EU Urban Wastewater Directive adopted in April
16. April 2024
The understanding of water vs. reality
Get up in the morning, drink a glass of tap water, make coffee or tea, take a quick shower, brush your teeth, do your laundry, cook and so on. We need water - for everything. Water is a fundamental and natural part of our lives. Without clean water, we cannot live, we cannot survive. But the image of crystal clear water is becoming clouded. More and more pollutants, more bad news. If we only look at German households, around 36 per cent of drinking water was used for bathing, showering and personal hygiene in 2023. According to Statista, around a quarter of drinking water went through our toilets. Drinking water is a consumer good. And not just for private households. After all, in just under 30 years of recording values, we have managed to reduce consumption across society through sensible measures - from 147 back then to around 121 per inhabitant (based on Germany) today. But what does the future hold?
The importance of the water cycle
A well-managed water cycle underpins progress across the 2030 Agenda for Sustainable Development, particularly in relation to hunger, gender equality, health, education, livelihoods, sustainability, and ecosystems.
Water is also at the centre of climate change adaptation, as it is the critical link between the climate system, human society, and the environment. Without adequate water management, there is likely to be increased competition for water between sectors and an escalation of water crises of various kinds that will trigger emergencies in several water-dependent sectors. Furthermore, the physical world of water is closely linked to the socio-political world, as water is often a key factor in addressing risks such as famine, epidemics, inequalities, and political instability.
But water has so many impacts on our lives, in all directions. From floods to water scarcity, from health issues to economic life. Water is one of the most important drivers of our world's activities.
However, the question that must be asked in the face of increasing reports of drinking water shortages and falling groundwater levels (also in Germany) is: What value do we place on water?
The short answer: too little importance or too little value. We are spoilt in Germany. Water, especially our drinking water, is still regarded as the safest food in Germany, despite some concerns. Drinking water quality is monitored throughout the country. And if there are regional problems, we are at least given the feeling that the authorities are doing everything they can to get the problems under control again.
But nobody really thinks about wastewater, do they? Or have you ever asked yourself in the morning, when the wet wipe disappears in the toilet together with the cotton bud, what challenges our wastewater treatment plants must overcome day after day? Not to mention the additional pollution introduced by industry. Many people realise that our wastewater is an important resource because it leaves the sewage treatment plants in its purified form for rivers, lakes and the sea and thus provides the basis for our drinking water production. However, very few people realise that the treated wastewater from wastewater treatment plants is not yet of drinking water quality. In this context, the keywords self-cleaning capacity and dilution factor are often used. But what does this actually mean? And what does this mean for the purification performance and our water quality of the future?
The future is no longer so rosy: the cocktail of pollutants is becoming more complex and pollution is increasing
For far too long, we have relied on the self-cleaning capacity of the environment in the area of water and wastewater. By definition, self-purification is the ability to self-regulate environmental activity through a series of specialised mechanisms to reduce external pollution or to convert toxic substances into non-toxic substances. Basically, the aim is to restore the original quality of the water. Among other things, hydrodynamic, physical, chemical, biochemical, etc. processes that take place in the water environment help here. processes that take place in the water environment.
Excursion into the world of water types
The hydrological cycle comprises three sources of water: Rainwater, surface water and groundwater.
- Rainwater: In terms of hygiene, microbiology and chemistry, rainwater is the cleanest, the only disadvantage being that the salt concentration is too low.
- Groundwater: In terms of hygiene, groundwater is inferior to rainwater, but cleaner than surface water. In many cases, it does not need to be treated and can still be used. Groundwater is formed when surface water seeps into the ground. The physico-chemical composition of groundwater depends on the geological structure and the composition of the surface water, and the bacterial contamination of groundwater varies greatly. As a rule, groundwater close to the surface is more contaminated than deep groundwater. The deeper it penetrates into the ground, the fewer bacteria are present, as the upper soil layers can retain most bacteria. Many data show that bacteria in slurry pits cannot penetrate deeper than 30-40 cm into the soil. However, sometimes bacteria are detected at a depth of 1.5 metres or more resulting in contaminated groundwater.
- Surface water: When rainwater falls on the ground and flows into rivers and lakes, it is referred to as surface water. Surface water is the dirtiest water in terms of microorganisms, organic and inorganic matter. Because surface water is rich in nutrients, it is a good environment for the growth of many microorganisms, including fungi and lower animals.
If we take a closer look at the self-purification process, we can see that it involves two basic processes:
- the process of mixing and dilution between wastewater and source water;
- the process of mineralisation of organic substances with the participation of microorganisms and aquatic organisms.
In practice, these two processes occur simultaneously, but their intensity depends on the location of the wastewater discharge, hydrodynamic factors such as velocity, water level, current, roughness coefficient, turbulence diffusion, river and lake morphology, current meanders, etc. and other environmental conditions. Thanks to the two processes mentioned above, the concentration of pollutants introduced into the water source decreases to a certain level after a certain period of time. The end result of these processes is the partial or complete restoration of the water source to its original state.
If the inputs become more variable and at the same time the wastewater treatment plants are no longer able to adequately clean the entire cocktail of different dissolved and undissolved organic and inorganic pollutants, including microplastics, then the discussion of an expansion quickly comes up. In most cases, the keyword here is 4th purification stage.
Fourth purification stage and then?
If you don't know what to do next, new processes are often planned instead of scrutinising old processes or carrying out source analyses. We start by analysing the sources in the field of microplastic analysis. We are searching for the hotspots, sampling wastewater treatment plants, industrial process streams, and water bodies, and providing a comprehensive, data-based overall picture. We are trying to do the same in the field of micropollutants for 40 years. But coherence of data, comparative data, and multivariable data analysis are all missing.
Instead, holes have been dug in many places and a fourth cleaning stage has been implemented for the removal of micropollutants without knowing exactly what they actually want to remove, and without analytical monitoring and control instruments. Today, we know what we have failed to do for the past 40 years. The loads are variable, the chosen analytical methods are inadequate in continuous process streams and with the large volumes of water that the wastewater treatment plant deals with on a daily basis. The results hardly stand up to discussion. The question marks are getting bigger and bigger, while the pollution of water bodies continues to increase, as a new study by the Federal Environment Agency shows.
But what happens when the wastewater treatment plants reach their limits?
The new EU Urban Wastewater Directive was adopted at the beginning of April. However, there are hardly any technological or socio-political answers as to how to reduce the complex pollutant loads in the short and long term. However, there is still a chance and a ray of hope. The big stage could overtake Germany and Europe and act as an accelerator.
The UN Sustainable Development Goals: The link and the opportunity. Water features in every single Sustainable Development Goal and in our non-profit corporate strategy. Did you know that?
But where are the levers, where are the opportunities? Where can we start to position the topic of water in a meaningful, appreciative and sustainable way and highlight it in the context of the UN Sustainable Development Goals? And of course there is also the very important question: What can we do?
Answered in our words and with our levers: We need more detect | remove | reuse. With transparency and open communication and the identification of hotspots of pollution and entry paths, we can effectively protect the waterways and our wastewater treatment plants, act at an early stage according to the precautionary principle and protect our environment. Sounds like dreaming? Our projects and feasibility studies already show that it is possible. In our publications, we provide the data, peer-reviewed and for imitation. The blog is our communication platform. But we are repeatedly thwarted in our activism. This is because as a non-profit organisation, we are unable to access some funding sources because we are accused of thinking uneconomically, or because t sometimes takes over a year for the first funds to flow. For people like us, who would rather deliver solutions and impact yesterday than today, these are incredible hurdles. But we can overcome them together – with you. Because you can become an impact accelerator at Wasser 3.0 as a donor or sponsor. With your financial support, we can do it. For more water without microplastics. For more technological innovation transfer. For more sustainable education.
