Ways To Reduce Water Pollution: What Not To Do

Water pollution is a pressing issue that jeopardises human health and safety. Unsafe water kills more people each year than war and all other forms of violence combined. Water pollution occurs when harmful substances, often chemicals or microorganisms, contaminate a body of water, rendering it toxic to both humans and the environment.

Water is particularly vulnerable to pollution due to its ability to dissolve more substances than any other liquid on Earth. This means that toxic substances from farms, towns, and factories readily dissolve and mix with water. The agricultural sector is a serious water polluter, with farming and livestock production using about 70% of the Earth's surface water supplies. Sewage and wastewater, as well as stormwater runoff, also contribute to water pollution. Oil pollution, including that from gasoline, is another major issue. Radioactive substances, which can persist in the environment for thousands of years, are another source of water pollution.

To address water pollution, it is important to understand the sources and types of pollution, and to take preventative measures. Point source pollution comes from a single source, such as a manufacturer or oil refinery, while nonpoint source pollution comes from diffuse sources such as agricultural or stormwater runoff. Groundwater, surface water, and ocean water can all be impacted by pollution, with ocean water pollution often originating on land.

Water pollution has severe effects, including the death of both humans and wildlife, as well as illnesses caused by waterborne pathogens. It can also lead to eutrophication, creating dead zones in water sources. Chemicals and heavy metals from industrial and municipal wastewater contaminate waterways, threatening aquatic life and accumulating in the food chain. Marine debris, particularly plastic, also poses a significant threat to marine life and ecosystems.

To prevent water pollution, individuals can reduce their plastic consumption, properly dispose of chemicals and non-biodegradable items, maintain their cars to prevent leaks, and avoid using pesticides and herbicides. Supporting policies such as the Clean Water Act and advocating for investments in infrastructure are also important steps in addressing water pollution.

Groundwater pollution

Sources of Groundwater Pollution

There are numerous sources of groundwater pollution, including:

• On-site sanitation systems
• Landfill leachate
• Effluent from wastewater treatment plants
• Leaking sewers
• Petrol filling stations
• Hydraulic fracturing (fracking)
• Over-application of fertilizers in agriculture
• Naturally occurring contaminants, such as arsenic or fluoride
• Storage tanks containing gasoline, oil, chemicals, or other liquids
• Septic systems
• Uncontrolled hazardous waste sites
• Landfills
• Chemicals and road salts
• Atmospheric contaminants

Health Hazards

Using polluted groundwater poses significant hazards to public health, including:

• Poisoning caused by toxins in well water supplies
• Diseases such as hepatitis and dysentery, caused by contamination from septic tank waste
• Water-borne diseases, such as typhoid, cholera, and diarrhea, caused by pathogens in feces and urine
• Certain types of cancer and other long-term health effects

Prevention and Management

To prevent groundwater pollution, several methods can be employed, including:

• Applying the precautionary principle
• Implementing groundwater quality monitoring programs
• Land zoning for groundwater protection
• Correctly locating on-site sanitation systems
• Applying relevant legislation

When groundwater pollution has already occurred, management approaches may include:

• Point-of-use water treatment
• Groundwater remediation
• Abandonment of the contaminated groundwater source and finding an alternative water source

Global Impact

Sewage and wastewater

Wastewater is a major threat to nature and human health. It is a toxic cocktail of pathogens, pharmaceuticals, microplastics, heavy metals, endocrine disruptors, and more. According to the United Nations, more than 80% of the world's wastewater is released back into the environment without being treated or reused. This has far-reaching consequences for climate resilience, aquatic biodiversity, and food and water security and access.

Wastewater treatment, also called sewage treatment, is the removal of impurities from wastewater before they reach aquifers or natural bodies of water. While pure water is not found in nature, any distinction between clean water and polluted water depends on the type and concentration of impurities found in the water, as well as its intended use. Water is said to be polluted when it contains enough impurities to make it unfit for a particular use, such as drinking, swimming, or fishing.

There are three types of wastewater: domestic, industrial, and storm. Domestic sewage carries used water from houses and apartments and is also called sanitary sewage. Industrial sewage is used water from manufacturing or chemical processes. Storm sewage, or stormwater, is runoff from precipitation that is collected in a system of pipes or open channels.

Wastewater treatment plants remove chemical or biological waste from water. The predominant method of wastewater disposal in large cities and towns is discharge into a body of surface water, while suburban and rural areas rely more on subsurface disposal. In either case, wastewater must be purified or treated to some degree to protect public health and water quality. Suspended particulates, biodegradable organics, pathogenic bacteria, and industrial wastes and toxic chemicals must be removed to varying extents.

There are three levels of wastewater treatment: primary, secondary, and tertiary (or advanced). Primary treatment removes about 60% of total suspended solids and about 35% of biochemical oxygen demand (BOD)—the amount of oxygen required by microorganisms to decompose organic substances in sewage. Secondary treatment removes more than 85% of both suspended solids and BOD. Tertiary treatment can remove more than 99% of all impurities from sewage, producing an effluent of almost drinking-water quality. However, it is very expensive, often doubling the cost of secondary treatment, and is only used under special circumstances.

The final destination of treated sewage sludge is usually the land. Dewatered sludge can be buried underground in a sanitary landfill or spread on agricultural land as a soil conditioner and fertilizer. Where a suitable site for land disposal is unavailable, as in urban areas, sludge may be incinerated.

Oil pollution

The Oil Pollution Act, passed in 1990 in the U.S., aims to prevent oil spill pollution and prepare emergency responses. This Act requires oil storage facilities to have a "Facility Response Plan" and mandates that companies have a cleanup plan to prevent spills.

Oil spills on land can be equally detrimental, with the potential to penetrate underground and reach groundwater. Pipeline ruptures, well blowouts, and human errors are common causes of land-based oil spills.

The persistence of oil pollution in the environment, including in sediments, can have long-term effects on ecosystems. Even when oil is no longer visible on the surface, it can remain biologically active in the underlying layers, affecting the behavior and survival of fauna.

The recent increase in oil drilling and transportation heightens the risk of oil spills and underscores the need for effective prevention, preparedness, and response strategies to mitigate their environmental and economic impacts.

Radioactive substances

Radioactive contamination can be caused by the release of radioactive gases, liquids, or particles. For example, a spill of a radionuclide used in nuclear medicine can spread through the environment as people walk around. Nuclear accidents, such as the Fukushima Daiichi and Chernobyl disasters, have resulted in widespread radioactive contamination.

The hazards posed by radioactive substances in water depend on the type and amount of the contaminant, as well as the duration and type of exposure. External irradiation from radioactive substances can pose risks to human health, especially from penetrating radiation like gamma rays and beta particles. Internal irradiation occurs when radioactive substances are ingested, inhaled, or absorbed, leading to irradiation of the body's tissues and organs.

The International Commission on Radiological Protection (ICRP) has developed guidelines to protect people living in areas with long-term radioactive contamination. These guidelines include monitoring and controlling the spread of contamination, decontaminating affected areas, and providing information and support to affected communities.

Nonpoint source pollution

• Excess fertilizers, herbicides, and insecticides from agricultural lands and residential areas.
• Oil, grease, and toxic chemicals from urban runoff and energy production.
• Sediment from improperly managed construction sites, crop and forest lands, and eroding streambanks.
• Salt from irrigation practices and acid drainage from abandoned mines.
• Bacteria and nutrients from livestock, pet wastes, and faulty septic systems.
• Atmospheric deposition and hydromodification.

The major sources of nonpoint source pollution are agriculture, urban runoff, and habitat modification. In agricultural areas, nonpoint source pollution comes from farm fields, livestock facilities, and fertilizer and pesticide use. In urban areas, it comes from streets, parking lots, and storm drains. Habitat modification includes the channelization of streams and disturbance of riparian corridors.

Frequently asked questions