The Army Corps of Engineers last month announced it would begin dredging the channel to a depth of 45 feet, despite lacking the approval of Delaware's environmental regulators. Delaware and New Jersey responded by filing suit in federal court to stop the project.

Both states and environmental activists argue that the project would violate environmental laws. They contend that the Army Corps has never fully assessed the impact of dredging 16 million cubic yards of muck from the river bottom. The Corps says its environmental impact studies support the 102-mile-long deepening.

There is also continued disagreement about the firmness of Gov. Rendell's pledge that Pennsylvania would become the dumping ground for the dredge spoils, which could be toxic. (Rendell reiterated in a letter to Gov. Corzine in May that Pennsylvania will accept the dredge materials after they have been "dewatered" at sites in New Jersey, a process that is part of the Army Corps' plan. But the agreement isn't legally binding on the Army Corps, sponsor of the project.)

This long-running debate really hasn't changed since Congress authorized the project in 1991. Pennsylvania sees the $379 million dredging plan as the key to keeping Philadelphia's port operations competitive. New Jersey and Delaware oppose it largely due to environmental concerns.

This Editorial Board has long supported the dredging project based on earlier projected economic benefits. But it would be useful, at this stage, to have a fresh independent assessment of the project's value and its environmental impact. It just so happens that such a review is on the way.

The Government Accountability Office is expected to issue a new analysis of the project's benefits and environmental impact early next year. The GAO has been one of the few independent brokers in this saga.

In 2002, the GAO criticized the Army Corps for vastly overstating the project's annual economic benefits, then pegged at $40 million per year. Since then, the Corps has estimated that the project would generate annual benefits of about $31 million.

The opposing sides in this debate don't agree on much, but they should be able to agree that the GAO doesn't have a dog in this hunt. In the past, the agency has undertaken a sober, fact-based review of the project's pros and cons.

Waiting for that review a few more months couldn't hurt, for a proposal that has been 18 years in the making. Given the GAO's last report, there's reason to wonder if the Army Corps decided to move ahead now because it wants to begin dredging before the new GAO report comes out.

A spokesman for Rendell said there's a danger of this project's being "studied to death." It's a valid concern. But given the serious objections by New Jersey and Delaware, and the imminent release of the GAO study, delaying the project a few more months is reasonable.