What is water pollution?
Water pollution is the release of substances into bodies of water that makes water unsafe for human use and disrupts aquatic ecosystems. Water pollution can be caused by a plethora of different contaminants, including toxic waste, petroleum, and disease-causing microorganisms.
What human activities cause water pollution?
Human activities that generate domestic sewage and toxic waste cause water pollution by contaminating water with disease-causing microorganisms and poisonous substances. Oil spills are another source of water pollution that have devastating impacts on surrounding ecosystems.
How does water pollution affect aquatic wildlife?
Sewage can promote algae growth, which can eventually result in eutrophic “dead zones” where aquatic life cannot survive because of a lack of oxygen. Microplastics are often found in marine wildlife and can become concentrated in humans who consume seafood because of biomagnification. Oil spills, such as the Deepwater Horizon oil spill in 2010, strand and kill many different marine species.
Is red tide caused by water pollution?
While some studies point to human activity as a catalyst for red tide, scientists are unsure about its cause. Red tide is a common term for harmful algal blooms that often poison or kill wildlife and humans who consume contaminated seafood. Red tides can severely impact ecosystems and local economies.
Groundwater pollution
Groundwater pollution caused by metals and industrial production waste.
If your water is contaminated (has unsafe levels of germs or chemicals), do not drink it and contact your health department for advice about how to make it safe to drink.
If your private well has harmful germs or chemicals in it, your neighbors’ water may also be unsafe to drink. This is because your well is likely connected to the same source of ground water (aquifer).
Public water is regulated but can sometimes get contaminated
The U.S. Environmental Protection Agency (EPA) regulates drinking water quality in public water systems and sets limits for germs and chemicals in water. However, sometimes unsafe levels of harmful germs and chemicals contaminate public drinking water. The germs and chemicals can get in the water at its source (for example, ground water or water from lakes or rivers) or while water is traveling through the distribution system, after the water treatment plant has already removed germs and chemicals from source water.
EPA requires water utilities to test for and address many germs and chemicals in their drinking water systems. Water utilities are required to tell customers about testing for contaminants and whether they found any unsafe levels of chemicals or germs in the water. Customers are notified through notices of violations and drinking water advisories. Water utilities must also provide their customers with an annual drinking water quality report called the Consumer Confidence Report.
Some people are more likely to get sick from germs and chemicals in water:
Infants
Young children
People who are pregnant
Older adults
People who have weakened immune systems, such as people living with HIV, getting chemotherapy treatment, or taking transplant medications
How water gets contaminated
Germs and chemicals can get in drinking water at the water’s source or in the distribution system after the water has already been treated. Harmful germs and chemicals can get in the water from many sources, including:
Fertilizers, pesticides, or other chemicals that have been applied to land near the water
Concentrated feeding operations (large industrial animal farms)
Manufacturing operations
Sewer overflows
Storm water
Wildlife
Rocks and soil that naturally have chemicals and minerals such as arsenic, radon, and uranium
Cracks in water pipes or other problems in the distribution system
What type of water is being impacted?
Groundwater pollution
Surface water pollution
Ocean water pollution
Crys.:
Groundwater gets polluted when contaminants—from pesticides and fertilizers to waste leached from landfills and septic systems—make their way into an aquifer, rendering it unsafe for human use. Ridding groundwater of contaminants can be difficult to impossible, as well as costly. Once polluted, an aquifer may be unusable for decades, or even thousands of years. Groundwater can also spread contamination far from the original polluting source as it seeps into streams, lakes, and oceans.
Crys.:
Surface water from freshwater sources (that is, from sources other than the ocean) accounts for more than 60 percent of the water delivered to American homes. But a significant pool of that water is in peril. According to the most recent surveys on national water quality from the U.S. Environmental Protection Agency, nearly half of our rivers and streams and more than one-third of our lakes are polluted and unfit for swimming, fishing, and drinking. Nutrient pollution, which includes nitrates and phosphates, is the leading type of contamination in these freshwater sources. While plants and animals need these nutrients to grow, they have become a major pollutant due to farm waste and fertilizer runoff. Municipal and industrial waste discharges contribute their fair share of toxins as well. There’s also all the random junk that industry and individuals dump directly into waterways.
Crys.:
Contaminants such as chemicals, nutrients, and heavy metals are carried from farms, factories, and cities by streams and rivers into our bays and estuaries; from there they travel out to sea. Meanwhile, marine debris—particularly plastic—is blown in by the wind or washed in via storm drains and sewers. Our seas are also sometimes spoiled by oil spills and leaks—big and small—and are consistently soaking up carbon pollution from the air. The ocean absorbs as much as a quarter of man-made carbon emissions.
