Why filter water (again)?

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Updated on: 12/03/2020

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There are many reasons to filter water. On the one hand, it may contain ingredients that lead to cloudiness or impurities, impair taste/odour and generally impair the ability to enjoy. It could also contain pollutants or pathogens.
The word "again" in brackets refers to the fact that most consumers obtain their tap water from a drinking water supplier where it has already been purified and treated in the waterworks. But firstly, when treating water, the drinking water supplier only considers the 50 or so most important ingredients that are explicitly mentioned in the German Drinking Water Ordinance and for which limit values have been set. Secondly, the drinking water then travels another distance, usually several kilometres, in the public pipeline network and then in the domestic pipeline network before being consumed. On this long way new impurities can be added.
However, there are also consumers who obtain their drinking water locally from their own wells. The current ingredients are usually completely unknown or are rarely monitored. In order to be able to ensure optimum drinking water quality, it is therefore obvious to filter the water before consumption.

Main reasons

  • It is polluted by organic substances that disturb the taste, so you may not like it.
  • It is contaminated by many substances that are NOT covered by the Drinking Water Ordinance. Like residues of pharmaceuticals, pesticides, asbestos fibres, microplastics, industrial chemicals, etc.  
  • It is contaminated by bacteria that have slipped through during processing or were introduced later. There are press reports of bacterially contaminated water almost every week, and residents are asked to boil their water, often for several weeks.  
  • It is contaminated by heavy metals such as lead or copper, which have accumulated in the water on the way through old water pipes to your tap.  
Comparison dirty water vs. clean water

Drinking Water Ordinance (TrinkwV)

The Drinking Water Ordinance in its original version dates back to 2001, but has since been revised and supplemented several times, most recently at the beginning of 2018. In view of new medical findings and improved test methods, the regulations for ensuring drinking water quality in Germany have been gradually renewed in recent years. The task of the TrinkwV is to ensure and improve the quality of drinking water in Germany. The Drinking Water Ordinance is based on the EU Drinking Water Directive and the German Infection Protection Act. It defines the quality of drinking water with regard to human health as follows (paragraph 37, section 1): "Water intended for human consumption must be of such quality that its consumption or use is not likely to cause harm to human health, in particular through pathogens".

The Drinking Water Ordinance regulates the quality of drinking water, its treatment, the obligations of water suppliers and the monitoring of drinking water. Reference is made to generally accepted technical rules as well as national and international standards for the professional production, treatment and distribution of drinking water. If water suppliers and, in the further course, also landlords/house owners demonstrably observe these technical regulations and instructions, they ensure to a sufficient extent "that the drinking water arriving at the consumer's premises meets the requirements of the Drinking Water Ordinance".

But does this also mean that the tap water reaches the consumer in perfect condition? This is a controversial issue. The Drinking Water Ordinance (TrinkwV) is divided into chemical, microbiological and radiological requirements with binding limit values for a range of about 50 possible pollutants. The drinking water is permanently checked for these in the approximately 6,000 waterworks in Germany and treated accordingly. In practice, the treated water is considered to be easily drinkable and digestible. One reads again and again that German drinking water is the most controlled foodstuff with excellent quality.

More and more pollutants are entering the water cycle through industry, agriculture, environmental influences and also us humans, which are not regulated and tested at all by the Drinking Water Ordinance. In addition to the 50 controlled pollutants, there are a large number of other ingredients that nobody monitors, including fertilisers, corrosion and pesticides, trihalomethanes, asbestos and residues of pharmaceuticals, hormones, plasticisers, and viruses or heavy metals.

Up to 100,000 impurities and pollutants can occur in our drinking water. Renowned institutes and analysts such as Ökotest, Stiftung Warentest, Frontal 21, etc. regularly detect hazardous ingredients and pathogens in German drinking water. The EU has threatened Germany with fines because far too high concentrations of fertilizer residues are contained in the drinking water of some regions.

Service water / industrial water

Service water is water that has not been supplied by public drinking water supplies or whose suitability as drinking water for human consumption is not given or proven (rainwater, grey water). Service water includes all water used for purposes such as flushing toilets, watering or washing laundry. Service water is not subject to the Drinking Water Ordinance, but should meet certain hygienic standards. In order to reduce drinking water consumption, it sometimes makes sense to set up a separate service water supply when new houses are built or modernised. 

From the waterworks to the tap

Even if the water supplier feeds the tap water into the pipeline network in perfect "fit for consumption" condition, it is exposed to numerous possibilities of renewed contamination on the long way from the waterworks through miles of pipes to the domestic tap. The public water supply network in many places in Germany is old and in need of renovation. And even on the last few metres inside your own building, the possibility of additional contamination cannot be ruled out at all. Dissolved heavy metals from very old copper or even lead water pipes or germs from dead strands and the biofilm contained in pipes can greatly reduce drinking water quality. If the water remains in the pipes for a long time, this is not beneficial either. The Drinking Water Ordinance does not apply here and conventional house entrance filters only remove larger dirt particles (such as sand) from the water. We therefore recommend a filter for drinking water directly at the point of use, i.e. just before it is consumed.

Water treatment plant with sewage treatment plant and storage tanks

Transport and risks in the distribution network

Every German citizen consumes around 127 litres of water every day (as of the end of 2018). This means that we use the least amount of water in comparison with the rest of Europe. There are more than 6,000 public drinking water suppliers in Germany, and more than 90% of the water supply is in municipal hands. After treatment in the waterworks, drinking water has to travel many kilometres before it flows out of the tap. 50 kilometres and more can lie between the waterworks and the household.

The distribution network in this country is estimated to be over 500,000 kilometres long. All the German water pipes laid together on the equator would therefore go around the world more than eleven times. Approximately 5,000 million cubic metres of drinking water flow through water pipes in this country every year - in litres, that's a "5" with 12 zeros. More than 99 % of the population in Germany is connected to a public drinking water network.

"The drinking water treated in the waterworks reaches the consumer's tap via a water distribution system that is sometimes very complex. During this transport, the water comes into contact with a large number of different materials and components. These can release substances into the drinking water which change the smell or taste of the drinking water, have a health relevance or lead to a proliferation of microorganisms and thus possibly also of pathogens".

Drinking water undergoes a more or less strong change in its composition when it is distributed to consumers via fixed pipelines. This change in water composition after treatment is due to interactions with surfaces in contact with water, such as pipe materials, both in the public distribution networks (problems: iron, asbestos cement, biofilms). The demands on the treatment technology have increased in recent years because the distribution networks have grown and this has led to longer residence times of the treated drinking water from the waterworks to the consumer. Besides pathogens, toxic chemical substances in drinking water also play a role.

While microbiologists assumed just a few years ago that the amount of germs from public supply networks was manageable, it is now known that drinking water contains between 40,000 and 200,000 germs per millilitre at the point of transfer from the public mains to a building. Most of these bacteria come from natural sources. But even in the distribution network on the way to the consumer, with every milliliter of water from the city network, up to 200,000 germs get into the pipe networks of buildings. In addition to the type of raw water, the length of the pipes between the waterworks and the consumer also plays a role in the degree of contamination. Temperature and nutrient supply are decisive for the reproduction of microorganisms.

Old pipes in the house

"The drinking water supplied by the water supply company is almost always of impeccable quality in Germany. But in drinking water installations in buildings (...) the water quality can still be changed decisively up to the tap.

Especially in old buildings, old water pipes can pose a high risk to water quality and thus to health. This danger is usually underestimated. But if you regularly ingest heavy metals such as copper or lead or bacteria and germs with your drinking water, this can have considerable health consequences. Often complaints, symptoms and illnesses are associated with the contaminated tap water only late or not at all. Especially for babies, children and immunocompromised people, dangers lurk here.

Until the early 1970s, it was common practice to use lead pipes for drinking water installations in houses. Since then, however, it has been known that the toxic lead dissolves and gets into the water. Landlords are therefore obliged to ensure that the lead limit value according to the Drinking Water Ordinance is complied with. If old lead water pipes are still installed in the house, tenants have the right to have the affected pipes renovated. A water analysis for private households can show whether renovation is necessary.

While lead lines have been banned since the 1970s, copper lines are still frequently used today. But copper also releases traces into drinking water, especially when the pH value is below 7. Copper can cause liver damage, especially in infants and young children.

A further problem that negatively influences the quality of drinking water are branched pipe systems with dead pipes, which are altered by conversions and extensions. This also applies to rarely used water pipes in which the water stagnates. The longer water remains in the pipe, the more substances it absorbs from pipes and fittings. Nickel from the alloys gets into the water from rarely used taps.

If the water temperature in the system is also higher than 20 degrees, this promotes the formation of bacteria and germs, especially legionella. These multiply explosively in lukewarm water. Legionella and other bacteria may find excellent conditions for multiplication here. The danger is not only in the hot water pipe, but especially in old buildings also through a badly insulated cold water network, which is heated by a hot water pipe located near the building. You notice this when the water from the cold water pipe comes out of the tap relatively warm at the beginning.

Drinking water hygiene

Hygienic, i.e. clean drinking water free of pathogens, is a human right, although it is still far from being taken for granted worldwide.

Colloquially, hygiene is equated with cleanliness, but it is mainly about maintaining health and preventing diseases and infections. The importance of drinking water hygiene became clear in 1892, when one of the most serious cholera epidemics in Germany broke out in Hamburg, resulting in more than 8,000 deaths. Even then, Robert Koch's research had already revealed the connections between poor drinking water, lack of or poor wastewater disposal and pathogens. They led to the establishment of a drinking water treatment plant according to strict rules.

Here in Germany, where more than 90 percent of consumers are connected to the public drinking water network, drinking water hygiene depends above all on careful treatment and the condition of the drinking water network and domestic installations. Basically, drinking water is never sterile, but contains varying concentrations of organic substances and microorganisms. When water in drinking water pipes stagnates and/or heats up over a longer period of time, these microorganisms multiply. Therefore drinking water should always flow. Studies have shown that the majority of drinking water installations, especially in the public sector, do not always meet the hygienic and regulatory requirements. Old pipes, contamination due to damage, unintentional heating, etc. lead to deficiencies in drinking water hygiene.

In order to be able to ensure hygienically safe drinking water despite these possible impairments, (re)treatment at the point of withdrawal is the simplest method. Drinking water filters from Alb Filter offer a cost-effective and efficient solution.

Healthy tap water?

Many consumers ask themselves the question whether drinking tap water is healthy or whether they should not prefer bottled or mineral water. In general, it can be said that drinking water is healthy as long as it does not contain harmful impurities and pollutants that have harmful effects on humans.

According to the Federal Environment Agency, tap water is the most strictly controlled foodstuff and therefore of excellent quality. The German Drinking Water Ordinance contains limit values for about 50 different ingredients, which are strictly controlled. However, environmental associations criticise that many other chemical and microbiological impurities in tap water are not taken into account at all and are therefore not controlled. These include drug residues, fertilizers, pesticides, hormones, plasticizers, microplastics, etc., which are not removed by waterworks at all or only in a makeshift way. This way the impurities remain in our tap water.

Many people prefer bottled water because they believe it does not contain any impurities or pollutants. Since mineral water is extracted from underground water deposits at greater depths, it seems to be better protected from contamination. However, pollutants, residues of pesticides and germs are also regularly detected here. In addition, straight water from plastic bottles can contain plasticizers and microplastic particles.

The ideal method is a treatment at the point of extraction, as offered by Alb Filter's filter solutions.

Cost aspect

In Germany, clean drinking water in unlimited quantities from the tap is regarded as a self-evident standard. And compared to bottled drinking water, you can get it at an unbeatable price, even if it can vary depending on the region and the supplier. On average, a cubic metre of water, i.e. 1,000 litres, will cost about EUR 2.36 in 2019, including sewage charges. In addition, there are basic charges by the utility company, so that about 0.4 cents will be charged per litre.

This is of course economically unbeatable. Bottled water costs a multiple. You can get cheap mineral water from 13 cents per litre (e.g. Aldi), i.e. 32 times more. Well-known water brands (e.g. Apollinaris at REWE) offer their bottled water for about 60 cents per liter, which is 150 times more expensive than tap water. Even if tap water is filtered to prevent pollutants and germs before it is consumed at the point of use, for example with Alb Filter solutions, the cost of this is still far from the price of bottled water in the same quantity. Moreover, unlike bottled water, tap water does not cause any packaging waste and there is no need to worry about transport. For mineral water, additional costs for packaging and transport are included.

Tap water versus mineral water

The fact is: buying bottled water is neither environmentally friendly nor economical. Regardless of aspects like taste and hygiene, bottled water has a miserable ecological footprint. Very few waters are still filled in returnable bottles today, and the proportion of returnable glass or PET plastic bottles has fallen from over 90 percent in the 1990s to just under 40 percent today. By contrast, 21 billion disposable plastic bottles are bought in Germany every year, most of them filled with mineral water. Aldi and Lidl now sell every second bottle of water in Germany exclusively in disposable bottles, and Coca-Cola is also increasingly switching from reusable to disposable bottles in Germany.

The production of plastic bottles requires fossil raw materials, and they are also used for filling and transporting the bottles to the supermarket. The subsequent disposal of the plastic bottles has an additional negative impact on the environment, as disposable bottles are now widespread and therefore represent a particular burden on the environment. And this also has consequences for our climate. According to Deutsche Umwelthilfe, 1.25 million tons of CO2 could be saved by refillable bottles alone. The new packaging law has the goal of increasing the overall reusable quota to 70 percent from 2021.

But if every consumer were to drink tap water in plastic bottles instead of mineral water, the amount of CO2 saved would be much greater. In comparison, tap water has a very low CO2 footprint. Although drinking water treatment also costs energy, it is relatively inexpensive. According to a study by the ESU Services Institute, still mineral water in (disposable) bottles has a 90 to 1,000-fold higher environmental impact compared to tap water. The exact height depends on the distance that the water has to travel to the end user.

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1. figures according to DVGW
2nd "Water Management in Germany. Grundlagen, Belastungen, Maßnahmen", Federal Environment Agency, Oct. 2017
3. Köster et al, Water Supply Zurich, Aqua & Gas No. 5, 2012
4 "Water Management in Germany. Grundlagen, Belastungen, Maßnahmen", Federal Environment Agency, Oct. 2017