CWTA - Connecticut Water Trails and Water Pollution - Causes Of Water Pollution



Connecticut Water Trails Association

Table Of Contents

Connecticut Water Trails

Basic Concepts

Paddling Resources

Water Trails & Water Pollution

Causes Of Water Pollution

Types Of Water Pollution

Connecticut Water Trails Program

Water Trails & Water Pollution

Causes Of Water Pollution - Atmospheric Deposition

Atmospheric deposition is the pollution of water caused by air pollution.

In the atmosphere, water particles mix with carbon dioxide sulfur dioxide and nitrogen oxides, this forms a weak acid.
Air pollution means that water vapor absorbs more of these gases and becomes even more acidic.
When it rains the water is polluted with these gases, this is called acid rain.
When acid rain pollutes marine habitats such as rivers and lakes, aquatic life is harmed.

Surprisingly enough, air pollution contributes substantially to water pollution. Pollutants like mercury, sulfur dioxide, nitric oxides, and ammonia deposit out of the air and then cause problems like mercury contamination in fish, acidification of lakes, and eutrophication (nutrient pollution). Most of the air pollution that affects water comes from coal-fired power plants and the tailpipes of our vehicles, though some also comes from industrial emissions.

Air Pollution

Acid Rain

Acid rain is caused by burning fossil fuels that are released into the atmosphere from impurities found in burning ores and coal. The chemicals that create acid rain are sulfur dioxide and nitrogen dioxide.

Acid rain forms high in the clouds in a gaseous form. These gases stay in the atmosphere until they come in contact with rain, which dissolves the gasses. A mild solution of sulfuric acid and nitric acid is formed. These drops fall to the earth and get into our water table beneath the surface. From there they are collected into streams, rivers, and lakes that eventually will lead to the ocean.

Rain isn't the only form of acidity that falls to the earth. Acidity also falls through dry deposition as gases and dry particles. The wind blows the acid particles into cars, homes, trees, and buildings. The acid deposition is then washed from the surface by rain. The runoff adds to the acid, already in the rain, and adds to the acidity in the water.