What are some of the environmental problem caused by passaic river?

The river in its upper course flows in a highly circuitous route, meandering through the swamp lowlands between the ridge hills of rural and suburban northern New Jersey, draining much of the northern portion of the state through its tributaries. In its lower portion, it flows through the most urbanized and industrialized areas of the state, including along downtown Newark. The lower river suffered from severe pollution and industrial abandonment in the 20th century, but has begun to recover in recent decades.