By: Jake Gallagher | August 27, 2023

This site provides a lot of useful info (I certainly hope) about household water and products to improve your water. What you might not know much about though is overall water quality in the US.

If you’re reading this while enjoying a refreshing drink of clean water, you might be under the impression that water contamination is an issue…elsewhere. While a vast majority of Americans do have access to clean water, toxins such as arsenic, copper, and lead continue to be an issue throughout the US.

To help you understand some of the lingo—and the high stakes—I’ve put together this overview of water pollution, its causes, the methods used to assess water quality, and the measures you can take to ensure the safety of your home’s water supply.

Let’s dip into the deep end of water quality in the US.

What Is Water Pollution?

Water pollution occurs when contaminants enter the water system. The water quality degrades due to the presence of these toxic substances. They can just make it taste or smell awful or they can make it dangerous to drink or bathe in.

According to the Safe Drinking Water Act of 1974, a contaminant is any physical, chemical, biological, or radioactive substance or material in water. Therefore, the legislation generally defines contaminants as any substance other than water molecules—H2O—including chemicals, pathogens, garbage, excess nutrients, and heavy metals.

The Environmental Protection Agency (EPA) has a comprehensive list of drinking water contaminants known as the Contaminant Candidate List (CCL)

The general categories of drinking water contaminants and examples of each are as follows:

  • Chemical contaminants. These contaminants can be of natural or anthropogenic origin. Nitrogen, bleach, salts, pesticides, toxins generated by microorganisms, and human or animal medications are examples of chemical contaminants. So your fabric softener and your Prozac, basically.
  • Physical contaminants. These contaminants have the highest impact on the appearance or other physical qualities of water. Soil or organic debris floating in the water of lakes, rivers, and streams as a result of soil erosion are examples of physical contaminants.
  • Radiological contaminants. These are chemical elements with an uneven number of protons and neutrons that produce unstable atoms capable of emitting ionizing radiation. Cesium, plutonium, and uranium are examples of radiological contaminants. Always dispose of your uranium responsibly.
  • Biological contaminants. Organisms found in water are considered biological contaminants. You may have heard of microorganisms or microbiological contaminants. Bacteria, viruses, protozoa, and parasites are all examples of biological or microbiological contaminants. Remember when you adopted your dog and it took months to rid her of Giardia? That illness falls into this category. And humans can get Giardia too!
  • Heavy metals. Metals like zinc and copper are often used to stimulate growth in cattle and poultry. These metals and others, such as lead, chromium, and arsenic, are excreted in their fecal matter and end up in soil, from where it flows into rivers and streams as runoff. Drinking water laced with heavy metals won’t suddenly make you a fan of Metallica, especially the late 90s albums, but they can damage the kidneys, the nervous system, and the cardiovascular system.

Types of Water Pollution

The classification of water pollution depends on where it comes from and where it goes. Below are some of the most prevalent forms of water pollution.

Surface water pollution

A water body that occurs naturally on the earth’s surface is referred to as surface water. Examples include lagoons, lakes, seas, and rivers. Surface water pollution occurs as a result of contaminants dissolving in or mixing with the water in these bodies. It can be unintentional, such as oil spills in the ocean, or deliberate, such as industrial corporations dumping waste into rivers or seas. Sadly, neither example is unheard of.

Groundwater pollution

Aquifers are underground reservoirs from which groundwater originates. Agriculture is a major source of water pollution that affects groundwater resources. Fertilizers and pesticides applied to fields and farmlands are easily absorbed into the soil and can also be spread by rainfall runoff.

Waste from landfills and septic systems can also seep into the ground and contaminate groundwater. Once these dangerous chemicals and substances reach groundwater, they are often harvested from wells or boreholes and used for drinking water and other human purposes. When water is drawn from contaminated groundwater resources, it is crucial that the water be analyzed and treated to ensure it is suitable for human consumption and other uses.

Oxygen depletion pollution

Oxygen depletion is another type of water contamination. Each year, substantial quantities of biodegradable materials are discharged into surface waters. (Biodegradation doesn’t mean a substance disappears, it means it’s broken down and redistributed.) High concentrations of these materials often decrease the water’s oxygen supply. When oxygen levels are too low, all species dependent on oxygen for respiration perish, and anaerobic organisms (those that don’t need oxygen) thrive.

As numerous anaerobic species create ammonia, sulfides, and other deadly chemicals, this can make water even more hazardous for aquatic life and humans who rely on surface water for drinking.

Thermal pollution

Rapid temperature fluctuations in a natural body of water can cause thermal pollution. This contamination is typically a result of discharges from industrial facilities or other human activities. Thermal pollution can disturb natural processes and cause aquatic organisms to experience stress, sickness, or even death.

Thermal pollution usually affects oxygen levels in water. The influx of warmer water into rivers and lakes causes a decrease in oxygen levels, impacting both humans and aquatic life. Warmer water promotes algae bloom (specifically blue green algae), which absorbs sunlight and contributes to additional warming. As is the case with agricultural runoff and untreated sewage, these impacts are frequently exacerbated if the discharge water is rich in nutrients.

Even a small amount of toxins present in these water sources can compromise drinking water quality, necessitating a thorough evaluation of water from thermally polluted regions before implementing treatment techniques.

Microbiological pollution

Microbiological pollution is a natural form of water contamination that is caused by microorganisms such as protozoa, viruses, and bacteria that occur naturally. Some of these microbes can cause illnesses, such as cholera and bilharzia, if they are present in water. 

In regions where people consume untreated tap water, the impacts of microbiological contamination are prevalent. Despite the rarity of these diseases in the US, it is vital that community water systems, especially in rural America, are well treated to avoid contaminated drinking water.

Suspended matter

Some pollutants are too large to mix with water molecules; therefore, they cannot be dissolved in water. Cans, straws, and other bulky plastic materials are among them. They cause oxygen depletion pollution by forming a layer on the water’s surface when suspended.

Riverbeds and lake beds can also get contaminated with hazardous chemicals from some of this particle debris. You’ve probably observed the growing concern about the presence of microplastics in human drinking water—and even human blood.

Intake of microplastics in community water systems is possible in a variety of ways, including surface runoff (such as after a heavy downpour), wastewater effluent (both treated and untreated), combined sewage overflows, industrial effluent, degraded plastic trash, and atmospheric deposition.

The two most common sources of microplastic pollution are surface runoff and wastewater effluent, although more precise data is needed to identify the exact amounts and types of plastics coming from each. It’s also suggested that microplastics in drinking water originate from the plastic used to package bottled water.

Although there is little research to reach definitive conclusions on the toxicity of plastic particles, particularly nanoparticles, there is no credible evidence that this is a cause for worry—yet. Liver inflammation was one effect found in rat and mouse toxicology investigations. However, the reliability and applicability of these few studies are in question since the results were published at extremely high concentrations that would never be found in drinking water.

What Are the Main Causes of Water Pollution?

Water contamination can be caused by both natural and man-made factors. The most prevalent causes of water contamination, however, are man made. They include the following:

Agricultural run-off

Agriculture is one of the most significant contributors to water contamination in the country. Large volumes of water and waste from crop production and animals are released by agricultural activities, generating both water shortages and severe contamination in adjacent regions. Here are the primary sources of such pollution:

  • Excess nutrients, such as nitrates found in agricultural fertilizer, can limit aquatic plant development and kill fish. They can also be dangerous to newborns if present in drinking water.
  • During rainstorms, animal excrement and agricultural chemicals are carried away. Waterborne illnesses, including cholera, typhoid, and dysentery, can make their way into rivers and water sources.
  • Antibiotics and hormones are often given to cattle and then excreted into the environment. Hormones can be active for months after excretion, moving for kilometers downstream and interfering with fish breeding. Antibiotics found in community water systems can contribute to the spread of antibiotic-resistant bacteria and viruses.
  • Manure contains sodium, potassium, calcium, sulfate, bicarbonate, nitrate, and other salts that can enter streams, increasing salinity, changing ecosystems, and rendering drinking water unsafe.

Nonpoint water pollution

Rain and melting snow carry contaminants with them as they move over and through the ground. Waterways further downstream can be contaminated by runoff from farms, cities, suburban and rural residences, parking lots, and woods. Chemicals used to kill weeds on lawns, as well as road salt used to melt ice on roadways, can end up in water. Stormwater runoff can clog navigable streams and contaminate drinking water sources.

Leakage from subterranean storage and piping

Leaks in underground storage facilities and pipelines are a possibility when transporting coal and other industrial and petroleum products. Spills can result from prolonged use and deterioration. Accidental leaking can also happen at any point in the transportation process, resulting in soil and water contamination.

Leaking sewers

Sewer overflows aren’t only gross, they are also a major cause of water contamination. When a sewer overflows, the contents can enter water sources before they are treated. The discharge can end up in seas, rivers, and estuaries, harming human health and fishing communities, and causing beach closures. Improperly maintained septic systems can also cause pollution in coastal areas.

Vehicle leakages and emissions

Motor vehicle emissions in the atmosphere can settle or make their way to surface water and groundwater through rain. Oil leaks from parked vehicles can run off. Automotive oil, visible as a colorful sheen in puddles, can become a nonpoint source contaminant that drains into streams, lakes, rivers, and other water reservoirs.

Radioactive materials

Radioactive pollution in the US may not be as common as it is in Japan. However, the Indian Point nuclear power facility on New York’s Hudson River sometimes emits radioactive water with “acceptable” levels of contamination, according to regulatory rules. Over 100 distinct isotopes, including Iodine-131, Strontium-89, and Strontium-90, are emitted in trace quantities into the water and air. These, like contaminants from agriculture, industry, runoff, cars, sewage, and other sources in the United States, can contaminate water systems.

Industrial activity

Wastewater from factories often contaminates drinking water. Water is affected by toxic chemicals in many ways, including an increase in mineral content, a shift in color, and a rise in temperature. Mercury, asbestos, nitrates, and lead are just some of the pollutants that often originate from factories. You might recognize some of these major causes of industrial water pollution:

  • Burning of fossil fuels. The burning of fossil fuels results in the release of ash (containing harmful compounds) that combines with water vapor to form acid rain, which then finds its way to water systems.
  • Foundries. Metals and other particles from foundries can be released into the air directly, where they will ultimately make their way to water.
  • Mining. Crushing rock, mining coal and minerals, and other mining related activities produce toxic chemicals and poisons, such as sulfides from rocks and metal debris, that contaminate water.
  • Treatment of wastewater. The treatment of industrial, commercial, and residential wastewater is designed to eliminate the majority of sediments, pathogens, and organic substances. But it has to go somewhere. It is not always the case that the effluent discharged into local waterways is devoid of bacteria, viruses, silt, metals, and other contaminants.

Global warming

Water contamination is another severe consequence of global warming. Some aquatic organisms will perish if global warming increases water temperatures. The water supply can become contaminated when there are large-scale die-offs.

Effects of Water Pollution

Diseases such as giardia, cholera, hepatitis A, Legionnaires’ disease, schistosomiasis, and typhoid are often transmitted via polluted water. Many of these diseases are associated with significant gastrointestinal symptoms. Globally, 829,000 diarrhea-related fatalities are caused by polluted drinking water every year.

Approximately 7,2 million Americans fall ill every year due to pollutants in their drinking water. According to the Centers for Disease Control, between 8,000 and 18,000 individuals are hospitalized annually due to Legionnaires’ disease, a lung illness caused by polluted aerosols in piped water systems.

The detrimental health impacts of water contamination often disproportionately affect low-income communities. Sources of water pollution are more likely to be found close to their homes, and the water systems in these areas are often aging. The Flint water crisis in Flint, Michigan, in which 12 people died and thousands more were exposed to water contaminated with lead, is the most recent example.

How Is Drinking Water Quality Assessed in the US?

The Environmental Protection Agency keeps an eye on the condition of America’s drinking water supplies and collaborates with other government agencies, including the Food and Drug Administration (FDA), to disseminate information and educate the public on best practices for maintaining safe drinking water. 

Additionally, the Safe Drinking Water Act of 1974 safeguards water quality, especially for potable water. The purpose of this law is to ensure that all people in the United States have access to clean drinking water that meets established standards.

American Indian tribes and state environmental-control agencies play important roles in monitoring safe drinking water, and both employ rigorous monitoring strategies. When the EPA awards funding for pollution control and environmental management, the recipients are expected to use the money to set up and maintain monitoring systems and to report the outcomes of these programs to the EPA.

In addition to individual states and indigenous groups, interstate commissions can apply for funding and keep up their own monitoring initiatives. The environmental departments of many cities and counties also monitor water quality within their jurisdictions. The EPA aids in the administration of monitoring grants for water quality and offers technical advice on how to monitor and submit monitoring data.

The Lead and Copper Rule

In 1991, the EPA established a rule to limit the presence of lead and copper in drinking water. This rule is aptly, if uncreatively, called the Lead and Copper Rule (LCR).

The LCR requires the monitoring of drinking water, and if lead registers above a threshold of 15 ppb (parts per billion) or copper concentrations surpass an action level of 1.3 ppm (parts per million) in more than 10% of tested customer taps, the system must take further measures to prevent corrosion.

For more information about the Lead and Copper Rule, and to read about its most recent adaptations, this page from Harvard has a lot to say about it. 

How to Safeguard Your Home From Contaminated Drinking Water

The distribution of clean water to our houses via municipal water supplies is one of the distinctive attributes of modern life. Modern water distribution systems test and treat water to guarantee that it is safe for drinking, cooking, cleaning, and other uses. But it is not foolproof, as the residents of Flint will tell you.

A practical option to guarantee that the tap water you use is as clean as possible is to install a water filtration system in your home, such as a whole-house water softener or a point-of-use water filter on the water line at your kitchen sink or another water source.

If you want to learn more about the benefits of having a water softening system at home, this article provides more in-depth knowledge.

Here are some more steps you can take to prevent water contamination:

Keep pets on leashes while near bodies of water

Instead of taking your dog for a stroll by the shore of a lake or a river, look for a grassy or wooded area. That way, even if the pathogens in pet waste get into the ground, they won’t be able to pollute any drinking water supplies.

Reduce the use of strong pesticides and herbicides

Instead, adopt natural, harmless approaches, such as planting insect-resistant plants and utilizing beneficial—native!—insects, or limiting the accumulation of pest food sources.

Use soaps and detergents that don’t have phosphates

Using detergents and soaps without phosphates helps prevent an excess of nutrients from causing algae blooms in water systems. This wasn’t always easy, but it’s getting easier. Explore the Environmental Working Group’s Guide to Healthy Cleaning to find out how you can incorporate eco-friendly cleaning products into your home.

Appliances should be used sparingly

Using your dishwasher and washing machine efficiently is important. If you use these appliances only when they are full, you will use less detergent, resulting in fewer pollutants in your wastewater.

Embrace environmentally sustainable farming

If you have access to local organic farms, purchasing some of your food from them is an excellent way to reduce your environmental footprint. You’ll have access to fresh, locally produced goods, and you’ll know that no pesticides or herbicides were added to the local water supply. Supporting free-range farms in which animals are not confined to feedlots protects the water supply from animal waste concentration.

This has the added bonus that you’ll be over to lord it over your whole friend group that you only buy local produce.

Have your septic system examined by a professional

A professional inspection ensures that effluent is not escaping into the environment from your septic system.

Final Thoughts

If you’ve been exploring drinking water filters and water softeners but didn’t have the background to really understand why you need them, I hope this article answered some questions for you.

Americans are very fortunate when it comes to water quality, but the water supply here isn’t perfect.

However, if you install a water filtration system in your house, drinking contaminated water is no longer a concern. Filtered water is safer to use since the filtering system eliminates contaminants and chemicals. Water is essential for survival, so you must keep up to date on water quality in your area and ensure that you and your family consume filtered, clean water.