European Drinking Water Directive – An Overview of the New Drinking Water Standards

julian-renpenni · ‎03-07-2022

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I don’t know about your experience, but every time I travel abroad, I realize that tap water isn’t the same in different countries. I still wonder each time I smell chlorine or other odor in my glass, is the water safe and what made the treatment necessary? Even in my home country Germany where tap water is considered safe to drink, I sense different water qualities in the different regions. Most people living in Europe enjoy simple and easy access to high-quality water. Almost all drinking water, provided by major suppliers, is safe to drink across the EU. This is in large part thanks to European environmental legislation, supported by EU funding.

New rules on drinking water

In December 2020, the European Parliament formally adopted the revised version of the European Drinking Water Directive, introducing new minimum requirements for the quality of potable water. The new Directive will guarantee safer access to water for EU members. At the same time, it will ensure the highest standards in the world for drinking water.

The revised version of the Drinking Water Directive entered into force at the start of 12 January, 2021, and Member States will have two years to transpose those guidelines into national legislation. The new rules update quality standards and introduce a risk-based approach, including an obligation for Member States to improve or maintain access to safe drinking water for all, with a focus on vulnerable and marginalized groups. The European Parliament also reduced the limit values for essential parameters and introduced new limit values for substances hazardous to health based on a World Health Organization (WHO) study. New substances will be placed on a watch list. In addition, around 35 more substances have been identified for further investigation, including microplastics, pharmaceutical products and endocrine disruptors. The aim of the watch list is to identify potential risks to potable water at an early stage and to maintain drinking water quality by modifying the treatment process.

In this blog post, I highlight the most important chemical parameters and their revised limits according to the directive of the European Parliament and of the council.

Disinfection byproducts – the chlorine smell of water

Chlorine is the most widely applied disinfectant, added to water as chlorine gas, calcium hypochlorite or sodium hypochlorite. For decades, chlorine has played an important role in water treatment. The advantage of chlorine is that is can be easily produced and is relatively cheap. Most European countries, therefore, applied drinking water disinfection at the end of the 19^th century or the beginning of the 20th century. The presence of disinfection byproducts (DBPs) in drinking water, as a result of water treatment, is an emerging health concern. DBPs come in many classes and are chemically diverse, making them challenging to monitor. To date, over 600 DBPs have been identified. Trihalomethanes (THMs) and haloacetic acids (HAAs) have received the most attention and been subject to the most regulation. While THMs limits remained unchanged, HAAs parametric values were renewed. According to the regulation, the sum of the nine chlorinated and brominated HAAs is now set to limit of 80 µg/L. WHO further recommended including chlorate (ClO3) and chlorite (ClO2) as new parameters. Both are predominantly disinfection byproducts from hypochlorites. The Commission, therefore, set the value for both at the stricter level of 0.25 mg/l, which is around three times lower than proposed by the WHO.

Learn more about disinfection byproducts analysis and HAA analysis workflows.

PFAS compounds – the emerging environmental concern on a global scale

PFAS (poly- and perfluorinated alkyl substances) compounds are a particularly nasty class of substances. PFAS is a generic term for a large group of about 4,700 widely used, man-made chemicals that accumulate over time in humans and in the environment. They are extremely stable (hence the nickname “forever chemicals”) and at the same time spread very easily. PFAS have been used in firefighting foams, nonstick metal coatings for frying pans, paper food packaging, creams and cosmetics, textiles for furniture and outdoor clothing, paints and photography, chrome plating, pesticides and pharmaceuticals. As a result, they contaminate air, water and soil quickly and over the long term. PFAS are associated with diseases of the endocrine system, reproductive organs, and immune system, as well as cancer. The new Drinking Water Directive introduces for the first time a limit value for the 20 most important of the approximately 4,700 different substances. The proposal is to regulate the group of PFAS, as defined by the OECD, and to suggest values of 0.1 μg/L for individual PFAS and 0.5 μg/l for PFASs in total. Over the next three years, the Commission is to develop a method for measuring all PFAS.

Find out more about solutions for PFAS testing and PFAS workflow applications.

Lead and chromium – the toxic kind of heavy metal

Many have known for years that heavy metal lead is harmful to health. It is by far the substance with the greatest negative health effects in drinking water. However, lead pipes were installed in certain regions until the 1970s, putting everyone — especially infants, small children, and pregnant women — at high risk. Due to its high toxicity, the limit value of lead for drinking water has been lowered more than once in the past decades. The historic value of 40 µg/L, which was still valid in the 1970s, was lowered to 25 µg/L in 2003, to 10 µg/L in 2013, and was again reduced to 5 µg/L with the new Drinking Water Directive. This reduction was a core demand of the European Parliament and was opposed by member states for a long time. However, the Commission proposed lowering the value 10 years after the entry into force of the Directive. During this transitional 10-year period, the current value of 10 µg/l will be maintained.

Learn how to analyze toxic metals contaminants in water.

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Microplastics everywhere ...

Microplastics are small pieces of plastics, usually smaller than 5mm. A growing volume of microplastics is found in the environment, including the sea, and in food and drinking water. Everyone knows the images of huge areas in the oceans and beaches covered in plastic bags, plastic bottles and other single-use plastic items and their final destination as floating trash all around the globe. Once in the environment, microplastics do not biodegrade and tend to accumulate. Microplastics will be on a new watch list, though risks posed by microplastics and their presence in the environment, drinking water and food must be explored further. This success of the European Parliament allows Member States to take preventive measures to reduce microplastics if suppliers find too much microplastics in the drinking water. However, detection and determination of microplastics is a complex analytical challenge.

Find out more about microplastics analysis with spectroscopy and mass spectrometry.

Endocrine Disrupting Chemicals – the fake hormones

Endocrine disrupting compounds (EDCs) are an environmental contaminant of growing concern, which undermine the safety of drinking water. According to the US Environmental Protection Agency (EPA), an EDC is an exogenous compound that may interfere with synthesis, secretion, transport, metabolism, receptor binding or elimination of endogenous hormones, altering the endocrine and homeostatic systems. Most EDCs appear to be highly lipophilic, therefore accumulating in the adipose tissue. The potential health issues of EDCs are not fully understood yet due to there being relatively scarce research on their exposure and associated risks via drinking water consumption. For the first time, the new Directive will protect consumers against EDCs in drinking water. Parliament was able to push through a limit value for three representative EDC compounds: Bisphenol A, Nonylphenol and Beta-estradiol. The following three benchmark values were proposed by the WHO: 0.001 µg/l Beta-estradiol, 0.3 µg/l Nonylphenol, and 0.01 µg/L Bisphenol A. Even though the WHO indicated that currently there is no evidence of risks to health from drinking water, which is a minor source of exposure, and that such risks are unlikely, these parameters were included in the Directive on the basis of the precautionary principle.

Learn more about Bisphenol A extraction and analysis from drinking water or search for related analytical applications in Thermo Scientific AppsLab Library.

This blog post covers mainly the most important chemical parameters that were renewed to set the new drinking water standards in Europe. The complete proposal of the directive, as well as all minimum requirements for parametric values to assess the quality of drinking water can be found here.