Drinking water in Troisdorf
2 supply zones — values can differ depending on the district. Below is the zone with the most documented parameters, the others collapsed underneath. To determine the exact match, look up the postcode.
How to read the share of the parametric value
12 % Share of the parametric value. The proportion of the permitted maximum that the measured value uses — here 12 %, so just over an eighth.
< 10 % * Below the limit of quantification. The substance was not detectable. The mark shows where the detection limit lies relative to the parametric value — the actual share of the parametric value is below that.
Several samples per year: for chemical parameters the mean value is given, for microbiological ones the highest measured value. There the parametric value is zero — a single finding would disappear in the average, and it is precisely that finding which is the information. Which reference applies is stated in the last column of the table.
bonn gesamt
SWB Energie und Wasser (Stadtwerke Bonn); Wasserlieferant: Wahnbachtalsperrenverband (WTV)| Parameter | Value | Parametric value | Share of the parametric value | Reference |
|---|---|---|---|---|
| Nitrate | 19 mg/l | 50 mg/l | 38 % | Maximum · Source [1] |
| Sodium | 17,8 mg/l | 200 mg/l | 9 % | Maximum · Source [1] |
Show all recorded parameters (7 — most recent value per parameter)
Chemical parameters (2)
| Parameter | Value | Parametric value | Share of the parametric value | Reference |
|---|---|---|---|---|
| Nitrate | 19 mg/l | 50 mg/l | 38 % | Maximum · Source [1] |
| Uranium | < 0,0001 mg/l below limit of quantification | 10 µg/l | < 1 % * | Single value · Source [1] |
* Value below the limit of quantification: the actual share of the parametric value is not known; it lies somewhere below the stated upper bound. The marker shows where the limit of quantification of the measurement lies relative to the parametric value.
Indicator parameters (2)
| Parameter | Value | Parametric value | Share of the parametric value | Reference |
|---|---|---|---|---|
| Chloride | 30 mg/l | 250 mg/l | 12 % | Maximum · Source [1] |
| Sodium | 17,8 mg/l | 200 mg/l | 9 % | Maximum · Source [1] |
Further parameters (3)
| Parameter | Value | Parametric value | Share of the parametric value | Reference |
|---|---|---|---|---|
| Calcium | 37,9 mg/l | — | — | Maximum · Source [1] |
| Magnesium | 7,5 mg/l | — | — | Maximum · Source [1] |
| Total hardness | 4,4 – 7,0 °dH | — | — | Mean · Source [2] |
Values taken unchanged from the publications linked below — for each parameter the most recent recorded value. „—" in the parametric value column: no currently valid legal parametric value is stored in our database for this parameter; the parameter register with all parametric values is being expanded continuously.
Sources: [1] bonn-37fac000.html · 2025 · retrieved on 25/07/2026 [2] https://www.stadtwerke-bonn.de/fuer-zuhause/produkte/wasser/wasseranalyse/ · 2025 · retrieved on 11/07/2026
Postcodes in this zone: 53842
Show 1 more supply zone
WW Eschmar, 53844 Troisdorf, Strang 1, Werksausgang
Stadtwerke Troisdorf GmbHAssigned via the water supplier — the exact supply zone boundary within the postcode is not yet linked.
These values are more than a year old. The most recent analysis the water supplier has published for this zone dates from 18/06/2025. We have no newer values — which is why we show the latest available ones rather than none at all. They say nothing about how the water has changed since then.
Water hardness
5.4 °dH
Hardness range soft
| Parameter | Value | Parametric value | Share of the parametric value | Reference |
|---|---|---|---|---|
| Nitrate | 15,8 mg/l | 50 mg/l | 32 % | Single value |
| Lead | <0,0005 mg/l below limit of quantification | 10 µg/l | < 5 % * | Single value |
| Escherichia coli (E. coli) | 0 KBE/100ml | 0/100 ml | — | Single value |
| Sulphate | 20,6 mg/l | 250 mg/l | 8 % | Single value |
| Sodium | 17,0 mg/l | 200 mg/l | 9 % | Single value |
* Value below the limit of quantification: the actual share of the parametric value is not known; it lies somewhere below the stated upper bound. The marker shows where the limit of quantification of the measurement lies relative to the parametric value.
Show all recorded parameters (112 — most recent value per parameter)
Microbiology (2)
| Parameter | Value | Parametric value | Share of the parametric value | Reference |
|---|---|---|---|---|
| Escherichia coli (E. coli) | 0 KBE/100ml | 0/100 ml | — | Single value |
| Intestinal enterococci | 0 KBE/100ml | 0/100 ml | — | Single value |
Chemical parameters (81)
| Parameter | Value | Parametric value | Share of the parametric value | Reference |
|---|---|---|---|---|
| 1,1,1-Trichloroethane | <0,05 µg/l below limit of quantification | — | — | Single value |
| 1,2-dichloroethane | <0,20 µg/l below limit of quantification | 3 µg/l | < 7 % * | Single value |
| 1,2-Dichloropropane | <0,20 µg/l below limit of quantification | — | — | Single value |
| 2,4-D | <0,03 µg/l below limit of quantification | — | — | Single value |
| Aldrin | <0,03 µg/l below limit of quantification | 30 ng/l | < 100 % * | Single value |
| Antimony | <0,00050 mg/l below limit of quantification | 5 µg/l | < 10 % * | Single value |
| Arsenic | <0,0005 mg/l below limit of quantification | 10 µg/l | < 5 % * | Single value |
| Atrazine | <0,03 µg/l below limit of quantification | — | — | Single value |
| Azoxystrobin | <0,03 µg/l below limit of quantification | — | — | Single value |
| Bentazone | <0,03 µg/l below limit of quantification | — | — | Single value |
| Benzene | <0,20 µg/l below limit of quantification | 1 µg/l | < 20 % * | Single value |
| Benzo(ghi)perylene | <0,01 µg/l below limit of quantification | — | — | Single value |
| Bisphenol A | <0,03 µg/l below limit of quantification | 2.5 µg/l | < 1 % * | Single value |
| Boron | 0,04 mg/l | 1 mg/l | 4 % | Single value |
| Boscalid | <0,03 µg/l below limit of quantification | — | — | Single value |
| Bromacil | <0,05 µg/l below limit of quantification | — | — | Single value |
| Bromate | <3,0 µg/l below limit of quantification | 10 µg/l | < 30 % * | Single value |
| Bromodichloromethane | <0,05 µg/l below limit of quantification | — | — | Single value |
| Bromoxynil | <0,03 µg/l below limit of quantification | — | — | Single value |
| Cadmium | <0,00010 mg/l below limit of quantification | 3 µg/l | < 3 % * | Single value |
| Carbofuran | <0,05 µg/l below limit of quantification | — | — | Single value |
| Chloridazon | <0,03 µg/l below limit of quantification | — | — | Single value |
| Chlorotoluron | <0,03 µg/l below limit of quantification | — | — | Single value |
| Chromium | <0,0005 mg/l below limit of quantification | 25 µg/l | < 2 % * | Single value |
| Copper | <0,02 mg/l below limit of quantification | 2 mg/l | < 1 % * | Single value |
| Cyanide | <0,015 mg/l below limit of quantification | 50 µg/l | < 30 % * | Single value |
| Desethylatrazine | <0,03 µg/l below limit of quantification | — | — | Single value |
| Desisopropylatrazine | <0,03 µg/l below limit of quantification | — | — | Single value |
| Dibromochloromethane | <0,05 µg/l below limit of quantification | — | — | Single value |
| Dicamba | <0,03 µg/l below limit of quantification | — | — | Single value |
| Dichloromethane | <0,20 µg/l below limit of quantification | — | — | Single value |
| Dichlorprop | <0,03 µg/l below limit of quantification | — | — | Single value |
| Dieldrin | <0,03 µg/l below limit of quantification | 30 ng/l | < 100 % * | Single value |
| Diflufenican | <0,03 µg/l below limit of quantification | — | — | Single value |
| Dimethachlor | <0,03 µg/l below limit of quantification | — | — | Single value |
| Dimethenamid | <0,03 µg/l below limit of quantification | — | — | Single value |
| Diuron | <0,03 µg/l below limit of quantification | — | — | Single value |
| Ethofumesate | <0,03 µg/l below limit of quantification | — | — | Single value |
| Flufenacet | <0,03 µg/l below limit of quantification | — | — | Single value |
| Fluoranthene | <0,01 µg/l below limit of quantification | — | — | Single value |
| Fluoride | 0,05 mg/l | 1.5 mg/l | 3 % | Single value |
| Heptachlor | <0,03 µg/l below limit of quantification | 30 ng/l | < 100 % * | Single value |
| Heptachlor epoxide | <0,03 µg/l below limit of quantification | 30 ng/l | < 100 % * | Single value |
| Hexazinone | <0,03 µg/l below limit of quantification | — | — | Single value |
| Imidacloprid | <0,03 µg/l below limit of quantification | — | — | Single value |
| Indeno(1,2,3-cd)pyrene | <0,01 µg/l below limit of quantification | — | — | Single value |
| Isoproturon | <0,03 µg/l below limit of quantification | — | — | Single value |
| Lead | <0,0005 mg/l below limit of quantification | 10 µg/l | < 5 % * | Single value |
| Lenacil | <0,05 µg/l below limit of quantification | — | — | Single value |
| MCPA | <0,03 µg/l below limit of quantification | — | — | Single value |
| Mecoprop | <0,03 µg/l below limit of quantification | — | — | Single value |
| Mercury | <0,00010 mg/l below limit of quantification | 1 µg/l | < 10 % * | Single value |
| Metazachlor | <0,03 µg/l below limit of quantification | — | — | Single value |
| Metobromuron | <0,03 µg/l below limit of quantification | — | — | Single value |
| Metolachlor | <0,03 µg/l below limit of quantification | — | — | Single value |
| Metoxuron | <0,03 µg/l below limit of quantification | — | — | Single value |
| Metribuzin | <0,03 µg/l below limit of quantification | — | — | Single value |
| Monuron | <0,03 µg/l below limit of quantification | — | — | Single value |
| Nickel | <0,0010 mg/l below limit of quantification | 20 µg/l | < 5 % * | Single value |
| Nitrate | 15,8 mg/l | 50 mg/l | 32 % | Single value |
| Nitrite | <0,01 mg/l below limit of quantification | 0.5 mg/l | < 2 % * | Single value |
| Pendimethalin | <0,03 µg/l below limit of quantification | — | — | Single value |
| Prometryn | <0,03 µg/l below limit of quantification | — | — | Single value |
| Propazine | <0,03 µg/l below limit of quantification | — | — | Single value |
| Propiconazole | <0,03 µg/l below limit of quantification | — | — | Single value |
| Prosulfocarb | <0,03 µg/l below limit of quantification | — | — | Single value |
| Sebuthylazine | <0,03 µg/l below limit of quantification | — | — | Single value |
| Selenium | <0,0005 mg/l below limit of quantification | 10 µg/l | < 5 % * | Single value |
| Simazine | <0,03 µg/l below limit of quantification | — | — | Single value |
| Tebuconazole | <0,03 µg/l below limit of quantification | — | — | Single value |
| Terbuthylazine | <0,03 µg/l below limit of quantification | — | — | Single value |
| Terbutryn | <0,03 µg/l below limit of quantification | — | — | Single value |
| Tetrachloroethene | <0,05 µg/l below limit of quantification | — | — | Single value |
| Tetrachloromethane | <0,05 µg/l below limit of quantification | — | — | Single value |
| Tri-allate | <0,03 µg/l below limit of quantification | — | — | Single value |
| Triadimenol | <0,03 µg/l below limit of quantification | — | — | Single value |
| Tribromomethane (bromoform) | <0,05 µg/l below limit of quantification | — | — | Single value |
| Trichloroethene | <0,05 µg/l below limit of quantification | — | — | Single value |
| Trichloromethane (chloroform) | <0,05 µg/l below limit of quantification | — | — | Single value |
| Trihalomethanes — Total | 0,00 µg/l | 50 µg/l | 0 % | Single value |
| Uranium | <0,00010 mg/l below limit of quantification | 10 µg/l | < 1 % * | Single value |
* Value below the limit of quantification: the actual share of the parametric value is not known; it lies somewhere below the stated upper bound. The marker shows where the limit of quantification of the measurement lies relative to the parametric value.
Indicator parameters (17)
| Parameter | Value | Parametric value | Share of the parametric value | Reference |
|---|---|---|---|---|
| Aluminium | <0,04 mg/l below limit of quantification | 0.2 mg/l | < 20 % * | Single value |
| Ammonium | <0,05 mg/l below limit of quantification | 0.5 mg/l | < 10 % * | Single value |
| Calcite dissolution capacity | 2,68 mg/l | 5 mg/l CaCO3 | — | Single value |
| Chloride | 21,0 mg/l | 250 mg/l | 8 % | Single value |
| Clostridium perfringens (including spores) | 0 KBE/100ml | 0/100 ml | — | Single value |
| Coliform bacteria | 0 KBE/100ml | 0/100 ml | — | Single value |
| Colour | <0,10 m -1 below limit of quantification | 0.5 m⁻¹ | — | Single value |
| Conductivity (25 °C) | 294 µS/cm | 2,790 µS/cm | — | Single value |
| Iron | <0,02 mg/l below limit of quantification | 0.2 mg/l | < 10 % * | Single value |
| Manganese | <0,001 mg/l below limit of quantification | 50 µg/l | < 2 % * | Single value |
| Odour | 1 TON | für den Verbraucher annehmbar | — | Single value |
| pH | 7,85 | 6,5–9,5 | — | Single value |
| Sodium | 17,0 mg/l | 200 mg/l | 9 % | Single value |
| Sulphate | 20,6 mg/l | 250 mg/l | 8 % | Single value |
| Taste | ohne | für den Verbraucher annehmbar | — | Single value |
| Total organic carbon (TOC) | 0,41 mg/l | ohne anormale Veränderung | — | Single value |
| Turbidity | 0,07 NTU | 1 NTU | — | Single value |
* Value below the limit of quantification: the actual share of the parametric value is not known; it lies somewhere below the stated upper bound. The marker shows where the limit of quantification of the measurement lies relative to the parametric value.
Further parameters (12)
| Parameter | Value | Parametric value | Share of the parametric value | Reference |
|---|---|---|---|---|
| Acid capacity to pH 4.3 | 1,47 mmol/l | — | — | Single value |
| Base capacity to pH 8.2 | 0,04 mmol/l | — | — | Single value |
| Calcium | 28,4 mg/l | — | — | Single value |
| Carbonate hardness | 4,1 °KH | — | — | Single value |
| Hydrogen carbonate | 89,9 mg/l | — | — | Single value |
| Magnesium | 6,4 mg/l | — | — | Single value |
| Oxygen | 11,0 mg/l | — | — | Single value |
| Phosphate | <0,05 mg/l below limit of quantification | — | — | Single value |
| Potassium | 2,5 mg/l | — | — | Single value |
| Saturation index | -0,290 | — | — | Single value |
| Strontium | 0,10 mg/l | — | — | Single value |
| Total hardness | 0,97 mol/m3 | — | — | Single value |
Values taken unchanged from the publications linked below — for each parameter the most recent recorded value. „—" in the parametric value column: no currently valid legal parametric value is stored in our database for this parameter; the parameter register with all parametric values is being expanded continuously.
Source: https://www.stadtwerke-troisdorf.de/fileadmin/user_upload/5.0_Service/Download-center/Wasser/20250620_28_WW_Eschmar_53844_Troisdorf.pdf · Köln, den 20.06.2025 · 13.05.2025 bis 18.06.2025 · retrieved on 11/07/2026
Frequently asked questions about drinking water in Troisdorf
- How much nitrate is in the drinking water in Troisdorf?
- SWB Energie und Wasser (Stadtwerke Bonn); Wasserlieferant: Wahnbachtalsperrenverband (WTV) publishes a nitrate value of 19 mg/l for the supply zone bonn gesamt. The statutory parametric value is 50 mg/l; the measured value represents 38 % of the parametric value. Basis: Publication by the water supplier, retrieved on 25/07/2026.
- Who supplies the drinking water in Troisdorf?
- SWB Energie und Wasser (Stadtwerke Bonn); Wasserlieferant: Wahnbachtalsperrenverband (WTV). The values shown here come from the supply zone bonn gesamt and apply to the water the supplier delivers. What happens between the building connection and the tap — in old lead pipes, for example — is not covered by these analyses; information on that is provided by owners, the health authority or an examination by an accredited laboratory.
General questions — how current the data is, limit of quantification, parametric values, who is behind this site — are answered under Questions & answers.