Types of water pollution

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Types of water pollution

What is the source of the pollution?


What types of pollution comes from those sources?

Keeping with a dual question theme, the source of water pollution is usually identified as either a point source or a non-point source problem.

Point source water pollution refers to specific, identifiable sources, such as sewage treatment plants or industrial plants, that directly discharge material into the water. Because they are easily identified, point source forms of water pollution are the easier of the two water pollution sources to regulate.

Non-point sources refers to the sources of water pollution that can not be traced to one definitive source. Agriculture run-off, for example, largely refers to the pesticides and fertilizers used in farming that get washed into local waterways such as rivers and lakes. However, since pesticides and fertilizers are also used by many household gardeners and local landscape services, determining or regulating the exact source of any river's pesticide and nutrient related pollution is problematic.

The types of pollution that come from both point sources and non-point sources often gets divided into four categories:


Toxic pollution:

Toxic pollution refers to both the organic or carbon based man-made compounds such as pesticides and PCBs, along with inorganic or heavy metals such as mercury and lead, that are used in ever day life and eventually end up in waterways. Toxic pollutants in the water represent a human health concern.

The Environmental Protection Agency (EPA), for example, discusses arsenic in drinking water as follows: "Arsenic is a semi-metal element in the periodic table...It enters drinking water supplies from natural deposits in the earth or from agricultural and industrial practices. Non-cancer effects can include thickening and discoloration of the skin, stomach pain, nausea, vomiting; diarrhea; numbness in hands and feet; partial paralysis; and blindness. Arsenic has been linked to cancer of the bladder, lungs, skin, kidney, nasal passages, liver, and prostate."

 Nutrient pollution:


Nutrient pollution refers primarily to the nutrients or fertilizers used in agriculture. While they represent necessary ingredients for plant growth, their overabundance in water causes excessive plant growth in water known as algal blooms. Algal blooms then lead to eutrophication (oxygen starved water) and ecosystem problems. The articles on Great Lakes Algal Blooms and the Mississippi River provide further examples of nutrient pollution.

Sediment pollution:

Sedimentation or sediment pollution refers to soil erosion that causes water quality problems. Excess soil in waterways such as rivers can cause ecosystem problems. Excessive sediment in western creeks and rivers, for example, has been linked to decreases in salmon spawning. Sediment containing toxins also creates additional health problems.

Bacterial pollution:

Bacterial pollution refers mainly to the human and animal waste bacteria that ends up in the water and causes health problems. The Food and Drug Administration (FDA) explained a recent outbreak of E. Coli poisoning related to spinach by saying, "Potential environmental risk factors for E.coli O157:H7 contamination at or near the field included the presence of wild pigs, the proximity of irrigation wells used to grow produce for ready-to-eat packaging, and surface waterways exposed to feces from cattle and wildlife."