Water hardness and tap water in Erfurt

Erfurt, Thüringen · Postcode 99084, 99085, 99086, 99089, 99096, 99097

This page is a translation of the German version; the German page is authoritative. German version · Report a translation error

• Limits of the Drinking Water OrdinancemetAll tested parameters (8), at the waterworks
• Water hardness12.8 °dH, mediumNo legal limit, only a range
• Data coverageCore parameters: 2 of 7Score provisional

Verified drinking-water values

Note from the test report (in the German original): ThüWa versorgt Erfurt aus 'Mischwasser' (Grund- + Talsperrenwasser, ca. 172.000 Einwohner, echte Mehrheit) und 'Fernwasser' (reines Talsperrenwasser aus der Ohratalsperre, ca. 75.000 Einwohner) - Fernwasser ist deutlich weicher (3,2 statt ca. 12,5 °dH) und wird hier nicht eingerechnet. Mischwasser ist im Adress-Lookup-Tool des Versorgers weiter in vier fast identische Unterzonen (S/A/N/M) aufgeteilt; 'Mischwasser_S' (die meisten Adresseinträge) wird hier als Primärwert geführt, die anderen Unterzonen weichen nur minimal ab (Härte 12,2-12,8 °dH). Kein gedrucktes Analysedatum vorhanden - die Werte sind laut Versorger ein jährlich aktualisierter Mittelwert; als Datum wird das Abrufdatum der Live-Quelle (23.09.2026) verwendet, offen als Abrufdatum gekennzeichnet, nicht als Probenahmedatum. Nitrit, Ammonium, Fluorid, Blei, Arsen, Kupfer, Quecksilber, Trihalogenmethane und Mikrobiologie sind nicht veröffentlicht. PFAS: ThüWa testet freiwillig auf 20 PFAS-Verbindungen und erklärt (Stand November 2025), keine davon liege über der Bestimmungsgrenze - das ist nur eine qualitative Aussage ohne Zahlenwert und wird daher nicht als Messwert eingetragen, sondern nur hier im Caveat erwähnt.

Is a value wrong or out of date? Report an error – we check every report against the original source.

Background on household plumbing, not a measurement: in Erfurt, 51 % of buildings with living space were built before 1970, and a further 6 % between 1970 and 1979 (Zensus 2022, Statistisches Bundesamt, dl-de/by-2-0). (Zensus 2022) According to the German Environment Agency (Umweltbundesamt), lead pipes exist at most in houses built before 1973 – and by no means in all of them. Whether there are any in your house is known to the owner or a plumber. (UBA)

What the values mean for Erfurt

• Nitrate 11.6 mg/L – about 23 % of the limit of 50 mg/L and in the medium range – such values occur in catchments shaped by agriculture. Boiling does not reduce nitrate.
• Uranium 0.5 µg/L – unremarkable against a limit of 10 µg/L. In some regions uranium occurs naturally from the rock (geogenic).
• pH 7.9 – within the range of the Drinking Water Ordinance (6.5 to 9.5). The pH determines how corrosive the water is in household plumbing.

Water hardness in Erfurt in everyday life

At 12.8 °dH, Erfurt is in the hardness range “medium” (soft: below 8.4 °dH, medium: 8.4–14 °dH, hard: above 14 °dH).

• Dose detergent for the hardness range “medium”.
• As a rule of thumb, descale the kettle about every four to six weeks and the coffee machine as the manufacturer recommends.
• A limescale protection device is not a must at medium hardness; regular descaling is often enough.

Baby food and low sodium: tap water in Erfurt next to the bottled-water thresholds

Bottled water may only be labelled “suitable for preparing infant food” („geeignet für die Zubereitung von Säuglingsnahrung“) if it keeps to the maximum levels of the German Mineral and Table Water Ordinance (Mineral- und Tafelwasser-Verordnung, Annex 6). Here the published values for Erfurt are shown next to them, each substance on its own. This is a comparison with labelling thresholds for bottled water, not a statement on whether your tap water is suitable for baby food. (Min/TafelWV, Anlage 6)

Against the other thresholds of Annex 6, the water would qualify as: low in sodium (“suitable for a low-sodium diet”) (Sodium 15.6 mg/l, threshold below 20 mg/l).

For context: the German Environment Agency (Umweltbundesamt) considers preparing baby food with bottled water carrying this label necessary only in rare cases, for example when tap water is temporarily allowed to contain more than 50 mg/l nitrate. (UBA 2016, p. 59) Water from lead pipes in the house is always unsuitable for infants. (UBA 2020, p. 16) The values apply at the waterworks. Questions about baby food are answered by your midwife, your paediatrician and the health office (Gesundheitsamt).

Frequently asked questions about tap water in Erfurt

WaterScore

• Total (provisional)100 / 100
• Chemical safety100 / 100
• Heavy metals100 / 100
• Nutrients100 / 100
• General parameters100 / 100
• Data timeliness100 / 100
• Data quality100 / 100

Data coverage: 2 of 7 core parameters. Not in the test report: Nitrite, Lead, Copper, Arsenic and PFAS (sum). Missing parameters are neither estimated nor counted as harmless: the score is based only on the values available and is therefore provisional. It is not a health assessment and says nothing about the water beyond the service connection. Methodology v3: how we calculate the WaterScore.

Evidence: cite and check

• Herkunft und Qualität - Wasserhärte und Trinkwasserqualität (Zone Mischwasser_S) (ThüWa ThüringenWasser GmbH (Stadtwerke Erfurt Gruppe))

Suggested citation: Trinkwassermonitor (2026): Tap water in Erfurt. Values according to the water supplier’s test report, sampling date 23 September 2026; at the waterworks, not household plumbing. https://trinkwassermonitor.ink/en/tap-water/erfurt/

JSON: /api/v1/evidence?city=erfurt

Data as of: 23 September 2026 · verified: 12 of 12 evaluated parameters.

This page shows only verified test data with sources, or states explicitly where data is missing (no estimated values). Cite as: “Trinkwassermonitor (2026). Tap water in Erfurt. Retrieved from https://trinkwassermonitor.ink/en/tap-water/erfurt/.”

Further information

• German version: Trinkwasser in Erfurt
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