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Types of Water Contamination: Definition, Amount, Effect

different types of contaminants in drinking water Water contamination is the release of various substances into water bodies that make water unfit for human consumption and negatively affect aquatic ecosystems. Also, water contamination may include energy release in the form of heat or radioactivity. There are mainly four types of water contamination.

The most common types of water contamination are:

  • Physical contamination: Physical contamination affects the physical appearance and physical properties of water. Some examples of physical contamination would be the organic material from soil erosion suspended in the water bodies.
  • Chemical contamination: Chemical water contamination affects both underground and surface water bodies, mainly caused by the agricultural industry. Apart from the pesticides used in farming, metals and solvents from industrial sites also pollute water.
  • Microbiological contamination: Microbiological contamination occurs naturally. Harmful pathogens such as protozoa, bacteria, or viruses may cause diseases like cholera.
  • Radiological contamination: Chemical elements with unstable atoms emit ionizing radiation, thus making the water unfit for usage. Both humans and animal species are negatively affected by radiological contamination. To determine the concentration of the radioactive contaminants in drinking water, a continuous screening of alpha and beta radiation is recommended. The maximum contaminant level (MCL) represents the safe level of these contaminants in drinking water and has been established for various radionuclides. For uranium, the MCL is 4 millirems per year, while the MCL for radium has been set to 5 picocuries per liter. There is no MCL for radon at the moment.

The water contaminants that are currently not subject to any proposed or promulgated national primary drinking water regulations but are known to occur in public water systems are listed on the CCL (Contaminant Candidate List).

1. Physical Contamination in Water

Physical contamination affects the physical properties of water, such as color, odor, turbidity, and pH. Although physical contamination in water does not necessarily harm human health, using physically contaminated water might negatively affect domestic usage.

  • Color contamination: This type of pollution is caused by dye, metals, soil particles, or excessive growth of some algae. Although color contamination is not always harmful to human health, it can negatively affect appearance. Dye wastewater, though, poses toxic effects due to the toxic substances included in many dyes.
  • Odor and taste: Bad odor is caused by metals or microorganisms that produce musty odors. Depending on the concentration of the contaminant, the polluted water might affect human health. Nevertheless, bad-smelling and tasting water is not appealing to anybody.
  • Turbidity: High turbidity values usually appear after rainfalls and are caused by the soil carried by rain in water bodies. Turbid water has an unpleasant appearance and also damages treatment plants by clogging the treatment systems.
  • pH: A pH value higher or lower than neutral negatively affects the ecosystem. The high acidity of water prevents the growth of living organisms in water bodies and also affects the growth of plants and agricultural products. Corrosion is another negative effect of a low pH.

Even if physical contamination in water does not always affect human health as chemical contamination does, it still needs to be prevented. Also, the physical contaminants must be removed from drinking water. The best water treatment method used to remove physical contaminants is the reverse osmosis water filtration system. A RO system offers a strong filtration of most contaminants like dissolved salts, cysts, iron, and many more.

2. Chemical Contamination in Water

Chemical contamination in water can occur naturally or are caused by human activities, and the chemical contaminants are either organic or inorganic chemicals. Although physical contamination in water implies the presence of inorganic and organic compounds, it does not necessarily affect human health as chemical contamination does. Pharmaceuticals, pesticides, or heavy metals pose a high risk for human health, while different sediments only affect the water’s physical properties such as taste, odor, or appearance.

A broader list for chemical contaminants in water, though, includes the following chemicals:

  • Fluoride: Used for tooth decay prevention, fluoride harms human health when present in excess. Associated with dental and skeletal fluorosis and Alzheimer’s disease, fluoride concentration can be significantly reduced with a reverse osmosis water filtration system.
  • Byproducts of water treatment: Water treatment can use different chemicals such as chlorine and chloramine. Although these compounds do not harm human health, they give water an unpleasant taste and odor. To improve the water quality, the most common method uses activated carbon water filtration systems.
  • Agricultural chemicals: Pesticides and fungicides are some of the most common pollutants that negatively affect the ecosystem. Another important contaminant is nitrate, a substance that may cause methemoglobinemia (blue baby syndrome). The agricultural chemicals can be effectively removed or reduced using an ion exchange water filtration system.
  • Chemicals resulting from urban pollution: Industry and human lodgings produce the highest water contamination. Heavy metals, solvents, petroleum oils, and many more contaminants reach different water bodies and groundwater. These contaminants can be removed by using a selective ion exchange resin water filtration system.
  • Pharmaceuticals: These substances reach the water bodies via the sewage system. The effect they have on the ecosystem can be catastrophic, especially if high concentrations are involved. Human health is also affected by these substances. The best methods to remove pharmaceuticals from water are ozonization and activated carbon filtration.
  • Metals: Although some metals have beneficial effects on human health, others may induce serious diseases (heavy metals). Also, these compounds cause water turbidity and coloration. The best method to remove metals is the usage of an activated carbon water filtration system.

 3. Biological Contamination in Water

Biological contamination in water is caused by the presence of living organisms such as protozoa, bacteria, viruses, and algae. These microorganisms can negatively affect the ecosystem (excessive growth) and potentially harm human health. For example, the algae’s excessive growth negatively affects water’s physical properties and harms the aquatic ecosystem. Nevertheless, their effect on human health is not necessarily harmful. However, other biological contaminants such as some bacteria or viruses may cause severe diseases. From this point of view, biological contamination in water is far more dangerous than physical pollution.

  • Algae: Phosphorus contamination might cause the excessive growth of algae in water bodies. Due to this pollution, the water becomes unfit for domestic usage. Moreover, the water has an unpleasant odor, and it becomes unsuitable for many living aquatic organisms.
  • Bacteria: These microorganisms are known for causing severe diseases such as cholera, dysentery, typhoid, and gastroenteritis. The non-pathogenic bacteria, although they are not harmful to human health, give water a bad odor and taste.
  • Protozoa: Some protozoans like Giardia or Cryptosporidium pollute water bodies due to sewage waste waters and animal feces. These microorganisms may cause diarrhea, nausea, stomach cramps, and many other unwanted symptoms.
  • Viruses: The smallest microorganisms but also some of the deadliest contaminate water and produce infections and diseases like hepatitis and polio.

Due to the harmful effects of biological contamination in water, using an effective water purification system is essential. Although some filtration media are capable of reducing the concentration of harmful biological contaminants, the most effective water filtration system to remove the biological contaminants in water remains the Ultraviolet water purification system.

4. Radiological Contamination in Water

The chemical elements with unstable atoms due to the unbalanced number of protons and neutrons can emit ionizing radiation. Contaminants like uranium, cesium, or plutonium end up in water bodies due to industrial waste or the erosion of radioactive minerals. Any radiological contamination in water is proven to increase the risk of cancer.

Although radiological contamination is, in fact, chemical pollution of water, its effects are far more dangerous for human health. People exposed to high levels of radionuclides for extensive periods may develop severe health issues such as anemia, cancer, impaired immune system, bone growth, or osteoporosis.

The best methods to remove radiological contaminants are activated carbon filtration, filtration through materials enriched with Mangan oxides, or membrane separation.

What is Contaminant Candidate List (CCL)?

The Contaminant Candidate List (CCL) is a  list of drinking water contaminants known or anticipated to occur in public water systems and are not currently subject to EPA (the United States Environmental Protection Agency) drinking water regulations.

Safe Drinking Water Act (SDWA) requires the EPA to produce and publish the CCL every five years. Also, SDWA conducts EPA to consider the health effects and occurrence information for the unregulated pollutants. The contaminants present on the Candidate Contaminant List pose the most significant public risk for health. EPA uses the CCL to identify contaminants of the greatest importance for regulatory decision-making and information gathering.

On July 19, 2021, the EPA published CCL 5 as a draft and includes 66 chemicals (PFAS, cyanotoxins, and disinfection byproducts) and 12 microbes selected from various biological toxins, waterborne pathogens, and pesticides. Some of the contaminants included in draft CCL 5 are:

  • Chemicals: bisphenol A, multiple PFAS, pharmaceuticals, Lithium, Cobalt
  • Disinfection byproducts: nitrosamines, iodinated trihalomethanes, formaldehyde, chlorate
  • Microbes: enteroviruses, adenovirus, Helicobacter pylori

Since most contaminants included on the Contaminant Candidate List are pharmaceutical substances or disinfection byproducts, the best water purification method to remove the contaminants on the CCL from water is the ion exchange resin used in conjunction with an activated carbon filter.

What is the main contaminant for water pollution?

potential contaminants in waterThe most common water contaminant in the United States is represented by the so-called “forever chemicals”, PFAS (perfluoroalkyl and polyfluoroalkyl substances). Of the more than 9,000 existing PFAS, over 600 are widely used in the U.S. in numerous products. Unfortunately, although present on the CCL, no federal limits have been set on the concentration of these chemicals in the water.

Due to their strong carbon-fluorine bond, the PFAS build up into the environment and linger on geological timescales. Since these chemicals are widely used, they are present everywhere, including the human body. According to the U.S. Centers for Disease Control and Prevention, the PFAS are present in the blood of everyone who tested for them. Scientists conducted a series of tests across the country and linked many health concerns to PFAS: kidney cancer, liver damage, thyroid disease, or pregnancy-induced preeclampsia due to water pollution.

Effective methods to remove PFAS from both municipal and household levels exist. Granular activated carbon filters and reverse osmosis systems are water filtering systems proven effective against PFAS.

What is the situation in the United States for Water Contamination?

During the past decade, nearly a fifth of the United States population was exposed to contaminated water more than once. The research conducted by the Environmental Protection Agency revealed how six decades of farming pollution, industrial dumping, and distribution pipe deterioration negatively affected the local water systems.

Many large cities violated EPA standards, thus exposing millions of people to unsafe drinking water. Due to the old water systems’ infrastructure, several communities experienced water crises.

  1. Flint River, Michigan: The Flint water crisis lasted from 2014 until 2019 and was caused by the municipality failing to apply corrosion inhibitors to the water, thus leading to aging pipes to leak lead in the water supply. Between 6,000 and 12,000 children were exposed to lead poisoning, a contaminant known to cause reduction of intellectual functioning and increased chance of Alzheimer’s disease.
  2. Corpus Christi, Texas: In December 2016, an asphalt emulsifier, Indulin AA-86, corroded the water system pipes and polluted the tap water. The situation lasted for nearly 18 months, but this was not the first time citizens of this city experienced issues. Back in July 2015, the authorities issued an alert regarding E. Coli contamination of the tap water.
  3. Newark, New Jersey: Another water crisis caused by the aging water system in the U.S. was experienced by Newark, New Jersey. Back in March 2016, high levels of lead were reported. And, this lead exposure was significantly affecting the children. In 2020, the high levels of lead showed a drop after replacing lead drinking water pipes throughout the city.

Is contaminant water a reason for a legal lawsuit?

Yes, contaminated water is a reason for a legal lawsuit because federal and state regulations are meant to protect people from drinking or being in contact with polluted water. Also, people who suffered illness due to exposure to contaminated water might be entitled to compensation for medical costs.

The two laws that set standards for drinking water quality are:

  • Clean Water Act: Initially known as Federal Water Pollution Control Act, this document establishes the basic structure for regulating discharges of contaminants into U.S. waters and sets quality standards for the surface waters. Although states might have their pollution control criteria, these regulations must meet the federal standards.
  • Safe Drinking Water Act: This federal law regulates and protects drinking water drawn from public sources such as groundwater wells, springs, rivers, or lakes.

States also establish their drinking water standards, but these must meet the federal standards set by EPA (Environmental Protection Agency). Failing to comply with the Clean Water Act and the Safe Drinking Water Act can be important in the water litigation process.

What are the methods to solve the contamination problem of drinking water?

solving the contamination problem of drinking waterWater contamination is one of the main environmental issues worldwide. Human activity is primarily responsible for water contamination, although natural phenomena may degrade the water quality.

Some of the methods to solve the drinking water contamination are listed below:

  • Wastewater treatment: Removing contaminants from wastewater is essential for obtaining clean and safe drinking water. Water filtration systems such as reverse osmosis or activated carbon filtration proved effective in removing or reducing pollutants. Other solutions are bioremediation (microorganisms naturally found in the water digesting chemicals from gas or oil spills) and phytoremediation (the trees’ roots remove contaminants from deep aquifers). Chemical oxidation (oxidants convert harmful chemicals into less damaging substances like water or carbon dioxide) is also an effective solution.
  • Green agriculture: Throughout the world, agriculture is responsible for the poor quality of ground and surface water. The primary contaminants from agricultural runoff are nutrients (nitrogen and phosphorus), pesticides, and herbicides. For nutrient removal, the best solution is a specialized nutrient runoff reverse osmosis filtration system. One of the best products capable of removing up to 99% of nutrients is the HyperLogic Commercial reverse osmosis system.
  • Stormwater management: The runoff of rainwater and melted snow is also an important water contamination factor. An effective system of cleaning stormwater is the StormFilter filtration system. The filters used by this system contain different media such as per lite, zeolites, or CSF leaf (pure deciduous leaves turned into stable compost). These filters retain oils, greases, soluble heavy metals, nitrates, or phosphorus.
  • Air pollution prevention: Air pollution negatively impacts water quality as oceans also absorb carbon dioxide emissions, and this contamination causes water acidification which threatens the marine ecosystem.
  • Plastic waste reduction: More than 80% of plastic found in water bodies come from land sources. Plastic waste reduction can be achieved by choosing alternative biodegradable materials. Also, choose an efficient home water filtration filter and stop buying plastic bottles.
  • Water conservation: Although the Earth’s surface is 70% water-covered, drinking water is scarce. Preserving water can be achieved by properly managing this resource by each individual.

How to Clean Physical Contamination in Water?

Physical contamination refers to the presence of pollutants that affect the water’s physical properties, including its appearance. Physical contaminants (including particles from soil erosion and algae) are easy to remove through sedimentation, filtration, coagulation, or aeration. Activated carbon filters are an effective method of eliminating such contaminants.

How to filter Chemical Contamination in Water?

Chemical contamination of water includes chemical substances such as heavy metals, toxins, nutrients, pharmaceuticals, or nutrients. These man-made substances end up in water bodies due to agricultural runoff, poor wastewater management, or due to aging piping systems. The Clean Water Act regulates the types and amount of these pollutants. One of the best ways to remove a high percentage of the chemical contaminants in water is using a reverse osmosis system that incorporates activated carbon filters.

How to Purify Biological Contamination in Water?

Biological contamination in water refers to the presence of microorganisms in drinking water. Harmful pathogens such as bacteria, protozoans, or viruses negatively affect the water quality and pose a high risk for human health. These microorganisms are being removed from water through the purification process. The water purification process of biological contamination includes distillation, deionization, and Ultraviolet purification.

How to Refine Radiological Contamination in Water?

Radionuclides pose a high risk to human health, especially if present in drinking water. Removing such contaminants is not easy but can be achieved by using a combined purification system. Combining treatment methods such as carbon filtration, ion exchange resins, and reverse osmosis is the most effective way to bring radionuclides level to the EPA’s legal limits. The MCLs (maximum contaminant level) differ from one contaminant to another and depend on its risk to human health.

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