FAQ

There are four sources of air pollution in the Chesapeake Bay region. Stationary sources include power plants or manufacturing facilities. Mobile sources include cars, trucks and off-road vehicles; boats; airplanes; gas-powered lawn tools; and construction equipment. Agricultural sources include farm operations that emit gases, chemicals or particulate matter. Natural sources include lightning and dust storms.

Air pollution released into the Chesapeake Bay’s airshed will eventually fall back to the earth’s surface, where it could wind up in our rivers and streams. Airborne nitrogen, for example, is one of the largest sources of pollution affecting the Bay. Just over one-third of the nitrogen polluting the Bay comes from the air.

Plants and animals need nutrients to survive. But when too many nutrients enter rivers, streams and the Chesapeake Bay, they fuel the growth of algae blooms, which block sunlight from reaching underwater grasses create low-oxygen “dead zones” that rob the water of oxygen and suffocate marine life.

Sediment is made up of loose particles of sand, silt and clay. It is a natural part of the Chesapeake Bay, created by the weathering of rocks and soil. In excess amounts, sediment can cloud the waters of the Bay and its tributaries, blocking sunlight for underwater grasses, covering bottom habitats (such as oyster beds) as it settles and reducing water quality for fish and other aquatic species.

Depending on the source, some wastewater can contain nutrient or sediment pollution, or dissolved chemical contaminants. If left untreated, those pollutants can cause harm to waterways, wildlife or humans when released back into the environment.

Agriculture is the single largest source of nutrient and sediment pollution entering the Chesapeake Bay. But well-managed agricultural lands can offer the Bay watershed a number of benefits and services, including restored rivers and streams and valuable insect, bird and animal habitat.

Best management practices, or BMPs, are conservation practices that can reduce a farm’s nutrient and sediment pollution while maintaining a productive farming operation. Some common agricultural BMPs include conservation tillage, cover crops, forest buffers, streamside fencing and manure storage areas.

Atmospheric deposition is the process through which air pollution settles onto land or water.

Impervious surfaces are paved or hardened surfaces that do not allow water to pass through. Roads, rooftops, sidewalks, pools, patios and parking lots are all impervious surfaces.

Stormwater runoff is precipitation in an urban or suburban area that does not evaporate or soak into the ground but instead runs across the land and into the nearest waterway.

A dead zone is an area of the Chesapeake Bay that does not have enough dissolved oxygen to support aquatic life. Each summer, the Bay has a dead zone where fish, crabs and other animals cannot live because there is not enough oxygen in the water.

Nutrient and sediment pollution are the main causes of the Chesapeake Bay’s poor water clarity. Nutrients fuel the growth of water-clouding algae blooms, while particles of sediment can float in the water. Weather also plays a role in water clarity: rain storms wash dirt and pollutants into the Bay, muddying the water.