New York and Pennsylvania are among states that are being tasked with reducing pollution flowing downstream the the Chesapeake Bay but may not be doing enough.

In its midpoint assessment of a federal plan for reigning in the pollution, the Chesapeake Bay Foundation says headway is being made with underwater grasses and oysters making a come back and the Bay's oxygen dead zone shrinking, but some states are lagging in the effort to reduce urban and farm runoff.

The Susquehanna River in the Twin Tiers is one of the tributaries flowing into the Chesapeake Bay.

The Foundation says in spite of improvements in reducing pollution coming from sewage treatment plants in particularly falling short in dealing with the pollution that runs off from farms carrying deadly levels of phosphorous, nitrogen and sediment.

The federal plan calls for substantial reduction in pollution flowing into the watershed by 2025.