Efforts to clean up the lower stretch of the Passaic River are getting a $150 million boost, thanks to a new settlement between the federal government and 85 likely polluters. This stretch of the river, running through Newark and nearby towns, is coated with a lining of toxic mud, tainted by decades and decades of chemical dumping. Getting it cleaned up will be difficult – and expensive. At roughly $1.8 billion, the Passaic River is estimated to be the costliest project currently facing the EPA’s Superfund program. That makes the settlement a small, but welcome, step forward.