Pollution and Water Quality

How do Our Waterways Get so polluted? 

All waterways in Anne Arundel County are “impaired” by pollutants washing into them from the surrounding land.  These pollutants make our waterways unsuitable for fishing and swimming at times. 

When it rains, any drop of water that does not evaporate or soak into the ground is called stormwater. Stormwater picks up pollutants such as sediment, lawn fertilizers, pesticides, pet waste, heavy metals, gas and oil,  and carries them to the nearest storm drain or stream.  As stormwater travels over impervious surfaces such as rooftops, roadways and parking lots, it picks up speed and causes erosion.


Loose soil particles called sediment cloud the water, preventing sunlight from reaching underwater grasses.  Without sunlight, these grasses cannot produce oxygen needed to support life.

When nutrients such as nitrogen and phosphorus from fertilizers, wastewater and septic tanks cause algae blooms.  These microscopic plants block sunlight from reaching underwater grasses.  When algae die, they sink to the bottom of rivers where they are decomposed by oxygen eating bacteria.

Excess sediment and nutrients in our waterways cause dead zones, areas where oxygen is so low that nothing can survive.

Every resident of Anne Arundel County can make a positive difference and do something to improve our watersheds … check out our Take Action page to find out how!

Who monitors our water quality?

Check out the links below to see the latestriver conditions in Anne Arundel County.

Local RiverKeepers and Watershed Organizations


Stormwater Runoff  

Sediment Pollution 101  

Nutrient Pollution 101