Water Quality

Water is one of the world's most crucial natural resources. Society uses water across the globe for a variety of purposes. In fact, the average person uses over 145 litres of water every day, which is enough to fill nearly two full-size baths. Water quality standards are highly important; low water quality issues leads to negative impacts on the natural environment, wildlife, and human health. So, what are the main pollutants found in water, what are the 5 indicators of water quality, and what are some water quality examples?

Water Quality Issues

Humans use water for several purposes. From drinking water, cleaning, cooking, and agriculture to a range of industries including generating energy for electricity, water has great significance throughout society, ultimately for the survival of all living things.

Fig 1. Water

Water quality can be affected by several factors, including climate, precipitation, soil and sediments, vegetation, and human activities. However, the main contributor to the lowering of water quality is human activities. These activities include agricultural activity and other heavy industries including mining and urbanization. Toxic contaminants, sediments, and nutrients from these industries leach into nearby bodies of water, polluting the water and therefore lowering its water quality. These are issues of water quality.

Water Quality Examples

Water quality is lowered by the number of pollutants found in it. Water pollutants come in all sorts of shapes, sizes, and consistencies. Some pollutants include non-biodegradable plastic, heavy metal, fertilizer, and gases such as carbon dioxide. However, these are just a handful of examples.

Water pollution can be identified as either point source pollution or non-point source pollution. Let's take a look.

Point Source Pollution

Point source pollution is when the source of the pollution can be identified.

This type of pollution is much easier to identify and therefore, easier to eradicate.

Fig 2. Bodies of water can easily become polluted

Non-Point Source Pollution

Contrastingly, if the source of the pollution cannot be identified, it is classed as non-point source pollution (NPS.) Sometimes there can be multiple sources of pollution, and these sources can come from a wide range of locations. This makes it difficult to prevent the continuing contamination of the water.

This type of pollution usually occurs due to precipitation, land run-off, drainage, or seepage. The precipitation or run-off picks up various pollutants, which are eventually deposited into water bodies, such as rivers, lakes, and streams. Non-point source pollution is one of the highest contributing factors to polluting water, impacting the health of humans and wildlife.

Non-point source pollution mostly comes from agriculture, construction, mining, urban activities, and industries such as energy production. Therefore, the types of non-point source pollution include fertilizers, pesticides, insecticides, oil, sediment, toxic chemicals, bacteria, salt, and nutrients. These can all have a significant effect on water quality.

Water and Urbanization

Water quality is a challenge to urban sustainability. Urban environments create large amounts of pollution that can impact not only our air quality but also our water quality.

In urban environments, humans create pollution that enters bodies of water from a variety of sources.

Factories and Power Plants

Water is used in the manufacturing processes of some factories, including oil refineries and paper mills. In this process, the water becomes heavily polluted with toxic chemicals and metals. This water can be found in natural bodies of water after the factories have used it due to dumping or leaching, which causes pollution and the lowering of water quality.

Forestry and Agriculture

Fig 3. Eutrophication.

Mining

Similarly, precipitation and run-off can carry sediments and pollutants from mining sites into bodies of water, lowering the water quality. This can lower the quality of drinking water in a region and seriously affect the health of those living in the local area.

Municipal Wastewater Treatment Plants

Although the aim of these plants is to treat water in order to remove pollutants, high amounts of waste have to be dumped somewhere. This can lower the water quality in other locations. Water treatment plants can also remove helpful bacteria, causing disruptions in to the local ecosystem.

5 Indicators of Water Quality

There are 5 main indicators of water quality. The table below shows these indicators and how they can notify the level of water quality.

Water Quality Standards

Water Quality Standards, or WQS, is a standard of quality expected of water used by society. Bodies of water must meet recognized standards in order to be used by humans, and these standards can range across the world.

In the US, the EPA (Environmental Protection Agency) has a law that approved the conditions of bodies of water. This not only protects human health but also benefits the environment and aquatic life. The quality of water can be measured by either numeric values, or a description, for example, water that does not contain pollutants.

In the UK, the Environment Agency monitors water quality and maintains the standards expected of the UK.

Water standards vary across the world. Additionally, the standard expected of water varies depending on the type of water body and its use. The standard expected of groundwater will not be the same for surface water. This is especially the case for drinking water, as the standards are much higher.

If humans were to consume contaminated water, their health is highly likely to be compromised. Health problems humans can develop from poor water quality include:

• Cholera
• Typhoid
• Diarrhoea
• Hepatitis A
• Polio