Water hardness and tap water in Erlangen

Name: Water hardness and tap water in Erlangen
Creator: Trinkwassermonitor
License: https://creativecommons.org/licenses/by/4.0/

Erlangen, Bayern · Postcode 91052, 91054, 91056, 91058

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

Short answer: The tap water in Erlangen has a total hardness of 12.88 °dH, hardness range “medium” (as of 3 February 2026). All tested parameters with a legal limit (13) meet the limits set by the German Drinking Water Ordinance (TrinkwV). Source: test report by Erlanger Stadtwerke (ESTW). WaterScore: 100 out of 100 (data coverage: 4 of 7 core parameters).

Limits of the Drinking Water OrdinancemetAll tested parameters (13), at the waterworks
Water hardness12.88 °dH, mediumNo legal limit, only a range
Data coverageCore parameters: 4 of 7Score based on complete data

Verified drinking-water values

Parameter	Value	Limit (TrinkwV)	Sampling date	Source	Status
Nitrate	9 mg/L 18 % of the limit	50 mg/L	3 February 2026	Laboratorium der Erlanger Stadtwerke AG	verified
Nitrite	< 0.02 mg/L	0.5 mg/L	3 February 2026	Laboratorium der Erlanger Stadtwerke AG	verified
Arsenic	0.002 mg/L 20 % of the limit	0.01 mg/L new plants from 2028, all from 2036: 0.004 mg/L	3 February 2026	Laboratorium der Erlanger Stadtwerke AG	verified
Uranium	0.004 mg/L 40 % of the limit	0.01 mg/L	3 February 2026	Laboratorium der Erlanger Stadtwerke AG	verified
Chloride	41 mg/L 16 % of the limit	250 mg/L	3 February 2026	Laboratorium der Erlanger Stadtwerke AG	verified
Sulphate	46 mg/L 18 % of the limit	250 mg/L	3 February 2026	Laboratorium der Erlanger Stadtwerke AG	verified
Sodium	29 mg/L 14 % of the limit	200 mg/L	3 February 2026	Laboratorium der Erlanger Stadtwerke AG	verified
Calcium	58 mg/L	–	3 February 2026	Laboratorium der Erlanger Stadtwerke AG	verified
Magnesium	20.8 mg/L	–	3 February 2026	Laboratorium der Erlanger Stadtwerke AG	verified
pH	7.68	6.5–9.5	3 February 2026	Laboratorium der Erlanger Stadtwerke AG	verified
Total hardness	12.88 °dH (medium)	no legal limit	3 February 2026	Laboratorium der Erlanger Stadtwerke AG	verified
Electrical conductivity	572 µS/cm	–	3 February 2026	Laboratorium der Erlanger Stadtwerke AG	verified
Fluoride	< 0.2 mg/L	1.5 mg/L	3 February 2026	Laboratorium der Erlanger Stadtwerke AG	verified
Iron	0.01 mg/L	0.2 mg/L	3 February 2026	Laboratorium der Erlanger Stadtwerke AG	verified
Manganese	< 0.01 mg/L	0.05 mg/L	3 February 2026	Laboratorium der Erlanger Stadtwerke AG	verified
Ammonium	< 0.04 mg/L	0.5 mg/L	3 February 2026	Laboratorium der Erlanger Stadtwerke AG	verified
Coliform bacteria	0 KBE/100ml	0 per 100 ml	3 February 2026	Laboratorium der Erlanger Stadtwerke AG	verified
Trihalomethanes (THM)	2.3 µg/L	50 µg/L	3 February 2026	Laboratorium der Erlanger Stadtwerke AG	verified

Note from the test report (in the German original): Die Tabelle zeigt Durchschnitts-/Medianwerte 2025 für sechs unterschiedliche Netzpunkte: Wasserwerk West 1, Wasserwerk Ost, Behälter am Burgberg (WT), Hochbehälter am Meilwald sowie Bezugswasser von N-ERGIE und WfW. Hier eingetragen sind die Werte von Wasserwerk West 1 (größtes eigenes Werk der ESTW); die übrigen Punkte weichen ab, z. B. Gesamthärte 9,78 °dH (Wasserwerk Ost, Härtebereich mittel) bis 15,28 °dH (Bezug N-ERGIE, Härtebereich hart), Leitfähigkeit 413–572 µS/cm, Nitrat 2–14 mg/l. Je nach Stadtteil kann daher ein Mischwasser aus mehreren dieser Quellen ankommen. Berichtsstand: 03.02.2026, Datenbasis Durchschnittswerte 2025. Blei, Kupfer, Quecksilber sowie PFAS/PFOA/PFOS/PFHxS/PFBS sind in diesem Analysenblatt nicht mit Zahlenwerten aufgeführt; laut ESTW liegen alle nicht aufgeführten TrinkwV-Parameter weit unterhalb der Grenzwerte, ein konkreter Messwert wird dafür aber nicht publiziert, daher hier bewusst weggelassen statt geschätzt.

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

Water at your own tap: The values describe the water the supplier delivers – not automatically the water at your tap. The water supplier is responsible up to the service connection (Hausanschluss); the building owner is responsible for the pipes beyond it. Lead can dissolve from lead pipes, leaded solder joints or old brass fittings, especially when water has stood in the pipes for a long time (stagnant water); this mainly affects buildings constructed before about 1973. If water has stood in the pipes for several hours, let it run until it comes out cool. If you suspect lead pipes, a lead analysis of the stagnant water by an accredited laboratory will help.

Background on household plumbing, not a measurement: in Erlangen, 46 % of buildings with living space were built before 1970, and a further 16 % 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 Erlangen

Nitrate 9 mg/L – about 18 % of the limit of 50 mg/L and in the unremarkable range. Boiling does not reduce nitrate.
Uranium 4 µg/L – within the checked range against a limit of 10 µg/L. In some regions uranium occurs naturally from the rock (geogenic).
pH 7.68 – 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 Erlangen in everyday life

At 12.88 °dH, Erlangen 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 Erlangen 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 Erlangen 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)

Values at the waterworks next to the maximum levels for bottled water “suitable for infant food”
Substance	Maximum level	Value in Erlangen
Sodium	20 mg/l	29 mg/l – above
Nitrate	10 mg/l	9 mg/l – not above
Nitrite	0.02 mg/l	below the detection limit (0.02 mg/l) – not above
Sulphate	240 mg/l	46 mg/l – not above
Fluoride	0.7 mg/l	below the detection limit (0.2 mg/l) – not above
Manganese	0.05 mg/l	below the detection limit (0.01 mg/l) – not above
Arsenic	0.005 mg/l	0.002 mg/l – not above
Uranium	0.002 mg/l	0.004 mg/l – above

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 Erlangen

Can you drink the tap water in Erlangen?

According to the verified values, yes: All tested parameters with a legal limit (13) meet the limits set by the German Drinking Water Ordinance (TrinkwV). WaterScore: 100 out of 100 (data coverage: 4 of 7 core parameters). This applies to the water from the waterworks – restrictions can only arise from old household plumbing.

How hard is the water in Erlangen?

The total hardness is 12.88 °dH – hardness range “medium”. Dose detergent for the hardness range “medium”.

Is there PFAS in the tap water in Erlangen?

The published analysis by Erlanger Stadtwerke (ESTW) that we evaluated gives no PFAS value. This does not mean there is no PFAS in the water; there is simply no figure for it. Since 12 January 2026, a limit of 0.1 µg/l has applied to the sum of PFAS-20. The supplier can tell you whether PFAS was measured and with what result.

Do I need to filter my tap water in Erlangen?

Based on the verified supplier values, a filter is not necessary. It can make sense if you do not like the taste. If you suspect lead pipes in an old building, a filter does not help; a laboratory analysis at the tap does – that is a question of the household plumbing, not of the water leaving the works.

WaterScore

Total100 / 100
Chemical safety100 / 100
Heavy metals100 / 100
Nutrients100 / 100
General parameters100 / 100
Data timeliness100 / 100
Data quality100 / 100

Data coverage: 4 of 7 core parameters. Not in the test report: Lead, Copper and PFAS (sum). Missing parameters are neither estimated nor counted as harmless: the score is based only on the values available. 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

Analysen des Erlanger Trinkwassers (Analysenblatt ESTW-2025-001) (Laboratorium der Erlanger Stadtwerke AG) · SHA-256 of the evaluated file: 29d0d618a8bc1db7…, checked on 3 October 2026

Suggested citation: Trinkwassermonitor (2026): Tap water in Erlangen. Values according to the water supplier’s test report, sampling date 3 February 2026; at the waterworks, not household plumbing. https://trinkwassermonitor.ink/en/tap-water/erlangen/

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

Data as of: 3 February 2026 · verified: 18 of 18 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 Erlangen. Retrieved from https://trinkwassermonitor.ink/en/tap-water/erlangen/.”