Groundwater supplies much of the United States with water. Over half of Americans rely on it, including nearly all rural residents. Groundwater is essential for millions of private well-owning individuals, businesses, and farmers.
However, heavy pumping in some areas has lowered water levels below what people can access. Just as concerning is groundwater quality, which faces constant threats from various sources.
In general, surface water is less dangerous than groundwater. But pollution can still seep through the soil and contaminate it. Most groundwater contamination results from human activities, whether intentional or accidental. Any procedure that emits waste or chemicals into the environment has the danger of contaminating groundwater.
In this article, we will explore the activities harming groundwater supplies.
Table of Contents
What Is Groundwater?
Groundwater exists below ground level, filling the spaces within rock and soil. Known as aquifers, these porous materials become saturated when they absorb precipitation that has percolated down from the surface over long periods.
The water table is the uppermost portion of the saturated zone of an aquifer. Unlike some perceptions, groundwater does not flow in underground rivers. Instead, it soaks the cavities and fractures within geologic materials similarly to how water is held in a sponge.
Aquifers enable groundwater to naturally discharge or be removed via pumping when present in enough volume. Groundwater moves gradually through aquifers, typically traveling between 3 to 25 inches daily. As a result, the same water may remain underground for hundreds or thousands of years.
In the United States, groundwater comprises approximately 40% of public water supply usage and 39% of agricultural water needs. Its slow movement allows for sustained usage, representing a critical water source.
How Important Is Groundwater?
Groundwater plays a hugely important role as a water source for humanity. Globally, it provides complete or partial drinking water for an estimated 50% of the population, over 3.5 billion people. Groundwater also accounts for 43% of irrigation water usage worldwide. Approximately 2.5 billion rely solely on groundwater to meet their daily water needs.
As the human population grows rapidly towards 11 billion by 2100, feeding so many people sustainably presents an immense challenge. We must learn to produce enough nutritious crops without degrading soil, water supplies, or the climate. Effectively managing groundwater reserves is central to the solution.
With responsible usage and replenishment practices, groundwater has tremendous potential to alleviate water scarcity issues. However, this requires a thorough scientific understanding of aquifers and wise policy decisions around groundwater governance. Sustainable groundwater stewardship ensures global food and water security for future generations.
Why Is Groundwater Contamination Dangerous?
Contaminated groundwater can lead to several problems, including poor drinking water quality, loss of water sources, degradation of surface waters, high cleanup costs, and expensive alternative water supplies. Ultimately, groundwater contamination poses serious risks to human, animal, and environmental health.
People and animals that rely on contaminated groundwater sources for drinking and other needs are at risk of waterborne illnesses. Toxic chemicals can spread among populations through groundwater. Unfortunately, those who depend the most on the water often cannot afford costly remediation efforts.
Drinking contaminated water poses severe health hazards. Diseases like cholera, dysentery, and hepatitis may result from septic system pollution entering wells.
Groundwater supplies can also be tainted by toxic chemical leakage, sometimes going undetected for long periods as contamination silently impacts communities. Only when issues like birth defects, cancer rates, or other symptoms increase is the full scope of the groundwater problems understood.
Industries tied to groundwater are additionally harmed. For example, contaminated waters can sicken fish populations or prematurely kill stocks, damaging fishing livelihoods.
The effects of past groundwater contamination at Marine Corps Base Camp Lejeune from 1953 to 1987 highlight these dangers. According to TorHoerman Law, volatile organic compounds and other toxins were found in two water treatment plants supplying the base.
As a result, the approximately one million people present there during that time may have been exposed.
People are now pursuing legal action through lawsuits such as the Camp Lejeune water contamination lawsuit against the guilty parties to address the serious health issues linked to the contaminated drinking water. Overall, groundwater pollution poses wide-ranging risks that require attention and remediation efforts.
Now that we understand the importance of groundwater and the dangers of contamination let’s explore potential sources of pollution.
Sources of Groundwater Contamination
Groundwater can become contaminated from both natural and human-caused sources. Some of the main potential sources include:
Natural Sources
Groundwater is not always contaminated due to human actions. Some contamination can arise from natural sources underground. Natural minerals, such as arsenic, iron, chlorides, sulfates, and fluoride, can dissolve into groundwater from surrounding rock and soil. Groundwater may also contain small particles of decaying organic material.
Over time, certain naturally occurring substances have the potential to build up in groundwater sources to levels that threaten human health if ingested. Other natural contaminants could make the water smell or taste bad or change its color.
Treatment is generally necessary before using groundwater contaminated naturally for domestic purposes like drinking, cooking, or bathing. Long-term groundwater consumption bearing high levels of naturally occurring contaminants without treatment could impact well-being.
Pesticide and Fertilizer Use
One of the biggest users of groundwater is agriculture. When animal waste, fertilizers, fungicides, pesticides, herbicides, and slurry are applied on land, contaminants like bacteria and nitrates can infiltrate subterranean water sources.
These have a serious impact on humans, animals, and plants that depend on water. Certain toxins can linger for months or years and have been connected to health problems in people, such as the common weed killer atrazine.
Waste from Sewers and Other Pipelines
When moving garbage, sewer lines can occasionally spill liquids into the groundwater and adjacent land. Heavy metals, nitrogen, bacteria, viruses, and inorganic salts are all present in sewage.
Similar problems can arise from poorly planned, situated, built, or maintained septic systems that leak pollutants, including household chemicals, bacteria, and viruses, into groundwater. Corrosive materials can cause leaks in pipelines that transport industrial chemicals and oil-brine.
Improper Disposal of Hazardous Waste
According to the same source, many people are unaware of how waste disposal affects groundwater quality. Groundwater is typically contaminated by the improper disposal of materials such as paints, motor oils, paints, paint thinners, disinfectants, and cooking and motor oils.
Additionally, industrial materials shouldn’t jeopardize drinking water by leaking down drains. Inappropriate chemical pouring down drains or improper medicine disposal can contaminate groundwater and pose a health risk to individuals.
Mining and Quarrying
Mining and quarrying release trapped pollutants into surrounding groundwater. Rain transports soluble chemicals like acid, iron, sulfates, and aluminum leached from rocks. Legacy issues involve toxins such as lead and arsenic used in 19th-century mining persisting in abandoned shafts.
Saltwater Contamination
Absorbents near coasts run the risk of being overpumped, which would reduce the amount of freshwater available for agriculture and drinking. Coastal towns that depend on wells are seriously threatened by saltwater contamination.
Landfills
Landfills bury garbage but must have protective bottom layers to prevent leachate contamination. Cracked or missing layers risk pollutants from garbage like paint, acid, car batteries, and cleaners infiltrating groundwater, posing health hazards.
Military Bases
Military locations concentrate harmful chemicals, including trichloroethylene (TCE) and per- and poly-fluoroalkyl substances (PFAS), causing concerns even today. Certain pollutants originating from these establishments harm adjacent groundwater resources. Cancer is one of the major health hazards associated with TCE and PFAS.
Atmospheric Contamination
After being discharged into the atmosphere, pollutants eventually return to Earth as precipitation and seep via surface water into groundwater. Acid rain seeps into groundwater supplies and becomes more acidic due to nitrates and sulfates from industry and power plants.
In summary, groundwater contamination presents serious threats to both human and environmental health. As many activities can pollute this vital water source in detectable and sometimes undetectable ways, it is important to investigate potential issues to ensure drinking water safety.
When contamination does occur, the impacts can be long-lasting and even lead to costly health problems and legal battles. Ongoing monitoring and stewardship of groundwater resources is needed to guarantee access to clean, pure water now and for future generations.
