The border between Delaware and New Jersey is the Delaware River; it’s a most unusual border, because the boundary runs, not down the middle of the river, but at mean low water on the Jersey side of the river. In other words, the Delaware River is part of Delaware for this portion of its run.
The Delaware is a vital link in the US’s oil supply. There are refineries on both sides of the river in Delaware, New Jersey, and Pennsylvania, and tankers move up and down the river daily.
Delaware has for years, with sometimes stellar, sometimes spotty, success guarded its environment with the Coastal Zone Act.
New Jersey wants to poke a LNG terminal into Delaware waters. Delaware has determined that this would violate the Coastal Zone Act. So New Jersey is taking Delaware to court for the right to intrude in Delaware’s environment.
Meanwhile, one foot up river, New Jersey is opposing through inaction a plan to dredge the Delaware so it can accommodate even larger tankers. This is a project promoted by the U. S. Army Corps of Engineers, whose competence has been so lately demonstrated by events in New Orleans. Among its other objections, New Jersey claims that the dredging would endanger New Jersey’s environment because the spoils from the dredging would be deposited in New Jersey.
There’s actually a pretty nasty spat going on between New Jersey and Pennsylvania over this.
From my perspective in Delaware, it seems to me that New Jersey seems to have a bad case of NIMBY over the river, but a great willingness to play in others’ BYs.