4 Parade; Person Of Interest In Custody: Police

“Our primary responsibility in the winter of course is ensuring public safety by keeping those interstate highways and the state highways clear of snow and ice,” he said.

ALSO READ: Cold Weather Crippling Car Batteries, What You Can Do To Avoid Trouble

READ MORE: Fourth Of July Parade, Concert, And Fireworks Take Over Philadelphia

Schapiro says spreading a calcium chloride brine on roads first, allows crews to use less rock salt after the snow falls. Even so, having all of that leftover salt on the road surfaces now, prepares them for the next snowfall.

“Having some residual salt on the roads gives us a head start,” he said.

MORE NEWS: For Some, Fourth Of July Traditions Down Jersey Shore Date Back To 1960's

For a nor’easter that could arrive Thursday.