Drinking Water Quality Index Germany — A Classification

Germany has overall very good to excellent drinking water. That is the most important message upfront. According to the Federal Environment Agency, over 99 percent of samples comply with the legal limit values; for large central water supply systems, the agency certifies the drinking water as good to very good quality.

The Langwater Drinking Water Quality Index confirms this picture. Even the cities at the lower end of the ranking are still clearly within the permissible range. The ranking therefore does not distinguish between “good” and “bad,” but between “very pure” and “still very good, but somewhat closer to the limit values.”

On the methodology of the index

The Langwater Drinking Water Quality Index is calculated as the average utilisation of limit values across five main parameters: lead, uranium, nitrate, nitrite, and fluoride. The lower the value, the purer the water in the context of this analysis.

PFAS-20 values are additionally shown on the map but are not factored into the score, as this data comes from a separate sample source (BUND) and is not available for all cities as a fully comparable data basis. The ranking currently includes 56 cities with complete data. Their average index value is 12.81 percent, the median 10.72 percent. This means that even the middle of the field uses the legal limit values on average only to a relatively small extent.

Where is the water particularly pure?

At the top of the ranking are Neustadt an der Weinstraße, Bremen, Wolfsburg, Speyer, and Hamburg. Their index values range between 3.17 and 6.45 percent — meaning, in simplified terms, that the monitored substances are on average only a very small fraction of the legal limit values.

Notably, the top cities include both northern German locations and cities from Rhineland-Palatinate. One explanation could be that Germany's groundwater resources are distributed very unevenly by region and depend heavily on the geological substrate and hydrogeological conditions. Particularly productive pore groundwater aquifers are found, for example, in the North German Plain, the Alpine foothills, and the Upper Rhine Graben. Such geological zones can create favourable conditions for water extraction, although actual quality always depends additionally on protection, land use, and treatment.

Which cities are at the lower end — and what does that actually mean?

At the lower end of the ranking are Koblenz, Offenbach am Main, Bamberg, Schweinfurt, and Straubing. Their index values range from 21.73 to 27.47 percent. While this sounds considerably higher compared to the top cities, it still means that even the lower-ranked cities are on average well below the permissible limit values for the monitored substances. These cities too therefore have, by the logic of the index, not poor but rather legally compliant and overall good drinking water.

Why are there differences in drinking water quality at all?

The differences can be explained to a significant extent by geology, hydrogeology, and the respective catchment area. It starts with the substrate: depending on whether water flows through sands and gravels, limestone and karst rock, sandstone, or more poorly permeable solid rock, its natural composition changes. The BGR (Federal Institute for Geosciences and Natural Resources) explicitly states that groundwater resources in Germany are distributed unevenly by region depending on the geological substrate and hydrogeological conditions.

This influences not only yield, but also residence time, mineralisation, and the natural hydrochemical signature. Human influences add to this. The Federal Environment Agency cites inputs from agriculture as an important factor; in particular, nitrogen-based fertilisation can contribute to nitrate contamination of groundwater. If a city is supplied from a catchment area with intensive agriculture, this can affect nitrate levels more strongly than in regions with different land-use patterns. The type of water resource — such as groundwater, bank filtrate, surface water, or reservoir water — is equally relevant.

Why even very good water is not optimal water

Even very good, meaning low-contaminant, water is not automatically optimal for every person. For quality in a health-practical sense, it is not only what is absent from the water that matters, but also what it contains: water can be very pure and yet deliver only few minerals such as calcium or magnesium. At the same time, the need for mineralisation is not the same for all people. Depending on diet, stage of life, activity level, and individual health situation, different compositions may be beneficial.

Minerals influence not only water quality but also, significantly, its taste. This plays a major role in adequate fluid intake, as it has been shown that people drink more when water tastes good — and good hydration is fundamental to health and longevity.

What matters, therefore, is balance: as low in contaminants as possible, while at the same time suited to the body's personal needs.

Caution: Microplastics

This is precisely where an interesting contradiction in consumer behaviour emerges: despite German tap water being of very high quality, many consumers prefer bottled water. Per-capita consumption of mineral and medicinal water in Germany rose to 128.8 litres in 2025. The reason: many Germans are not fully satisfied with the taste of their tap water, or miss the desired mineralisation, and therefore buy expensive premium mineral water in bottles.

At this point, however, a further problem arises: microplastics. Studies show that bottled water contains on average significantly more microplastics than tap water. One study found that a person drinking exclusively bottled water ingests up to 130,000 plastic particles per year, compared to only around 4,000 for tap water. Microplastics have even been detected in glass bottles, often due to abrasion from caps or the bottling process. Those who buy premium mineral water in bottles to obtain what they believe is purer, more mineral-rich water are therefore often unknowingly ingesting a considerable amount of microplastic.

This is where Langwater comes in

LANGWATER is a Swiss company that solves a dilemma every bottled water has failed at so far. The starting point is your own tap water, filtered with the most advanced method available — reverse osmosis. All residues, down to the smallest particles, are reliably removed.

What really sets LANGWATER apart is the next step: precise, individually adjustable remineralisation. Pure osmosis water tastes flat, is slightly acidic, and is not suitable for daily enjoyment — because high-quality filtration removes everything, including the essential minerals your body needs. LANGWATER's remineralisation system therefore deliberately re-adds calcium, magnesium, and potassium to the water, creating a premium drinking experience: balanced, slightly alkaline water with a pH value of around 7.8 in the default setting.

Because minerals shape the taste of water, our water sommelier developed a dedicated recipe — for a soft, pleasantly tasting water you enjoy drinking every day. Thanks to the patented dosing system of TheWell 2, the mineral intensity can be adjusted entirely to personal need and taste.

And all of this entirely without plastic bottles — and without microplastics. That way, the water you drink at home becomes truly high quality: cleaner than tap water and freer of microplastics than any product off the supermarket shelf. The best of all worlds — pure water, mineralised water, no bottle.

The ecological and economic balance is equally clear. Every litre of bottled water consumes crude oil for packaging, fuel for transport across the country, and your own effort carrying it home — only for the bottle to be thrown away minutes later. LANGWATER makes all of that unnecessary. You save thousands of bottles. And at around €0.12 per litre — compared to €0.50 or more for premium bottled water — the system pays off for most households within the first year.

LANGWATER has questioned bottled water, rethought filtration standards, and created what did not exist before: beverages without a bottle.

“The bottled water and soft drink industry is inefficient and unsustainable. I wanted to change that — for my children's generation.”
Jan-Erik Lundberg, Founder & CEO

Sources

• • Beverage industry — People in Germany drink more mineral water (Lebensmittel Praxis, 2026)
• • Consumer study: Mineral water is a firm part of drinking culture and a conscious lifestyle (VDM, 2022)
• • Study finds more microplastics in glass bottles than in plastic bottles (Apotheken Umschau, 2025)