One generally needn’t go to a dictionary to understand the meaning of the word pollutant, it’s something that doesn’t belong in the air or the water or wherever and may have harmful effects.
A first thought of a water pollutant is usually an industrial chemical spill. A good example of this was the leak from Freedom Industries chemical storage facility in West Virginia. The spill polluted the drinking water for hundreds of thousands of people. Ironically the chemical, methylcyclohexane methanol (MCHM), was used to “clean” coal.
Fossil fuels or there byproducts are also a major water pollutant. Duke Energy in North Carolina burns a lot of coal. The waste coal ash is stored in ponds. A breach of two ponds allowed a toxic brew of heavy metals to coat over 70 miles of the Dan River.
Right here in Arkansas an ExxonMobil oil pipeline flooded a quarter of a million gallons of a substance called diluted bitumen (dilbit.) This is a particularly toxic mixture of a solvent and tar.
The granddaddy of all spills, at least is recent history, was the blowout of a British Petroleum well in the Gulf. There, close to a quarter of a billion gallons of crude oil was released and fouled wetlands and beaches for hundreds of miles from Louisiana to Florida.
Another type of water pollutant is a set of chemical compounds which are referred to as Endocrine Disruptors. The substances can cause bizarre effects in fish and have the possibility to affect humans. Many male black bass in the Potomac River were found to actually be feminized males which were developing immature eggs. The source of the pollutant in this case was the metabolites of human pharmaceutical drugs coming from sewage treatment plants.
The total amount of these pollutants – fossil fuels, industrial chemicals, and wastes of all kinds – pale in comparison to the most common pollutant, nutrients. Nitrogen and Phosphorous, in the forms of their salts Nitrate and Phosphate are polluting fresh water around the globe. Even ocean estuaries are negatively impacted.
Nitrogen and phosphorous are referred to as limiting nutrients, plants don’t grow without them. Excessive amounts in both fresh and salt water cause excessive growth called algal blooms. After time the algae die off. As they decompose they consume oxygen in the water which can smother fish and other aquatic species.
A region near the mouth of the Mississippi River in the Gulf of Mexico is hypoxic, meaning extremely low in dissolved Oxygen. The size of this dead zone varies from year to year but has been as large as 10,000 square miles.
The Buffalo National River is now threatened with its own dead zone. Cargill, America’s largest privately held corporation supplies swine to an industrial hog farm in the watershed of the Buffalo. Up to 6,300 hogs are confined in two buildings just a stone’s throw from Big Creek which flows a scant 6 miles to the Buffalo.
Over 2 million gallons a year of hog feces, laden with Nitrogen and Phosphorous, are spread over a few hundred acres of hay fields. It is not a matter of if but when these nutrients begin to pollute America’s first national river.