Water Pollution - Point and Nonpoint Sources
Water Pollution - Point and Nonpoint Sources
Water Pollution - Point and Nonpoint Sources
AND OTHER CAUSES OF WATER POLLUTION A List of Water Pollution Causes Hey, we saw recently on the Made-Up Facts Channel that the human body is:
PARTS IN THIS SERIES 1. Water Pollution Facts 2. Water Pollution Causes 3. Water Pollution Effects 4. Water Pollution Solutions Our next series, Ocean Pollution, will appear in future issues of Grinning Planet. Sign up for our mailing list so don't miss it!
81% water; 18% carbon, calcium and nitrogen compounds; and 1% odor molecules.
After collecting so many causes of water pollution for this article, we think that last 1% might be from water too! In this articlepart 2 of a serieswe list the top water pollution causes. Some will surprise you!
Pesticides that get applied to farm fields and roadsidesand homeowners' lawnsrun off into local streams and rivers or drain down into groundwater, contaminating the fresh water that fish swim in and the water we humans drink. It's tempting to think this is mostly a farming problem, but on a square-foot basis, homeowners apply even more chemicals to their lawns than farmers do to their fields! Still, farming is a big contributor to this problem. In the midwestern United States, a region that is highly dependent on groundwater, water utilities spend $400 million each year to treat water for just one chemicalthe pesticide Atrazine.
extraction operations for oil and gas can also contaminate coastal waters and groundwater. As for gasoline and gas additives, leaking storage tanks are a big problem. The US Environmental Protection Agency (EPA) estimates that about 100,000 gasoline storage tanks are leaking chemicals into groundwater. In Santa Monica, California, wells supplying half the city's water have been closed because of dangerously high levels of the gasoline additive MTBE.
The mining process exposes heavy metals and sulfur compounds that were previously locked away in the earth. Rainwater leaches these compounds out of the exposed earth, resulting in "acid mine drainage" and heavy metal pollution that can continue long after the mining operations have ceased. Similarly, the action of rainwater on piles of mining waste (tailings) transfers pollution to freshwater supplies. In the case of gold mining, cyanide is intentionally poured on piles of mined rock (a leach heap) to chemically extract the gold from the ore. Some of the cyanide ultimately finds its way into nearby water. Huge pools of mining waste "slurry" are often stored behind containment dams. If a dam leaks or bursts, water pollution is guaranteed.
MINING A TOP CAUSE OF WATER POLLUTION The Iron Mountain mine in California, USA has been closed since 1963 but continues to drain sulfuric acid and heavy metals (such as cadmium and zinc) into the Sacramento River. The river's bright orange water is completely devoid of life and has a pH of -3, which is 10,000 times more acidic than battery acid. Experts say the pollution may continue for another 3,000 years. Source: Worldwatch Institute / Earthworks
Perhaps the worst offense in the category of mining vs. water pollution causes: Mining companies in developing countries sometimes dump mining waste directly into rivers or other bodies of water as a method of disposal. Developed countries are not immune from such insanity: The US government in 2003 reclassified mining waste from mountaintop removal (a type of coal mining) so it could be dumped directly into valleys, burying streams altogether.
When forests are "clear cut," the root systems that previously held soil in place die and sediment is free to run off into nearby streams, rivers, and lakes. Thus, not only does clearcutting have serious effects on plant and animal biodiversity in the forest, the increased amount of sediment running off the land into nearby bodies of water seriously affects fish and other aquatic life. Poor farming practices that leave soil exposed to the elements also contribute to sediment pollution in water.
the normal operation of nuclear power stations (i.e. from the nuclear waste); the mining and refining of uranium and thorium; and the use of radioactive materials in industrial, medical, and scientific processes.
In the oceans, the biggest sources of man-made radioactive elements are the nuclear fuel reprocessing plants at La Hague in France and at Sellafield in the UK. Discharges from these facilities have resulted in the widespread contamination of large marine areas. Radioactive elements traceable to reprocessing can be found in seaweed as far away as the western coast of Greenland. Source: Greenpeace, et al
Scientists are finding fragrance molecules inside fish tissues. Ingredients from birth control pills are thought to be causing gender-bending hormonal effects in frogs and fish. The chemical nonylphenol, a remnant of detergent, is known to disrupt fish reproduction and growth.
advisories or are closed each year. It's clear that sewage is part of the problem, even in what is supposedly the most advanced country in the world.
Figure 1. Sources of pollution that resulted in beach advisories and closings
[Source: US EPA]
WATER POLLUTION BY DEATH Even the dead are a cause of water pollution. In India, if a deceased person's family cannot afford a funeral they may immerse the ashes of their loved one in the sacred Ganges Riveror they may put the corpse itself in the river.
In a well publicized case in 2000, at least 17 whales were stranded on beaches in the northern Bahama Islands, with the likely cause being US Navy vessels operating midfrequency sonar systems nearby.
Poorly designed landfills Road deicing salts Hazardous waste sites Pet feces and wild animal droppings
Cruise ships Well, that's all for this segment, but we hope you'll row on to Part 3Water Pollution Effects on wildlife and humans.
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