Water Pollution


Water is the beginning of life. Especially sweet water, which makes our planet so unique. Life is only possible with its existence and we couldn’t survive without. Only three percent of the water on earth is sweet water (or drinking water), and just one per cent is available for the human beings.

If you think of that fact, there is just one simple conclusion: we have to take care of our ecosystem, specially rivers and lakes.
What we wanted to show in our project is how to care about our water and to indicate the main problem of the topic “water pollution”.

The problem of water pollution in Switzerland

Industrial chemicals, pesticides, drug residues and hormones – in sewage treatment plants (also ARA = Abwasser-Reinigungs-Anlage), is a huge chemical mix. However, many of these substances cannot be filtered out of the water, even if the sewage treatment plants are state-of-the-art.

Thanks to modern analysis methods, even the smallest amounts of substances can be found in the water. Since these toxic substances cannot be filtered out of the water, due to their molecular structure, they pass the sewage treatment plant unhindered and reach the waters and possibly even our drinking water.

Many poisonous substances which are used in agriculture land in the water source: www.lebensmittellexikon.de

A reason, why so much poisonous substances land in water is the dung (Dünger) of the agriculture, which is needed for arable farming (Ackerwirtschaft), but also antibiotics which are given to the animals also lands in the water. None other European country “sprays” more pesticides in agriculture than Switzerland. More than 2,000 tons of toxins land in our fields every year – even though the government wanted to reduce pesticide usage to 1,500 tons by 2005. The goal was never approached.

This big amount of poison in the groundwater (Grundwasser) is not only dangerous for the Swiss wildlife – also humans are threatened with the risk of getting irremediable infections (unheilbare Infektionen).

Excursion at the sewage treatment plant in Wetzikon ZH

The big pumping station at the ARA Wetzikon

The sewage treatment plant of Wetzikon, Canton Zurich, cleans the water of the hole community and the countryside around, which is flowing through the sewage water system. (underground tunnels where the water gets to the ARA). We went for a visit there and had a guided tour (Special thanks to Mr. Bhend).

As well as in the sewage water system, there are also very many pumping stations (installations with whom water can be lifted up) at the ARA Wetzikon, because the landscape is too flat for the water to flow through the hole plant on its own.

This is the first cleaning step of the ARA Wetzikon: heavy solids can settle to the bottom while oil, grease and lighter solids float to the surface.

The hole cleaning-cycle (Ablauf) is very complex, with all its biological and chemical processes (which we can’t explain in detail). It is also a problem, that all the water which comes from rain or from the households can’t be saved for dry phases – when there is much rainfall, everything reaches the sewage treatment plants at the same time. So if the ARA is too small, the polluted water will get back to the nature uncleaned.

A drop of water is in the ARA for about 24 hours, before it is jetted out to a stream. At this moment, the drop of water will never be this clean again, as it is at this very moment.

The sewage treatment plant plans to create a new step during the water-cleaning, that will reduce the problematic micropollutants [Mikroverunreinigung]. But this project will cost around 5 Million Swiss Francs, so it isn’t cheap at all.

Turkey’s Water Potential / Situation

In contrary to the general perception, Turkey is neither a country rich in freshwater resources nor the richest country in the region in this respect.
Turkey is situated in a semi-arid region, and has only about one fifth of the water available per capita in water rich regions such as North America and Western Europe. Water rich countries are those which have 10.000 cubic meters of water per capita yearly. This is well above the 1.500 cubic meters per capita in Turkey.
Another point is that Turkey’s water is not always in the right place at the right time to meet present and anticipated needs. Certain regions of Turkey such as the Black Sea region have ample (reichlich) but unusable freshwater, while some of the more heavily populated and industrialized regions such as the Marmara and the Aegean regions lack sufficient fresh water. Source: Turkey’s Policy on Water Issues

Izmir’s wastewater treatment plant

Since 2000 Izmir has got the Largest municipal wastewater treatment plant in Turkey with a capacity of 4 millions PE (=population equivalents). Get an overview here »
Source: Izmir, Wastewater Treatment, Turkey (wabag.com)

Tips about preventing water pollution

Use fewer chemicals to clean your home
It’s an easy switch that makes a big difference. Using toxic chemicals like bleach and ammonia to clean your home is not only bad for the water supply, it’s not necessary.

Don’t flush medication.
Medication is made with a variety of substances that can be detrimental (schädlich) to the water supply.

Don’t flush trash.
Flushing items that don’t break down, like diapers, wet wipes, and plastic tampon applicators can cause problems in the sewer system (Kanalisation). These items will eventually end up in local streams, rivers and other bodies of water, where they can harm fish and other wildlife. Instead of flushing them down the toilet, throw them away.

Avoid using plastic.
Since it isn’t biodegradable, plastic often ends up collecting in rivers, lakes and oceans when it has nowhere else to go.

Don’t use pesticides (Pflanzenschutzmittel) and herbicides.
These chemicals are sprayed on the surface of the yard, but when it rains they leach deep into the ground and get into the groundwater below.


The team “Water Pollution” went with the “Overfishing” team to the Lake Greifensee where we visited a real fisherman. We thought that he would have also some important/interesting ideas and conclusions about the topic of water pollution.

We were very glad, meeting such an intelligent, pleasant and competent person, who was able to give us some further information about the local water pollution.

Most of the People may think that the Swiss water quality is one of the best in the world. Today it is true that Switzerland might be one of the leaders in this field. But the situation was not always like that in the past.

The fisherman told us that Lake Greifensee had been one of the dirtiest lakes in Europa. The water quality was not good at all. Until the 60’s, the Situation was worrying. The hole waste water of the “Zürcher Oberland” had been flowing uncleaned into the lake. Some races of fish like the powan (Felchen) were threatened to become extinct. The main reason was the farming. A lot of manure and lead (Dünger und Blei) ended up in the lake. Old “sea bears” used to say that the lake stank. But when the first treatment water plants came up, the situation changed dramatically in the 70’s. According to the fisherman “the water from Lake Greifensee is almost drinkable”.

The quality of the water increased extremely the last few years, despite the fact that Lake Greifensee is still one of the dirtiest lakes in the area of Zurich. In summer it can occur that fish have lack of oxygen because of high water temperatures. The reason for that is the past. But the government found a solution to pump air into the sea. Nowadays the life of the animals in the sea is safe.

Such as these experiences are the reason why project work can be funny and interesting.


The problem with water pollution is global. Inventions such as the wastewater treatment plants helped improving the water quality tremendously. Actually, we cannot really sense the negative effects about this topic, but the problem will increase in the future. What we can do is to take care while we do minding about the above described tips preventing water pollution.

For further information

Initiative sauberes Trinkwasser (initiative-sauberes-trinkwasser.ch)
Wasserverschmutzung verhindern (fantacine.com)
Seeverschmutzung Rapperswil-Jona (Zürichsee-Zeitung, zsz.ch)
10 Fakten über Lösungen zur Wasserverschmutzung (fantacine.com)

Thank you for your attention!

Matthias, Jakob, Team Zürich
Senca, Ece, Yagmur, Team Izmir

On-topic posts on dontwastemy.energy
Does the population of Zurich waste too much water?

☷ See the project teams here »
☵ Some words about the contributions »

9 thoughts on “Water Pollution

  1. hello people!

    i was flabbergasted, astonished and shocked reading this article. i felt so many emotions at once and i must say i am deeply impressed by it. the information is useful and simple yet informative written. i now know more about water pollution in different countries. it is very helpful that the article teaches others how to prevent water pollution. i strongly believe that more people should talk about this incredibly important topic, because it affects us immensely and many do not know that.


  2. Love all

    First of all I would like to tell you that your article about water pollution is very well written and interesting.

    I’m deeply impressed!

    I was surprised by some things, especially from the information from the fisherman. I would never have thought, that a lake in our very clean Switzerland was one of the dirtiest lakes in Europe.

    Your contribution really inspires me and I am very motivated to continue to pay attention to the prevention of water pollution. But still I question the fact whether all readers are influenced by this article – I hope so for us and our next generation.

    My thoughts at the end, there is no way around keeping our fellow human beings in mind again and again, tackling the problem now and thinking about our environment every day – everyone can help to preserve our vital element – water!

    Refreshing greetings
    Vanessa Nauer

  3. Plastic pollution on land and sea is a big problem around Izmir specifically in Aliaga. Not only do consumers need to change their behavior, to reduce their single-use plastics – consumers also need to send the signal that they care about the issue, and want the system to change.

    Also, businesses like Petkim will need to do their part, coming up with alternative products and models to allow a low-plastic society to flourish and continue to enjoy modern conveniences. Indeed, many businesses are ready to embrace a bioeconomy.

    But ultimately, it’s up to governments to create frameworks that make change possible. And it’s up to us to demand that.

    Never mind about second Petkim.

  4. Hi guys

    For beginning i would like you to know that it was very interesting to read your text about water pollution. It\’s written in clearly and understandable for everyone and also the structure is build up well.
    I was a bit shocked, when I read the passage of the lake Greifensee, because this is one of my favorite summer destination to spend a great day with my friends. I didn\’t know that this lake is that dirty.
    As well you\’ve mentioned the process of cleaning dirty water but I\’m still not sure how this process really works but I think it would be interesting to know more details about this.
    To summarize, I notice that you invested a lot of time in this article and it end up really nice, keep it up.

    Kind regards,

  5. Thank you for your text. Your post is written very organised and understandable. I didn‘t knew that a drop of water will never be this clean again, as it was after 24 h in the ARA. I think it‘s a great idea to shoot a little film like you did. It must have required a lot of time but it‘s definitely worth it.
    On the other hand you could have used a little more pictures in the text. Thank you for your tips about preventing water pollution. I already tried them in the past few days. I especially like the Experience and the Conclusion. What I don‘t understand is why you only did the quotation marks before but not after the quote.

    Greetings, Pascale

  6. Hey Guys!

    Firstly I want to say that your article about water pollution is great! It has a nice layout and is understandable written. For me the most interesting part was the history about the lake Greifensee. I didn\’t know that before and i think this is a positive change. It is also interesting to see the differences and the commonalities in Turkey and Switzerland.
    It is good to know how each of us can do something against water Pollution.
    Maybe you could write a little bit more about the process of cleaning dirty water.
    I really liked your article!

    Kind regards

  7. Hey Guys 🙂

    First of all I want to say that your article was very interesting to read and I learned a lot of new things. The layout is very nice and inviting. Not only did you give a lot of information, but also references and examples to Switzerland and our daily life.
    What I especially like is that you give advise on how to prevent water pollution and fight against it.
    The part about the history of the lake Greifensee was very surprising for me and I would have never imagined that.
    One thing that you could have focused on more is how exactly the water gets cleaned.
    Thank you for this great article!

    Kind regards

  8. Hey guys!

    Water pollution is a very interesting topic and a running issue all around the world.

    You did a really good job with your introductive statement (referring to \”Water is the beginning of life\”), it draws interest to your essay, which I especially liked a lot.
    I was very surprised about the fact, that none other European country sprays more pesticides in agriculture than Switzerland. This fact made me realize, that our drinking water for example isn\’t probably as clean, as I expected it to be.
    The visit of the sewage treatment plant in Wetzikon was a good reference for your research. But I\’d like to know, what did you guys saw exactly there and what is the status quo of the project (new step during the water-cleaning)?
    Your five tips about preventing water pollution are really helpful, I\’ll try to follow them.
    In addition to the water pollution situation in Switzerland, I enjoyed the part about the setting in Turkey.

    From my point of view, your text is limited to the minimum. We don\’t get any further information concerning the origin, the distribution (around the world) and the approach to solve the problem. The design, layout and media is nice, but there is still room for improvement. I suggest to dive deeper in to the topic water pollution, because there is a lot more to write about. Additional you could do a project, for example a mechanistic model of the water cleaning process.

    Kind regards,

  9. Hello Team Water Pollution

    At the present time is Water pollution a vital subject that needs to be disseminated!
    Just the fact that only three percent of the water on earth is drinking water, and just one percent is available for the human beings already explains allot.
    In my opinion the people must be better informed about such an important topic otherwise the future of our next generation will be in danger. Being informed is one thing, but implementation also plays a major role. In this case the big companies should step in with their capital and power and do something for the world. In the end, all the money does not pay them when the human race disappears…

    Kind regards
    Victor Füllemann

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