POLLUTION, in general

When many of us think of pollution, we envision toxic chemicals being dumped by factories and industries into a local waterway.
In reality, excess amounts of the nutrients nitrogen and phosphorus are the main pollutants affecting the Bay and its tributaries. Nutrients enter the Bay from a variety of human and natural sources, worsening water quality by fueling the growth of algae blooms. Air deposition is a major pathway for airborne nitrogen to reach the land and the water. Chemical contaminants and excess suspended sediment from erosion are also contributors to poor water quality.