TrinkwassermonitorTap water in Germany

Water hardness and tap water in Ober-Olm

Landkreis Mainz-Bingen, Rheinland-Pfalz · Postcode 55270

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 Ober-Olm has a total hardness of 18.5 °dH, hardness range “hard” (as of 2 March 2026). All tested parameters with a legal limit (19) meet the limits set by the German Drinking Water Ordinance (TrinkwV). Source: test report by Wasserversorgung Rheinhessen-Pfalz (WVR). WaterScore: 100 out of 100 (data coverage: 7 of 7 core parameters).

Verified drinking-water values

ParameterValueLimit (TrinkwV)Sampling dateSourceStatus
Nitrate2.1 mg/L50 mg/L2 March 2026Wasserversorgung Rheinhessen-Pfalz GmbHverified
Nitrite< 0.02 mg/L0.5 mg/L2 March 2026Wasserversorgung Rheinhessen-Pfalz GmbHverified
PFAS (sum)0.012 µg/L
0.1 µg/L

2 March 2026Wasserversorgung Rheinhessen-Pfalz GmbHverified
PFOA0.001 µg/L–2 March 2026Wasserversorgung Rheinhessen-Pfalz GmbHverified
PFOS0.002 µg/L–2 March 2026Wasserversorgung Rheinhessen-Pfalz GmbHverified
PFHxS0.001 µg/L–2 March 2026Wasserversorgung Rheinhessen-Pfalz GmbHverified
PFBS0.004 µg/L–2 March 2026Wasserversorgung Rheinhessen-Pfalz GmbHverified
TFA (Trifluoressigsäure)0.8 µg/L–2 March 2026Wasserversorgung Rheinhessen-Pfalz GmbHverified
PFNA< 0.001 µg/L–2 March 2026Wasserversorgung Rheinhessen-Pfalz GmbHverified
Lead< 0.001 mg/L0.01 mg/L
2 March 2026Wasserversorgung Rheinhessen-Pfalz GmbHverified
Arsenic< 0.001 mg/L0.01 mg/L
2 March 2026Wasserversorgung Rheinhessen-Pfalz GmbHverified
Uranium< 0.0005 mg/L0.01 mg/L2 March 2026Wasserversorgung Rheinhessen-Pfalz GmbHverified
Mercury< 0.00005 mg/L0.001 mg/L2 March 2026Wasserversorgung Rheinhessen-Pfalz GmbHverified
Copper< 0.005 mg/L2 mg/L2 March 2026Wasserversorgung Rheinhessen-Pfalz GmbHverified
Cadmium< 0.0005 mg/L0.003 mg/L2 March 2026Wasserversorgung Rheinhessen-Pfalz GmbHverified
Chromium< 0.0005 mg/L0.025 mg/L
2 March 2026Wasserversorgung Rheinhessen-Pfalz GmbHverified
Nickel< 0.002 mg/L0.02 mg/L2 March 2026Wasserversorgung Rheinhessen-Pfalz GmbHverified
Chloride52.5 mg/L
250 mg/L2 March 2026Wasserversorgung Rheinhessen-Pfalz GmbHverified
Sulphate84 mg/L
250 mg/L2 March 2026Wasserversorgung Rheinhessen-Pfalz GmbHverified
Sodium35.3 mg/L
200 mg/L2 March 2026Wasserversorgung Rheinhessen-Pfalz GmbHverified
Calcium105 mg/L–2 March 2026Wasserversorgung Rheinhessen-Pfalz GmbHverified
Magnesium16.7 mg/L–2 March 2026Wasserversorgung Rheinhessen-Pfalz GmbHverified
pH7.246.5–9.52 March 2026Wasserversorgung Rheinhessen-Pfalz GmbHverified
Total hardness18.5 °dH (hard)no legal limit2 March 2026Wasserversorgung Rheinhessen-Pfalz GmbHverified
Electrical conductivity783 µS/cm–2 March 2026Wasserversorgung Rheinhessen-Pfalz GmbHverified
Fluoride0.2 mg/L
1.5 mg/L2 March 2026Wasserversorgung Rheinhessen-Pfalz GmbHverified
Iron< 0.01 mg/L0.2 mg/L2 March 2026Wasserversorgung Rheinhessen-Pfalz GmbHverified
Manganese< 0.005 mg/L0.05 mg/L2 March 2026Wasserversorgung Rheinhessen-Pfalz GmbHverified
Ammonium< 0.04 mg/L0.5 mg/L2 March 2026Wasserversorgung Rheinhessen-Pfalz GmbHverified
Coliform bacteria0 KBE/100ml0 per 100 ml2 March 2026Wasserversorgung Rheinhessen-Pfalz GmbHverified
Säurekapazität bis pH 4,35.33 mmol/L–2 March 2026Wasserversorgung Rheinhessen-Pfalz GmbHverified

Note from the test report (in the German original): Wasserversorgung Rheinhessen-Pfalz GmbH · Prüfbericht Nr. 7974550 (freigegeben 30.04.2026), Versorgungsgebiet HB OberOlm. Auf ihrer Karte der Wasseranalysen ordnet die WVR Ober-Olm diesem Bericht zu. Die Probe stammt vom 02.03.2026 aus dem Ortsnetz in Klein-Winternheim (Hahn Druckmindereranlage, Ortseingang), nicht aus Ober-Olm selbst und nicht ab Wasserwerk; die Hausinstallation ist nicht erfasst. Es ist eine Einzelprobe. Trihalogenmethane bildet der Bericht nicht als Summe, deshalb fehlt dieser Wert hier.

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 Ober-Olm, 32 % of buildings with living space were built before 1970, and a further 24 % 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 Ober-Olm

Water hardness in Ober-Olm in everyday life

At 18.5 °dH, Ober-Olm is in the hardness range “hard” (soft: below 8.4 °dH, medium: 8.4–14 °dH, hard: above 14 °dH).

Baby food and low sodium: tap water in Ober-Olm 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 Ober-Olm 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)

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.

Values at the waterworks next to the maximum levels for bottled water “suitable for infant food”
SubstanceMaximum levelValue in Ober-Olm
Sodium20 mg/l35.3 mg/l – above the bottled-water threshold
Nitrate10 mg/l2.1 mg/l – not above
Nitrite0.02 mg/lbelow the detection limit (0.02 mg/l) – not above
Sulphate240 mg/l84 mg/l – not above
Fluoride0.7 mg/l0.2 mg/l – not above
Manganese0.05 mg/lbelow the detection limit (0.005 mg/l) – not above
Arsenic0.005 mg/lbelow the detection limit (0.001 mg/l) – not above
Uranium0.002 mg/lbelow the detection limit (0.0005 mg/l) – not above

Questions about baby food are answered by your midwife, your paediatrician and the health office (Gesundheitsamt).

Frequently asked questions about tap water in Ober-Olm

Can you drink the tap water in Ober-Olm?

According to the verified values, yes: All tested parameters with a legal limit (19) meet the limits set by the German Drinking Water Ordinance (TrinkwV). WaterScore: 100 out of 100 (data coverage: 7 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 Ober-Olm?

The total hardness is 18.5 °dH – hardness range “hard”. Dose detergent for the hardness range “hard” – a larger amount is needed; a water softener for the washing machine can save detergent.

Is there PFAS in the tap water in Ober-Olm?

Yes, in measurable amounts: according to the published analysis by Wasserversorgung Rheinhessen-Pfalz (WVR) (as of 2 March 2026), the sum of PFAS-20 is 0.012 µg/l – that is 12 % of the limit of 0.1 µg/l, which has applied since 12 January 2026. Even this sum of all 20 substances is below the limit of 0.02 µg/l that applies from 12 January 2028 to the sum of four of them (PFAS-4).

Do I need to filter my tap water in Ober-Olm?

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

Data coverage: 7 of 7 core parameters. 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 v4: how we calculate the WaterScore.

Evidence: cite and check

Suggested citation: Trinkwassermonitor (2026): Tap water in Ober-Olm. Values according to the water supplier’s test report, sampling date 2 March 2026; at the waterworks, not household plumbing. https://trinkwassermonitor.ink/en/tap-water/ober-olm/

JSON: /api/v1/evidence?city=ober-olm

Data as of: 2 March 2026 · verified: 31 of 31 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 Ober-Olm. Retrieved from https://trinkwassermonitor.ink/en/tap-water/ober-olm/.”

Further information