Table of Contents
What is water pollution?
Water pollution is the contamination of water bodies with substances that interfere with the natural functioning and beneficial use of the water bodies. This occurs mainly as a result of anthropogenic activities that cause the release of substances such as chemicals or pathogens into the subsurface groundwater, lakes, rivers, estuaries, rivers, and oceans affecting their ecology.
Apart from chemical substances and pathogens, the release of energy in form of radioactivity or heat into an aquatic ecosystem can also lead to water pollution.
Water pollution causes negative effects on the ecosystem at large as it reduces the ability of the water body to render the ecosystem services that it is meant to give. Once contaminants are introduced into the water, aquatic species can die and humans too can be affected with water-borne diseases.
These organisms, contaminants, or substances that pollute the water are called water pollutants. They make the water unusable for drinking, swimming, cooking, cleaning, recreation, and other activities. Typical examples of water pollutants are chemicals, municipal solid waste (trash), bacteria, fuel, oil, parasites, algal bloom, etc.
The fact is that all other forms of pollution find their way eventually to water. For instance, the polluted air settles onto lakes and oceans.
Moreso, air pollutants during precipitation can get dissolved in water drops and acidify them which later falls as rain. This polluted rainwater is called acid rain. Also, when the land is polluted too, the pollutants can seep into an underground stream and then to a river, and finally to the ocean. This means that dumping waste in a vacant lot or emitting toxic gases can indirectly pollute a water supply.
Pollution doesn’t just happen one day, it is the result of a cumulative effect over time. Supplying clean drinking water is an essential ecosystem service rendered by many freshwater systems. However, due to water pollution, approximately 785 000 000 people in the world have been deprived of access to clean drinking water.
There are basically four main sources attributed to water pollution which include sewage, agriculture, industry, and urban runoff including stormwater. These sources of water pollution could be either a point source or non-point source pollution.
The United States Environmental Protection Agency (EPA) explains a point source pollution as the contamination of an environment from an easily identifiable and confined space. Point source pollution is easily identifiable and comes from a single place whereas non-source pollution is more diffuse and harder to identify and address. Non-source pollution contaminants come from many places all at once to pollute the environment.
Power plants and factories can be sources of point-source pollutants that contaminate both water and air. Examples of point source pollution are drainage ditches, smokestacks, and discharge pipes. Gases like carbon monoxides, sulfur dioxide, nitrogen dioxide, or particulate matter as well as heavy metals can be spewed into the air by smokestacks.
Moreso, the water that is being used in paper mills. oil refineries and auto plants during their manufacturing processes can be discharged as wastewater (effluent) that contains harmful chemical pollutants into water bodies.
Another common source of point-source pollution is the municipal wastewater treatment plant. The effluent from this plant can introduce harmful microbes and nutrients into the waterways. These nutrients in water have an adverse effect as they can lead to the rampant growth of algae in the water body. Hence, reducing the quality of the water.
Runoffs are typical examples of non-point sources as the pollutants are released in a wide area. For instance, during a thunderstorm, rain flows over asphalt and wash away drops of oil that leaked from car engines, trash, dog waste, and particles of tire rubber. This runoff then goes into a storm sewer and eventually ends up in a nearby river. Hence, urban runoff and agricultural runoff is a major cause of non-point source pollution.
Types of water pollution
- Chemical pollution
- Groundwater pollution
- Microbiological pollution
- Nutrient pollution
- Oxygen-depletion pollution
- Surface water pollution
- Thermal pollution
This is the most common of all types of water pollution, whereby chemicals infiltrate the surface water of the earth and the underground water sources. The majority of the chemical contamination of these water bodies comes from the agricultural industries due to the use of pesticides and fungicides in farming. However, other leading contributors to chemical pollution are the metal and solvents from industrial sites.
Surface water pollution
This water pollution type involves the contamination of water sources that are above the ground such as seas, lakes, rivers, and oceans. Surface water pollution can be natural, intentional, or accidental.
A major contributor to this pollution is oil spills and negligent industries that empty their waste into water bodies. Human activities that involve mining, agriculture, factory effluent, human/animal waste disposal, landfills, poor waste management system, etc are all common sources of surface water pollution. Flood also can be a natural source of surface water pollution.
Suspended matter on surface water is an intentional form of surface water pollution by humans. Humans improperly discard waste such as fragments of rubber, plastics, and other man-made materials into the water. These things are too robust and probably not biodegradable and so persist for long in water bodies.
Some hardly mix with water molecules and they just simply float on the water surface. Hence, preventing sunlight and oxygen from penetrating below to the aquatic life underwater.
Agriculture is a major source of water pollution, especially groundwater pollution. During agricultural practices, farmers and gardeners apply fertilizers and pesticides to their crops.
These pesticides, fungicides, and fertilizers can seep into the ground and contaminate the groundwater (underwater rivers and waterbeds). This contamination eventually compromises the quality of water gotten from wells, boreholes, and other water sources that groundwater is gotten from for human use.
This is one of the types of water pollution that is different compared to others. Microbiological pollution is a form of water contamination that occurs naturally. It involves microorganisms such as bacteria, viruses, protists (protozoa), and nematodes infiltrating water supplies.
These microbes can cause diseases like bilharzia and cholera to humans and other life forms. Therefore, humans in places with inadequate water treatment systems established are the most susceptible to this type of pollution in water.
This type of water pollution is vital for the bloom of underwater flora and fauna but in turn, affects the water quality of the water body. Nutrient pollution is a result of excess nutrients in the water body which can lead to eutrophication. During eutrophic conditions, there is an increase in sedimentary material and nutrients like nitrogen and phosphorous.
The excess nutrients in the rivers, lakes, and coastal areas can upset the delicate imbalance of water-based ecosystems.
Fertilizers are thereby associated with nutrient pollution as they contain a high concentration of nutrients like phosphorous and nitrogen. When these excess nutrients find their way into a water body and contaminate it, an algal bloom occurs which can block sunlight and inhibit the growth of other organisms in the water.
Due to the enrichment of the water by nitrogen and phosphorous nutrients, the growth of organisms like aquatic plants, plankton, and algal are stimulated.
This form of pollution is the reason for the water being murky as well as the formation of extensive mats of floating plants on the surface of water bodies. Typical examples of such plants are the water hyacinths, Nile cabbage, and algal bloom.
As these plants develop and bloom on the surfaces of the water, they prevent the penetration of light and absorption of oxygen that is needed by organisms underwater. Hence, such water supports fewer aquatic organisms.
This water pollution type is caused by algal bloom. It involves the depletion of oxygen in the water as a result of algal bloom. Therefore, species in the water that depend on oxygen for survival end up dying whereas, the anaerobic species survive.
The majority of these anaerobic species are microorganisms. These anaerobic microorganisms thriving in the water release and produce ammonia, sulfide, and other harmful toxins that make the water unconducive and unhealthy to animals and even humans.
Heat can be one of the causes of water pollution and when this occurs it is termed thermal pollution or thermal enrichment. This type of water pollution is the degradation of water quality by processes that can change the ambient temperature of the water.
Thermal pollution is caused by human influence and unlike chemical pollution, it leads to changes in the physical properties of water. Power plants and industrial manufacturers using water as a coolant is the common cause of thermal pollution.
Heat decreases the capacity of the water body to hold dissolved oxygen in solution and the rate of metabolism in fish increases. The very low levels of dissolved oxygen in water make it unconducive for valuable species of game fish (e.g trout) to survive.
The discharge of cooling water from power plants into water bodies is the main source of heat causing pollution in water. This discharged water can be about 15 °C (27 °F) warmer than the temperature of the natural water. An example of this type of water pollution is seen in Massachusetts where heated water is discharged into Mount hope bay by the Brayton point power station.
Causes of water pollution
- Agricultural practices involving the use of fertilizers and chemicals like fungicides, pesticides, and herbicides for the control of weeds and pests
- Poor sanitation and inadequate sewage treatment system
- Indiscriminate waste disposal and poor waste management system
- Discharge of untreated industrial effluents
- Oil and fuel spills
- Food products spills
- Leaks from cars and machines or chemical containers
- Soil erosion
- Urban run-offs that contain chemicals or salts (during winter months)
Water pollution can be caused by a lot of different contaminants, toxic waste, and pathogens from various sources. The fact is all human activities that generate sewage, and toxic waste cause pollution in water once the water is contaminated with poisonous substances and disease-causing microbes. Water pollution definitely takes a toll on the surrounding environment, humans, animals, and plants.
The use of fertilizers and chemicals like fungicides, pesticides, and herbicides for the control of weeds and pests during farming operations can cause pollution in water.
Runoffs from agricultural areas usually contain high levels of pesticides, nitrogen, or phosphorous-containing compounds. Once, the excess nutrients contained in this runoff from farms get to a water body, it pollutes the water and causes eutrophication.
Moreso, there are water pollutants associated with fish farming that is released by fish farms. They include organic products (fish feces and uneaten feed pellets), pharmaceuticals, and chemicals. These enormous amounts of pollutants enter the aquatic ecosystem and usually cause water pollution.
Poor sanitation and inadequate sewage treatment system
One of the causes of water pollution is poor sanitation and inadequate sewage treatment system in cities. Domestic sewage contains pathogens or a lot of compounds from feces, organic waste, cosmetics, personal hygiene products, pharmaceuticals, etc.
Once the sewage from various homes is not properly treated, the pollutants they contain can cause water pollution.
This domestic sewage can also be a main source of nutrients in the water where the excess phosphates and nitrates they contain pollute the water and stimulate the growth of algae. Sewage has a number of pathogens and needs to be treated.
A high number of pathogens in a water body come from human feces (open defecation), blackwater, sewage, and manure that find their way into the water body. This high level of pathogens in water can be a result of a lack of sanitation or poorly functioning on-site sanitation systems and inadequate sewage treatment systems.
Indiscriminate waste disposal and poor waste management system
Disposal of waste indiscriminately can cause water pollution because once the land is polluted, the pollutants can seep into an underground stream and then to a river and finally to the ocean. Suspended matter on surface water is an intentional surface water pollution.
Due to poor waste management systems, humans improperly discard waste such as fragments of rubber, plastics, and other man-made materials into the water. These things are too robust and probably not biodegradable and so persist for long in water bodies. Some hardly mix with water molecules and they just simply float on the water surface.
A flood can cause water pollution too. During rain events, simple pit latrines may get flooded. Hence, water can get polluted during storm events, when sewers overflow, thereby polluting the water from untreated sewage. These kinds of events are referred to as sanitary sewer overflows or combined sewer overflows.
During a thunderstorm, rain flows over asphalt and wash away drops of oil that leaked from car engines, trash, dog waste, and particles of tire rubber. This runoff then goes into a storm sewer and eventually ends up in a nearby river.
Discharge of untreated industrial effluents
The discharge of untreated industrial wastewater into the water is one of the main causes of water pollution. Industries like power plants, iron, and steel mills, petroleum refineries, pulp, and paper mills, and food processing industries may discharge their solvents, chemical waste, heavy metals, and other harmful pollutants such as nutrients into water bodies without proper treatment.
Certain industries like the food processing industries discharge high concentrations of oil, biochemical oxygen demand (BOD), and grease. These effluents cause pollution in the water.
Oil and fuel spills
This involves the release of liquid petroleum hydrocarbon into the water body as a result of human activity. Marine oil spills cause pollution in water and land.
This happens due to the release of crude oil from tankers, drilling rigs, offshore platforms, and wells. Refined petroleum products (diesel and gasoline) and their by-products may spill also as well as heavier fuels or oily refuse or waste oil.
Soil erosion and Urban run-offs
Due to soil erosion, sediments are carried into the water body by surface runoffs. The presence of these suspended sediments in the water causes pollution and interferes with the penetration of sunlight into the water.
Urban runoffs are the stormwater that is discharged from rooftops, parking lots, roads, and reservoirs to surface waters. Usually, urban runoffs are prone to high suspended solids, as well as high phosphorous and nitrogen concentrations, thereby causing pollution in water.
What pollutes water?
These substances that pollute the water are called water pollutants and could be a single substance, a combination of different substances, or microbial diversity. A water pollutant can come from a point source or nonpoint source. For instance, the pipe or channel used for discharge from a city sewage system or an industrial facility is a typical example of a point source.
The water pollutants from these point sources are easy to control compared to the dispersed source. This is because the contaminated water can be collected and conveyed to one single point for treatment.
The dispersed source (nonpoint source) is very broad and is an unconfined area where various pollutants enter the water body.
A typical example of a non-source pollutant is the runoff from agricultural areas. In fact, non-source pollutants still cause a large fraction of water pollution problems because it is difficult to control. Even though there has been much progress in building modern sewage treatment sources, these pollutants have still been difficult to treat or control.
- Pathogens from sewage
- Toxic waste
- Industrial wastewater
- Heat in thermal pollution
- Runoffs from farms
- Urban runoffs
Let us look at each of these types of water pollutants and how they pollute the water.
Domestic sewage is one of the primary causes of water pollution because it is a source of disease-causing microorganisms (pathogens) and putrescible organic substances.
Some pathogens are excreted in feces and as a result, all sewage from towns and cities are likely to contain certain types of pathogen. This proposes a potential direct threat to public health.
Sewage is literally made up of 99.9% water and 0.1% solids. As of 2017, according to an estimate by the joint monitoring program for water supply and sanitation, about 4.5 billion people don’t have safely managed sanitation. This lack of access to sanitation thereby leads to pollution in water.
Also, during rain events, simple pit latrines may get flooded. Water can get polluted during storm events, when sewers overflow, thus polluting the water from untreated sewage. These kinds of events are referred to as sanitary sewer overflows or combined sewer overflows.
Putrescible organic waste gives a different kind of threat to the quality of water. The dissolved oxygen content in water is depleted as bacteria and other microbes naturally decompose the organic waste in the sewage.
When oxygen is depleted, the quality of streams and lakes is endangered because there are fishes and other aquatic organisms in the water that require high levels of oxygen to survive. To reduce the number of pathogens present in the sewage, the wastewater is treated. Sewage treatment processes may reduce the levels of pathogens and organic in wastewater but may not eliminate them completely.
Sewage as a source of nutrient in the water
This domestic sewage can also be a main source of nutrients in the water such as phosphates and nitrates. As mentioned earlier, excess phosphates and nitrates pollute the water and stimulate the growth of algae. The growth of algae known as algal bloom becomes dense and rapid.
As these algae die, the dissolved oxygen in water reduces because microbes during the process of decomposition use the oxygen to break down and digest the algae. As these anaerobic organisms that do not need oxygen to survive, metabolize the organic waste, they release gases like hydrogen sulfide and methane in the water which is harmful to aerobic (oxygen-requiring) aquatic organisms.
Sewage is a contributor to many classes of nutrients e.g phosphate that leads to eutrophication. Eutrophication is the process at which a water body changes from a clean and healthy condition with a balanced aquatic community and low concentration of dissolved nutrients to a nutrient-rich, algae-filled state and eventually to an oxygen-deficient state.
This eutrophic process can occur naturally, or culturally. It is called cultural eutrophication when the whole process is accelerated by human activities and water pollution. Eutrophic levels can lead to premature aging and dead zone areas of the water body.
Sewage as a source of pharmaceutical and personal care products (PPCPs) in water
Domestic sewage usually contains diverse compounds that are found in cosmetics, pharmaceutical drugs, personal hygiene products, and their metabolites. The sewage can contain substances such as phthalates that in their actions mimic hormones.
Hormones from animal husbandry and residue from human hormonal contraception methods can be contained too in sewage. These water pollutants can have adverse impacts even at very low concentrations in water. Pollution in water as a result of environmental persistent pharmaceutical pollutants can have adverse consequences.
Since the 1990s, the environmental effect of pharmaceuticals and personal care products (PPCPs) has been investigated. The PPCPs comprise substances that individuals use for cosmetic or personal health reasons as well as the products used by agribusiness in order to boost the health or growth of their livestock.
Every year, more than twenty million tons of PPCPs are produced and around the world, PPCPs have been detected in water bodies.
More research is required to ascertain and evaluate the risks of toxicity, bioaccumulation, and persistence of these PPCPs. Current research, however, shows that pharmaceutical and personal care products have an impact on the environment and other species like coral reefs.
One type of persistent organic pollutants known as the environmental persistent pharmaceutical pollutants (EPPPs) is contained in the PPCPs. These pollutants are not removed in conventional sewage treatment plants. As persistent organic pollutants, they require a fourth treatment stage which many treatment plants do not have, unfortunately.
Pathogens from sewage
A high number of pathogens in a water body come from human feces (open defecation), blackwater, sewage, and manure that find their way into the water body. This high level of pathogens in water can be a result of the following:
- Lack of sanitation or poorly functioning on-site sanitation systems (pit latrines, septic tanks)
- Sewage treatment plants without disinfection steps
- Sanitary sewer overflows
- Confined sewer overflows during storm events and intensive agriculture (poorly managed livestock operations)
These pathogens can cause waterborne diseases in humans or animal hosts. There were findings from a study that was carried out in 2017 stating that polluted water spread parasitic infections and gastrointestinal diseases and that 1.8 million people were killed. Some of these common microbes in polluted water that is known to cause problems to human health include the following:
- Burkholderia pseudomallei
- Cryptosporidium parvum
- Giardia lamblia causes giardiasis
- Salmonella which causes Salmonellosis
- Norovirus and other viruses
- Parasitic worms including the Schistosoma type
This is one of the water pollutants. Toxic waste as water pollutants are wastes that are radioactive, poisonous, carcinogenic (cancer-causing), explosive, mutagenic (causing damage to chromosomes), bioaccumulative (increase in the concentration at the higher ends of food chains), or teratogenic (birth defects causing).
The sources of toxic waste and chemicals in water bodies include:
- Improperly disposed wastewater from industrial plants
- Wastewater from chemical process facilities (lead, mercury, chromium) that is disposed of improperly
- Surface runoff containing pesticides with compounds like chlordane, dieldrin, and heptachlor from agricultural areas and suburban lawns
Industrial wastewater is one of the well-known water pollutants. In the US for instance, industries like power plants, iron and steel mills, petroleum refineries, pulp and paper mills, and food processing industries are the main industrial consumers of water. They use over 60% of the total water consumed by industries.
Some of these industries discharge their solvents, chemical waste, heavy metals, and other harmful pollutants such as nutrients. Certain industries like the food processing industries discharge high concentrations of oil, biochemical oxygen demand (BOD), and grease. The discharge of some industries includes persistent organic pollutants such as synthetic organofluorine chemical compounds (per- and polyfluoroalkyl substances PFAS).
Another water pollutant is sediment e.g silt. Due to soil erosion, sediments are carried into a water body by surface runoffs. The presence of these suspended sediments in the water has an adverse effect.
The major effect of this water pollutant is that it interferes with the penetration of sunlight into the water. This in turn upsets the ecological balance of the water body. It can also disturb the reproductive cycles of fish and other aquatic life forms. Moreso, bottom-dwelling organisms can suffocate when these sediments settle out of suspension.
Heat in thermal pollution
Thermal pollution occurs in water bodies and heat is the major pollutant. Heat can be one of the causes of water pollution and when this occurs it is termed thermal pollution or thermal enrichment.
This is the degradation of water quality by processes that can change the ambient temperature of the water. Heat is said to be one of the causes of water pollution when it decreases the capacity of the water body to hold dissolved oxygen in solution.
Also, the rate of metabolism in fish increases as a result of heat. The very low levels of dissolved oxygen in water make it unconducive for valuable species of game fish (e.g trout) to survive.
The discharge of cooling water from power plants into water bodies is the main source of heat in thermal pollution. This discharged water can be about 15 °C (27 °F) warmer than the temperature of the natural water.
Power plants and industrial manufacturers using water as a coolant is the common cause of thermal pollution e.g heated water is discharged into Mount Hope Bay by the Brayton point power station in Massachusetts. Thermal pollution is mainly caused by human influence and unlike chemical pollution, it leads to the change in the physical properties of water.
Water pollution occurs when petroleum from parking lots or roads is carried into water bodies by surface runoffs.
Oil spilling accidentally is a source of oil pollution in water. A typical example of such pollution occurred in 1989 where 260,000 barrels were released in Alaska’s Prince William sound from the tanker Exxon Valdez. Also, in 2010 another oil spill happened in the Gulf of Mexico where more than 4 million barrels of oil were released from the Deepwater Horizon oil rig.
Oil slicks definitely find their way towards the shore. This eventually harms aquatic life and damage recreation areas.
Runoffs from farms
Agriculture contributes immensely to pollution in water. This is because of the use of fertilizers that lead to nutrient pollution. This nutrient pollution occurs in water due to the surface runoff from the following:
- Farm fields
- Discharges from septic tanks
Agricultural runoff usually contains high levels of pesticides. The excess nutrients contained in this runoff from farms usually have nitrogen or phosphorous-containing compounds. These compounds in excess in the water body pollute the water and cause eutrophication.
Also, fish farming is a source of pollution. There are pollutants that are released by fish farms which include organic products (fish feces and uneaten feed pellets), pharmaceuticals, and chemicals.
These enormous amounts of pollutants enter the aquatic ecosystem and usually cause inhabitable conditions for other aquatic species. The fact is there is no barrier between the farmed fish and their surrounding environment in open net-cage aquaculture. Moreso, fish farms can create a perfect environment for the transmission of disease.
These diseases can be transmitted easily to wild fish in open net-cages which can cause havoc on local populations.
This water pollutant is the stormwater that is discharged from rooftops, parking lots, roads, and reservoirs to surface waters. Usually, urban runoffs are captured in large retaining ponds. This is prone to high suspended solids, as well as high phosphorous and nitrogen concentrations.
The effects of water pollution
- One of the effects of water pollutants like sewage is that it can stimulate algae growth which eventually leads to eutrophic dead zones where the water lacks the oxygen to sustain aquatic life.
- Microplastics that contaminate the water can be found in marine wildlife. As seafood is consumed by humans, microplastics become concentrated in humans because of biomagnification. Therefore, water pollution can cause the biomagnification and bioaccumulation of toxic substances at different trophic levels.
- The effects of water pollutants such as petroleum when spilled can get mixed with runoffs and once in the water can strand and kill many different marine species.
- One effect of water pollution is that the hazardous chemicals, pesticides, and herbicides from various sources that pollute the water can cause acute toxicity and immediate death or chronic toxicity that lead to cancer or neurological problems in humans.
- Water pollution effects can be seen also when the human skin comes in contact with chemically polluted water from swimming in it or washing clothes with the water. This contact with such water can lead to skin irritation.
- The effects of water pollutants in a water body are that it can cause disease and can be toxic to any form of life that consumes the contaminated water or inhabits it. Parasites and bacteria in poorly treated sewage that find their way to the groundwater or surface water can enter drinking water supplies and cause digestive problems like diarrhea and cholera.
- One of the water pollution effects on humans is the inaccessibility to safe drinking water. Once the water is polluted, as humans use water for food preparation and drinking, water pollutants enter the body especially the digestive tract. From the digestive tract, these pollutants can get to other organs in the body and cause several illnesses.
- There are some diseases associated with pollution in water. Diseases caused by water pollution include amoebiasis, typhoid, giardiasis, hookworm infection, ascariasis, diarrhea, stomach cramps or aches, gastroenteritis, encephalitis, hepatitis, respiratory infections, cancer, liver damage, kidney damage, thyroid system disorder, reproductive and endocrine damage. Increased water pollution can cause breeding grounds for malaria-carrying mosquitoes.
- Water pollution causes the aesthetics of a water body to reduce drastically. When a water source is polluted, this can reduce or hinder recreational activities such as waterskiing, windsurfing, swimming, bathing, surfing, diving, tubing, and water play by children, in the water.
- Water pollution effects on plants and animals are on the rise as these organisms die or don’t reproduce properly because the water system on which they live or depend is polluted with hazardous substances.
- The effect of water pollution is associated with bioaccumulation and biomagnification of toxic substances in plants and animals. This causes the accumulation of harmful substances across the food chain which in turn causes illness, mutation, defects in births, and increased mortality rate.
Water pollution solutions
- One of the water pollution solutions involves the implementation of mandatory regulations.
- Water pollution can be controlled using important tools like environmental education, market forces, economic instruments, and stricter enforcement.
- Standards should be enforced and precise for a defined quantifiable maximum or minimum value for a pollutant.
- Market-based economic instruments can be implemented to control pollution such as subsidies, charges, deposit or refund schemes, enforcement incentives, and the creation of a market in pollution credits.
- Schemes and projects for recycling and reuse of waste products should be encouraged.
- In order to achieve water pollution solutions, appropriate infrastructure and management plans are needed. Such infrastructure may include sewage treatment plants and industrial wastewater treatment plants.
- Erosion control at construction sites can help control water pollution.
- Agricultural wastewater of farms should be treated.
- There should be effective control of urban runoff, where the speed and quantity of its flow should be reduced.
- One of the effective water pollution solutions is that at all levels there should be an ongoing evaluation and revision of water resource policy from the international level down to individual wells and aquifers.
- Domestic sewage should be treated by decentralized wastewater systems, centralized sewage treatment plants, onsite sewage facilities, and septic tanks or nature-based solutions.
- Safe and proper sanitation management services should be implemented to prevent water pollution.
- A well-designed and operational sewage system that has more advanced tertiary treatment or secondary treatment stages can help remove 90% or more of the pollutants present in sewage.
- During storm events, sewer overflows can be curtailed by timely maintenance and upgrades of the sewerage system.
- Industrial wastewater should be treated properly before being discharged to the water body. It should be ensured that the pollutant concentrations in the treated wastewater comply with the regulations regarding the disposal of wastewaters into sewers or water bodies.
- For confined animal operations such as egg and milk production, agricultural wastewater treatment is required to control pollution. Using mechanized treatment units, this can be done in plants.
- Constructed wetlands can be used to facilitate the treatment of animal wastes.
- Many farms are contributors to non-source point pollution. This can be controlled by farmers installing erosion controls that reduce runoff flows and retain the soil on their fields. Common erosion control techniques include crop mulching, contour plowing, crop rotation, contour plowing, installing riparian buffers, and planting perennial crops.
- Farmers can develop and use nutrient management plans that will reduce the excess application of nutrients. This will help to curtail nutrient pollution. They can make use of integrated pest management (IPM). These techniques will help maintain control over pests, protect water quality and reduce reliance on chemical pesticides. This will definitely help to minimize pesticide impacts on the environment.
- Erosion controls (hydroseeding and mulching) and sediments controls such as sediment basins and silt fences should be installed in construction sites to manage sediments from getting to water bodies.
- By using spill prevention and control plans as well as specially designed containers and structures (overflow controls and diversion berms), the discharge of toxic substances like motor fuels and concrete washouts can be prevented in order to control pollution.
- In order to reduce the effects of urban runoff, local governments should use several stormwater management techniques. In some countries, these techniques called best management practices for water pollution (BMPs) may focus on improving water quality while others focus on water quantity controls and some carry out both functions.
- Deforestation should be controlled because it leads to erosion and changes in hydrology. This eventually results in water pollution and the loss of sediments.
- In different countries, there are several pollution prevention practices which include low impact development (LID) or green infrastructure techniques. In the UK, it is known as sustainable drainage systems and in Australia and the middle east, we have the water-sensitive urban design (WSUD) such as installation of green roofs and improved chemical handling.
- There is some legislation that has been put in place to control water pollution. They are:
- The philippine clean water act of 2004, also known as Republic Act 9275 is a governing law in the Philippines on wastewater management. This law states that it is the country’s policy to preserve, protect, and revive the quality of its water bodies for which wastewater management plays a particular role.
- In the United States, the clean water act is the main federal law governing water pollution in surface water. In collaboration with territories, states, and tribes, this law was implemented by the US Environmental Protection Agency. Also, the groundwater protection provisions are included in the Resource Conservation and Recovery Act, the Superfund Act, and the Safe Drinking Water Act.
What can you do to control water pollution?
Make use of less water
- Making use of less water is sustainable because even though it may seem like clean freshwater is plentiful on earth, there is a limited amount available.
- Hence, try to make use of water-saving devices in toilets, showers, and on sinks.
- If possible, take short showers rather than baths.
- Quit the habit of running the water while brushing your teeth.
- If possible, water your plants and lawn when absolutely necessary.
- Try washing your clothes when you have a full load of laundry.
- Enjoy the use of water for drinking, swimming, eating, cleaning, etc. However, be cautious enough to not waste or pollute this limited precious resource.
Try to avoid pouring chemicals down the drain
- For house use, try to make use of fewer chemicals and cleaners around the house.
- Try to cut down on indoor air pollution.
- Most importantly, try to cut down on the number of chemicals entering the water system.
- If possible use only biodegradable cleaners.
- Avoid pouring chemicals or oil into the drainage system on the street.
Ensure you check your water for lead contamination
- There are many homes with lead pipes or lead-around connections on the pipes that carry water to their homes.
- This lead can find its way into your drinking water and so it’s advisable to test your water for lead cause it can cause serious medical problems in young children.
- However, if after testing and lead is found in your water, installing a filter may solve the problem.
Avoid contaminating and polluting outdoor water sources
- In as much as there is a drainage system on the street, do not pour chemicals or oil into the drainage system. Many plants and animals can be killed by these oil and substances.
- Avoid littering especially near water bodies as this litter can be eaten as food by animals which may cause harm to them.
- Make use of less fertilizer as these can enter water sources eventually.
- Avoid and reduce the use of pesticides on lawns. If possible use only organic pesticides on your lawns.
What is polluted water?
Polluted water is a water source or body that is contaminated by substances that make the water unhealthy or inhabitable. This sort of water, as a result of the pollutants in it, is unsafe for cooking, cleaning, drinking, swimming, and other activities. Substances such as chemicals, trash, bacteria, and parasites are examples of pollutants that make water polluted.
What causes water pollution?
Many anthropogenic activities that lead to the release of substances such as chemicals or pathogens into water bodies are the main causes of water pollution. Apart from chemical substances and pathogens, the release of energy in form of radioactivity or heat into an aquatic ecosystem can also cause water pollution. However, pollution doesn’t just happen one day, it is the result of the cumulative effect over time.
The fact is all other forms of pollution such as air pollution and land pollution find their way eventually to water. For instance, the polluted air settles onto lakes and oceans. Also, when the land is polluted too, the pollutants can seep into an underground stream and then to a river, and finally to the ocean. This means that dumping waste in a vacant lot or emitting toxic gases can indirectly pollute a water supply.
What are examples of water pollution?
- Gases like carbon monoxides, sulfur dioxide, nitrogen dioxide, or particulate matter as well as heavy metals can be spewed into the air by smokestacks which eventually settle onto water bodies.
- The water that is being used in paper mills, oil refineries, and auto plants during their manufacturing processes contains harmful chemical pollutants that are discharged as wastewater (effluent) into water bodies. This effluent being discharged into water is an example of water pollution.
- Surface runoff containing pesticides used on agricultural areas and suburban lawns finds its way to lakes, rivers, oceans, etc, and pollutes them.
- The improper disposal of wastewater from industrial plants into water bodies.
- The discharge of cooling water from power plants into water bodies causes pollution in water.
What is a water pollutant?
Water pollutants are substances or organisms that contaminate the water. These pollutants could be of microbial diversity, a single substance, or a combination of different substances. A water pollutant can come from a point source or nonpoint source. Examples of water pollutants include sewage, pathogens, toxic waste, industrial wastewater, sediment, heat, petroleum, runoffs from farms, and urban runoffs.