How water purification helps (or harms) the environment – The Facts!


If you are interested in water purification then you are probably also interested in looking after the environment. You may be surprised to discover that while many water purification methods help the environment, many home systems can actually harm it, and it all depends on the method.

Home water purification systems are often bad for the environment because of high electricity use, cartridge replacements and water wastage. However, water treatment plants remove the need for bottled water consumption and are good for the environment. Wastewater treatment plants are also good as they treat our sewage before returning the effluent to the environment.

Given that water purification can both help and harm the environment this article goes in-depth into which methods are good for the environment. So, keep reading to discover the environmental pros and cons of both the different options we can use at home and commercial sized plants, and most importantly which home water purification method is best for the environment.

When water purification helps the environment, and when it harms it

Water purification can either help or harm the environment. Drinking water treatment plants (Public Water Systems) and Wastewater treatment plants can help the environment. While home water purification methods affect the environment differently.

Details on how each water purification type affects the environment are provided below.

Home Water Purification:

Some people choose to purify their tap water at home. This may be due to local contaminants affecting their water quality, such as lead in the pipes, or to improve the taste of their water. The use of home water purification systems can have a big impact on the environment with the following factors to consider:

  • The production, testing and transport of a new water purification system
  • The entire life-cycle of its use, including servicing and consumables (e.g. cartridges)
  • The end-of-life disposal of the system
  • Total energy consumption (carbon footprint)
  • Water usage
  • Component composition (e.g. plastic)

Home water purification systems are so complex there is more information about each method later in this post.

Municipal Drinking Water Purification:

Public Water Systems treat our drinking water so we don’t need to buy bottled water. Without the Public Water Systems purifying our tap water and making it drinkable everyone would have to buy bottled water. Imagine how much plastic would be generated and end up in landfill.

Water purification really helps the environment because we are using less plastic, and since plastic is made from fossil fuels that is a big positive!

Our drinking water may be sourced from surface water (e.g. rivers) or groundwater. The EPA makes sure that all drinking water is not only safe for us to drink, but also safe for the environment too.

Some cities, such as San Diego, also use desalination to purify their drinking water. Unfortunately, desalination is not as good for the environment as the Public Water Systems methods of coagulation, flocculation, filtration and disinfection.

Wastewater Purification:

Wastewater purification has a massive positive impact on the environment. In fact, the USGS says purifying wastewater is

“a matter of caring for our environment and for our own health.”

United states geologic survey

Purifying our wastewater makes sure that none of our toilet and septic waste enters the environment. Wastewater contains dissolved and suspended contaminants, and not just the sludge from our toilets! Wastewater can have wood, rocks and even dead animals in it! Keeping our wastewater from entering of the environment is vital for maintaining healthy fish and wildlife habitats.

Wastewater treatment plants remove the solids before aerating the putrid sludge to get rid of all the nasty smelling gases. The remaining waste is then separated, with a thickened sludge removed from the wastewater. Amazingly, this sludge can be used as a fertilizer, preventing it from entering our waterways as contaminated waste.

The remaining water is then purified until it is safe for the environment and released as “effluent”. Effluent is so clean that it can be released into our waterways, or even used for irrigation!

Negative impacts on the Environment from Water Purification

Every water purification method has some negative impact on the environment, but the good often outweighs the bad, such is the case for Public Water Systems and Wastewater treatment plants. Check out the graph below for a summary of the negative impacts.

Which home water purification method is best for the environment?

Purifying water at home stops us from buying bottled water. This clearly helps the environment, because we are using and wasting less plastic. However, there are different ways to purify water at home, with pros and cons for each method.

While no method is perfect, it may be surprising to discover that filter pitchers come out on top when analyzing the negative environmental impacts. Check out the advantages and disadvantages for each method below.

Negative Impacts on The Environment from Home Water Purification

The environmental impacts of filter pitchers

Advantages

Filter pitchers (or jugs) are a great way to treat water and are easily available. The main advantages of filter pitchers are that they do not waste water and do not use any electricity.

Disadvantages

Unfortunately, nothing is perfect. Not only do filter pitchers not completely purify water, as they leave many unfilterable contaminants in the water, but they actually use a large number of consumables. Filter pitchers need their cartridges replaced regularly, meaning more plastic is being made, used and discarded. More plastic is never good for the environment!

The environmental impacts of distillation

Advantages

To be honest the distillation process by itself doesn’t really have an advantage when it comes to the environment. However, compared to filter pitchers, distillation is better at purifying water and doesn’t use cartridges, meaning it is better for the environment when it comes to consumables.

Disadvantages

While distillation is great at purifying water, it is not so great for the environment. The distillation process requires large amounts of energy and water to produce clean drinking water. Electricity is used to heat water above boiling point and then uses more water to cool and condense the water vapor to make it ready for drinking.

Distillation also requires cleaning with some harsh chemicals, such as hydrochloric acid (HCl), to clean away the contaminants that were removed from the water and have collected in the boiling pots.

The environmental impacts of reverse osmosis

Advantages

The best part about using reverse osmosis in the home is that it doesn’t use electricity to treat water; it just uses water pressure to remove disease causing organisms and chemical contaminants. Not needing electricity is a big plus for the environment!

Disadvantages

Reverse Osmosis unfortunately wastes a lot of water. According to the EPA reverse osmosis typically uses 3 times the amount of water that they treat. But perhaps worse for the environment is the number of consumables a reverse osmosis system uses. The sediment and carbon filters need to be replaced regularly, as does the semi-permeable membrane.

All of this adds up to more plastic and ultimately more garbage in our environment.

How desalination (water purification) plants are bad for the environment

There are 2 main ways that desalination plants purify water: Thermal processing or Reverse osmosis.

Thermal processing uses heat, much the same way that distillation does, to purify water. While reverse osmosis uses pressure to push the water through a membrane, leaving contaminants on one side, and clean drinking water on the other.

Because each process is so different, they have their own pros and cons (See the list below for more information).

Irrespective of the processing method, all desalination plants harm the environment in two big ways.

  1. They produce large amounts of toxic brine, contaminated salt-water, and unfortunately this brine is pumped out into the world’s oceans.
  2. They kill billions of fish annually through the desalination plant’s intake mechanisms. As the plant’s draw in water, they also draw in marine life.

The environmental impacts of desalination by thermal processing

Advantages

Unfortunately, thermal desalination does not have a good impact on the environment.  However, it does provide millions of people worldwide with drinking water, and that must count for something!

Disadvantages

In thermal processing, desalination plants produce thermal pollution. This reduces water quality in the environment. According to research published in the Environmental Monitoring and Assessment Journal thermal pollutants increase seawater temperature, salinity, water current and turbidity.

The environmental impacts of desalination by reverse osmosis

Advantages

Desalination by reverse osmosis has no positive effect on the environment. But like thermal desalination it does provides drinking water to people all over the world.

Disadvantages

Unlike home reverse osmosis systems that use natural water pressure, the large commercial plants use vast amounts of energy to create enough pressure to push salt water through the membrane that cleans the water. National Geographic says that a

“typical plant takes an average of 10 to 13 kilowatt hours of energy per every thousand gallons processed”.

national geographic

That is a lot of fossil fuels being used to purify water!

How water purification after disasters (natural and man-made) helps the environment

Natural disasters, such as hurricanes and floods, and man-made disasters, like chemical spills, can harm the environment. Natural disasters can result in vast amounts of wastewater entering our rivers, lakes and oceans.

Think about all the waste from our toilets and septic systems contaminating the environment!

Cleaning and purifying waters following disasters helps the environment in a big way. While big organizations and the government look after the large-scale clean up, we can help by making sure we clean up after disasters when they affect our homes. Making sure that more contaminated waters or waste do not go into the environment.

The Center for Disease Control (CDC) has some great tips for cleaning up after a disaster and can be found here.

Related Questions

Are Water Filters Bad For The Environment?

Water filters degrade the environment through increased landfill waste from filter cartridge replacements. However, water filters are far less damaging to the environment than bottled water.

Are Water Bottles Good For The Environment?

Plastic water bottles are bad for the environment, they do not biodegrade, require a lot of energy to manufacture and are made from fossil fuels. However, reusable water bottles are good for the environment by reducing our consumption of bottled water.

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