Drinking water in Düren
5 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.
Derichsweiler (Lieferant: WZV Langerwehe)
Stadtwerke Düren (SWD)Assigned via the water supplier — the exact supply zone boundary within the postcode is not yet linked.
Water hardness
8.2 °dH
Hardness range soft
| Parameter | Value | Parametric value | Share of the parametric value | Reference |
|---|---|---|---|---|
| Nitrate | 8,4 mg/l | 50 mg/l | 17 % | Mean · Derichsweiler (Lieferant: WZV Langerwehe) |
| Sulphate | 51 mg/l | 250 mg/l | 20 % | Mean · Derichsweiler (Lieferant: WZV Langerwehe) |
| Sodium | 0,47 mmol/l | 200 mg/l | — | Mean · Derichsweiler (Lieferant: WZV Langerwehe) |
Show all recorded parameters (15 — most recent value per parameter)
Chemical parameters (1)
| Parameter | Value | Parametric value | Share of the parametric value | Reference |
|---|---|---|---|---|
| Nitrate | 8,4 mg/l | 50 mg/l | 17 % | Mean · Derichsweiler (Lieferant: WZV Langerwehe) |
Indicator parameters (4)
| Parameter | Value | Parametric value | Share of the parametric value | Reference |
|---|---|---|---|---|
| Chloride | 17 mg/l | 250 mg/l | 7 % | Mean · Derichsweiler (Lieferant: WZV Langerwehe) |
| pH | 7,90 | 6,5–9,5 | — | Mean · Derichsweiler (Lieferant: WZV Langerwehe) |
| Sodium | 0,47 mmol/l | 200 mg/l | — | Mean · Derichsweiler (Lieferant: WZV Langerwehe) |
| Sulphate | 51 mg/l | 250 mg/l | 20 % | Mean · Derichsweiler (Lieferant: WZV Langerwehe) |
Further parameters (10)
| Parameter | Value | Parametric value | Share of the parametric value | Reference |
|---|---|---|---|---|
| Acid capacity to pH 4.3 | 1,97 mmol/l | — | — | Mean · Derichsweiler (Lieferant: WZV Langerwehe) |
| Base capacity to pH 8.2 | 0,05 mmol/l | — | — | Mean · Derichsweiler (Lieferant: WZV Langerwehe) |
| Calcium | 0,95 mmol/l | — | — | Mean · Derichsweiler (Lieferant: WZV Langerwehe) |
| Carbonate hardness | 5,4 °dH | — | — | Mean · Derichsweiler (Lieferant: WZV Langerwehe) |
| Magnesium | 0,50 mmol/l | — | — | Mean · Derichsweiler (Lieferant: WZV Langerwehe) |
| Non-carbonate hardness | 2,8 °dH | — | — | Mean · Derichsweiler (Lieferant: WZV Langerwehe) |
| Oxygen | 10,2 mg/l | — | — | Mean · Derichsweiler (Lieferant: WZV Langerwehe) |
| Phosphate | 0,19 mg/l | — | — | Mean · Derichsweiler (Lieferant: WZV Langerwehe) |
| Potassium | 0,05 mmol/l | — | — | Mean · Derichsweiler (Lieferant: WZV Langerwehe) |
| Total hardness | 8,2 °dH | — | — | Mean · Derichsweiler (Lieferant: WZV Langerwehe) |
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-dueren.de/fileadmin/user_upload/2025_Haerteliste_neu.pdf · Juli 2024 bis Juni 2025 · retrieved on 11/07/2026
Postcodes in this zone: 52349 , 52351 , 52353 , 52355
Show 4 more supply zones
Wasserbehälter Hemgenberg: Berzbuir, Birgel, Kufferath
Stadtwerke Düren (SWD)Assigned via the water supplier — the exact supply zone boundary within the postcode is not yet linked.
Water hardness
3.2 °dH
Hardness range soft
| Parameter | Value | Parametric value | Share of the parametric value | Reference |
|---|---|---|---|---|
| Nitrate | 9 mg/l | 50 mg/l | 18 % | Mean · Wasserbehälter Hemgenberg: Berzbuir, Birgel, Kufferath |
| Sulphate | 28 mg/l | 250 mg/l | 11 % | Mean · Wasserbehälter Hemgenberg: Berzbuir, Birgel, Kufferath |
| Sodium | 0,27 mmol/l | 200 mg/l | — | Mean · Wasserbehälter Hemgenberg: Berzbuir, Birgel, Kufferath |
Show all recorded parameters (15 — most recent value per parameter)
Chemical parameters (1)
| Parameter | Value | Parametric value | Share of the parametric value | Reference |
|---|---|---|---|---|
| Nitrate | 9 mg/l | 50 mg/l | 18 % | Mean · Wasserbehälter Hemgenberg: Berzbuir, Birgel, Kufferath |
Indicator parameters (4)
| Parameter | Value | Parametric value | Share of the parametric value | Reference |
|---|---|---|---|---|
| Chloride | 11 mg/l | 250 mg/l | 4 % | Mean · Wasserbehälter Hemgenberg: Berzbuir, Birgel, Kufferath |
| pH | 8,88 | 6,5–9,5 | — | Mean · Wasserbehälter Hemgenberg: Berzbuir, Birgel, Kufferath |
| Sodium | 0,27 mmol/l | 200 mg/l | — | Mean · Wasserbehälter Hemgenberg: Berzbuir, Birgel, Kufferath |
| Sulphate | 28 mg/l | 250 mg/l | 11 % | Mean · Wasserbehälter Hemgenberg: Berzbuir, Birgel, Kufferath |
Further parameters (10)
| Parameter | Value | Parametric value | Share of the parametric value | Reference |
|---|---|---|---|---|
| Acid capacity to pH 4.3 | 0,52 mmol/l | — | — | Mean · Wasserbehälter Hemgenberg: Berzbuir, Birgel, Kufferath |
| Base capacity to pH 8.2 | 0,02 mmol/l | — | — | Mean · Wasserbehälter Hemgenberg: Berzbuir, Birgel, Kufferath |
| Calcium | 0,40 mmol/l | — | — | Mean · Wasserbehälter Hemgenberg: Berzbuir, Birgel, Kufferath |
| Carbonate hardness | 1,3 °dH | — | — | Mean · Wasserbehälter Hemgenberg: Berzbuir, Birgel, Kufferath |
| Magnesium | 0,18 mmol/l | — | — | Mean · Wasserbehälter Hemgenberg: Berzbuir, Birgel, Kufferath |
| Non-carbonate hardness | 1,9 °dH | — | — | Mean · Wasserbehälter Hemgenberg: Berzbuir, Birgel, Kufferath |
| Oxygen | 11,1 mg/l | — | — | Mean · Wasserbehälter Hemgenberg: Berzbuir, Birgel, Kufferath |
| Phosphate | <0,05 mg/l below limit of quantification | — | — | Mean · Wasserbehälter Hemgenberg: Berzbuir, Birgel, Kufferath |
| Potassium | 0,04 mmol/l | — | — | Mean · Wasserbehälter Hemgenberg: Berzbuir, Birgel, Kufferath |
| Total hardness | 3,2 °dH | — | — | Mean · Wasserbehälter Hemgenberg: Berzbuir, Birgel, Kufferath |
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-dueren.de/fileadmin/user_upload/2025_Haerteliste_neu.pdf · Juli 2024 bis Juni 2025 · retrieved on 11/07/2026
Postcodes in this zone: 52349 , 52351 , 52353 , 52355
Wasserbehälter Kirmesplatz: Arnoldsweiler, Birkesdorf, Düren-Zentrum, Gürzenich, Hoven, Mariaweiler, Merken, Merzenich, Morschenich-Neu, Rölsdorf
Stadtwerke Düren (SWD)Assigned via the water supplier — the exact supply zone boundary within the postcode is not yet linked.
Water hardness
9.5 °dH
Hardness range medium
| Parameter | Value | Parametric value | Share of the parametric value | Reference |
|---|---|---|---|---|
| Nitrate | 21 mg/l | 50 mg/l | 42 % | Mean · Wasserbehälter Kirmesplatz: Arnoldsweiler, Birkesdorf, Düren-Zentrum, Gürzenich, Hoven, Mariaweiler, Merken, Merzenich, Morschenich-Neu, Rölsdorf |
| Sulphate | 51 mg/l | 250 mg/l | 20 % | Mean · Wasserbehälter Kirmesplatz: Arnoldsweiler, Birkesdorf, Düren-Zentrum, Gürzenich, Hoven, Mariaweiler, Merken, Merzenich, Morschenich-Neu, Rölsdorf |
| Sodium | 1,21 mmol/l | 200 mg/l | — | Mean · Wasserbehälter Kirmesplatz: Arnoldsweiler, Birkesdorf, Düren-Zentrum, Gürzenich, Hoven, Mariaweiler, Merken, Merzenich, Morschenich-Neu, Rölsdorf |
Show all recorded parameters (15 — most recent value per parameter)
Chemical parameters (1)
| Parameter | Value | Parametric value | Share of the parametric value | Reference |
|---|---|---|---|---|
| Nitrate | 21 mg/l | 50 mg/l | 42 % | Mean · Wasserbehälter Kirmesplatz: Arnoldsweiler, Birkesdorf, Düren-Zentrum, Gürzenich, Hoven, Mariaweiler, Merken, Merzenich, Morschenich-Neu, Rölsdorf |
Indicator parameters (4)
| Parameter | Value | Parametric value | Share of the parametric value | Reference |
|---|---|---|---|---|
| Chloride | 33 mg/l | 250 mg/l | 13 % | Mean · Wasserbehälter Kirmesplatz: Arnoldsweiler, Birkesdorf, Düren-Zentrum, Gürzenich, Hoven, Mariaweiler, Merken, Merzenich, Morschenich-Neu, Rölsdorf |
| pH | 8,05 | 6,5–9,5 | — | Mean · Wasserbehälter Kirmesplatz: Arnoldsweiler, Birkesdorf, Düren-Zentrum, Gürzenich, Hoven, Mariaweiler, Merken, Merzenich, Morschenich-Neu, Rölsdorf |
| Sodium | 1,21 mmol/l | 200 mg/l | — | Mean · Wasserbehälter Kirmesplatz: Arnoldsweiler, Birkesdorf, Düren-Zentrum, Gürzenich, Hoven, Mariaweiler, Merken, Merzenich, Morschenich-Neu, Rölsdorf |
| Sulphate | 51 mg/l | 250 mg/l | 20 % | Mean · Wasserbehälter Kirmesplatz: Arnoldsweiler, Birkesdorf, Düren-Zentrum, Gürzenich, Hoven, Mariaweiler, Merken, Merzenich, Morschenich-Neu, Rölsdorf |
Further parameters (10)
| Parameter | Value | Parametric value | Share of the parametric value | Reference |
|---|---|---|---|---|
| Acid capacity to pH 4.3 | 2,64 mmol/l | — | — | Mean · Wasserbehälter Kirmesplatz: Arnoldsweiler, Birkesdorf, Düren-Zentrum, Gürzenich, Hoven, Mariaweiler, Merken, Merzenich, Morschenich-Neu, Rölsdorf |
| Base capacity to pH 8.2 | 0,07 mmol/l | — | — | Mean · Wasserbehälter Kirmesplatz: Arnoldsweiler, Birkesdorf, Düren-Zentrum, Gürzenich, Hoven, Mariaweiler, Merken, Merzenich, Morschenich-Neu, Rölsdorf |
| Calcium | 1,29 mmol/l | — | — | Mean · Wasserbehälter Kirmesplatz: Arnoldsweiler, Birkesdorf, Düren-Zentrum, Gürzenich, Hoven, Mariaweiler, Merken, Merzenich, Morschenich-Neu, Rölsdorf |
| Carbonate hardness | 7,2 °dH | — | — | Mean · Wasserbehälter Kirmesplatz: Arnoldsweiler, Birkesdorf, Düren-Zentrum, Gürzenich, Hoven, Mariaweiler, Merken, Merzenich, Morschenich-Neu, Rölsdorf |
| Magnesium | 0,40 mmol/l | — | — | Mean · Wasserbehälter Kirmesplatz: Arnoldsweiler, Birkesdorf, Düren-Zentrum, Gürzenich, Hoven, Mariaweiler, Merken, Merzenich, Morschenich-Neu, Rölsdorf |
| Non-carbonate hardness | 2,3 °dH | — | — | Mean · Wasserbehälter Kirmesplatz: Arnoldsweiler, Birkesdorf, Düren-Zentrum, Gürzenich, Hoven, Mariaweiler, Merken, Merzenich, Morschenich-Neu, Rölsdorf |
| Oxygen | 8,6 mg/l | — | — | Mean · Wasserbehälter Kirmesplatz: Arnoldsweiler, Birkesdorf, Düren-Zentrum, Gürzenich, Hoven, Mariaweiler, Merken, Merzenich, Morschenich-Neu, Rölsdorf |
| Phosphate | <0,05 mg/l below limit of quantification | — | — | Mean · Wasserbehälter Kirmesplatz: Arnoldsweiler, Birkesdorf, Düren-Zentrum, Gürzenich, Hoven, Mariaweiler, Merken, Merzenich, Morschenich-Neu, Rölsdorf |
| Potassium | 0,07 mmol/l | — | — | Mean · Wasserbehälter Kirmesplatz: Arnoldsweiler, Birkesdorf, Düren-Zentrum, Gürzenich, Hoven, Mariaweiler, Merken, Merzenich, Morschenich-Neu, Rölsdorf |
| Total hardness | 9,5 °dH | — | — | Mean · Wasserbehälter Kirmesplatz: Arnoldsweiler, Birkesdorf, Düren-Zentrum, Gürzenich, Hoven, Mariaweiler, Merken, Merzenich, Morschenich-Neu, Rölsdorf |
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-dueren.de/fileadmin/user_upload/2025_Haerteliste_neu.pdf · Juli 2024 bis Juni 2025 · retrieved on 11/07/2026
Postcodes in this zone: 52349 , 52351 , 52353 , 52355
WB Hemgenberg / WB Kirmesplatz: Krauthausen, Lendersdorf, Niederau
Stadtwerke Düren (SWD)Assigned via the water supplier — the exact supply zone boundary within the postcode is not yet linked.
Water hardness
5.1 °dH
Hardness range soft
| Parameter | Value | Parametric value | Share of the parametric value | Reference |
|---|---|---|---|---|
| Nitrate | 12 mg/l | 50 mg/l | 24 % | Mean · WB Hemgenberg / WB Kirmesplatz: Krauthausen, Lendersdorf, Niederau |
| Sulphate | 35 mg/l | 250 mg/l | 14 % | Mean · WB Hemgenberg / WB Kirmesplatz: Krauthausen, Lendersdorf, Niederau |
| Sodium | 0,51 mmol/l | 200 mg/l | — | Mean · WB Hemgenberg / WB Kirmesplatz: Krauthausen, Lendersdorf, Niederau |
Show all recorded parameters (15 — most recent value per parameter)
Chemical parameters (1)
| Parameter | Value | Parametric value | Share of the parametric value | Reference |
|---|---|---|---|---|
| Nitrate | 12 mg/l | 50 mg/l | 24 % | Mean · WB Hemgenberg / WB Kirmesplatz: Krauthausen, Lendersdorf, Niederau |
Indicator parameters (4)
| Parameter | Value | Parametric value | Share of the parametric value | Reference |
|---|---|---|---|---|
| Chloride | 17 mg/l | 250 mg/l | 7 % | Mean · WB Hemgenberg / WB Kirmesplatz: Krauthausen, Lendersdorf, Niederau |
| pH | 8,35 | 6,5–9,5 | — | Mean · WB Hemgenberg / WB Kirmesplatz: Krauthausen, Lendersdorf, Niederau |
| Sodium | 0,51 mmol/l | 200 mg/l | — | Mean · WB Hemgenberg / WB Kirmesplatz: Krauthausen, Lendersdorf, Niederau |
| Sulphate | 35 mg/l | 250 mg/l | 14 % | Mean · WB Hemgenberg / WB Kirmesplatz: Krauthausen, Lendersdorf, Niederau |
Further parameters (10)
| Parameter | Value | Parametric value | Share of the parametric value | Reference |
|---|---|---|---|---|
| Acid capacity to pH 4.3 | 1,12 mmol/l | — | — | Mean · WB Hemgenberg / WB Kirmesplatz: Krauthausen, Lendersdorf, Niederau |
| Base capacity to pH 8.2 | 0,05 mmol/l | — | — | Mean · WB Hemgenberg / WB Kirmesplatz: Krauthausen, Lendersdorf, Niederau |
| Calcium | 0,65 mmol/l | — | — | Mean · WB Hemgenberg / WB Kirmesplatz: Krauthausen, Lendersdorf, Niederau |
| Carbonate hardness | 3,0 °dH | — | — | Mean · WB Hemgenberg / WB Kirmesplatz: Krauthausen, Lendersdorf, Niederau |
| Magnesium | 0,25 mmol/l | — | — | Mean · WB Hemgenberg / WB Kirmesplatz: Krauthausen, Lendersdorf, Niederau |
| Non-carbonate hardness | 2,1 °dH | — | — | Mean · WB Hemgenberg / WB Kirmesplatz: Krauthausen, Lendersdorf, Niederau |
| Oxygen | 10,1 mg/l | — | — | Mean · WB Hemgenberg / WB Kirmesplatz: Krauthausen, Lendersdorf, Niederau |
| Phosphate | <0,05 mg/l below limit of quantification | — | — | Mean · WB Hemgenberg / WB Kirmesplatz: Krauthausen, Lendersdorf, Niederau |
| Potassium | 0,05 mmol/l | — | — | Mean · WB Hemgenberg / WB Kirmesplatz: Krauthausen, Lendersdorf, Niederau |
| Total hardness | 5,1 °dH | — | — | Mean · WB Hemgenberg / WB Kirmesplatz: Krauthausen, Lendersdorf, Niederau |
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-dueren.de/fileadmin/user_upload/2025_Haerteliste_neu.pdf · Juli 2024 bis Juni 2025 · retrieved on 11/07/2026
Postcodes in this zone: 52349 , 52351 , 52353 , 52355
52379 Langerwehe-Wenau, L12 (Wald) / Entnahmestelle: HB Schönthal Ablauf, PNV KW
Wasserleitungszweckverband LangerweheAssigned via the water supplier — the exact supply zone boundary within the postcode is not yet linked.
Water hardness
7.3 °dH
Hardness range soft
| Parameter | Value | Parametric value | Share of the parametric value | Reference |
|---|---|---|---|---|
| Nitrate | 4,3 mg/l | 50 mg/l | 9 % | Single value |
| Escherichia coli (E. coli) | 0 MPN/100 ml | 0/100 ml | — | Single value |
| Sulphate | 53 mg/l | 250 mg/l | 21 % | Single value |
| Sodium | 7,0 mg/l | 200 mg/l | 3 % | Single value |
Show all recorded parameters (38 — most recent value per parameter)
Microbiology (2)
| Parameter | Value | Parametric value | Share of the parametric value | Reference |
|---|---|---|---|---|
| Escherichia coli (E. coli) | 0 MPN/100 ml | 0/100 ml | — | Single value |
| Intestinal enterococci | 0 KBE/100 ml | 0/100 ml | — | Single value |
Chemical parameters (10)
| Parameter | Value | Parametric value | Share of the parametric value | Reference |
|---|---|---|---|---|
| 1,2-dichloroethane | <0,0007 mg/l below limit of quantification | 3 µg/l | < 23 % * | Single value |
| Boron | 0,01 mg/l | 1 mg/l | 1 % | Single value |
| Bromate | <0,001 mg/l below limit of quantification | 10 µg/l | < 10 % * | Single value |
| Chromium | <0,0005 mg/l below limit of quantification | 25 µg/l | < 2 % * | Single value |
| Fluoride | 0,05 mg/l | 1.5 mg/l | 3 % | Single value |
| Mercury | <0,0001 mg/l below limit of quantification | 1 µg/l | < 10 % * | Single value |
| Nitrate | 4,3 mg/l | 50 mg/l | 9 % | Single value |
| Nitrite | <0,005 mg/l below limit of quantification | 0.5 mg/l | < 1 % * | Single value |
| Tetrachloroethene | <0,0003 mg/l below limit of quantification | — | — | Single value |
| Trichloroethene | <0,0003 mg/l below limit of quantification | — | — | 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 (16)
| Parameter | Value | Parametric value | Share of the parametric value | Reference |
|---|---|---|---|---|
| Aluminium | <0,01 mg/l below limit of quantification | 0.2 mg/l | < 5 % * | Single value |
| Ammonium | <0,02 mg/l below limit of quantification | 0.5 mg/l | < 4 % * | Single value |
| Calcite dissolution capacity | 5,3↑ mg/l | 5 mg/l CaCO3 | — | Single value |
| Chloride | 13 mg/l | 250 mg/l | 5 % | Single value |
| Clostridium perfringens (including spores) | 0 KBE/100 ml | 0/100 ml | — | Single value |
| Coliform bacteria | 0 MPN/100 ml | 0/100 ml | — | Single value |
| Colour | <0,05 1/m below limit of quantification | 0.5 m⁻¹ | — | Single value |
| Iron | <0,01 mg/l below limit of quantification | 0.2 mg/l | < 5 % * | Single value |
| Manganese | <0,005 mg/l below limit of quantification | 50 µg/l | < 10 % * | Single value |
| Odour | ohne | für den Verbraucher annehmbar | — | Single value |
| pH | 7,74 | 6,5–9,5 | — | Single value |
| Sodium | 7,0 mg/l | 200 mg/l | 3 % | Single value |
| Sulphate | 53 mg/l | 250 mg/l | 21 % | Single value |
| Taste | ohne | für den Verbraucher annehmbar | — | Single value |
| Total organic carbon (TOC) | 0,74 mg/l | ohne anormale Veränderung | — | Single value |
| Turbidity | 0,068 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.
Treatment substances (1)
| Parameter | Value | Parametric value | Share of the parametric value | Reference |
|---|---|---|---|---|
| Total chlorine | <0,05 mg/l below limit of quantification | — | — | Single value |
Further parameters (9)
| Parameter | Value | Parametric value | Share of the parametric value | Reference |
|---|---|---|---|---|
| Acid capacity to pH 4.3 | 1,68 mmol/l | — | — | Single value |
| Base capacity to pH 8.2 | 0,07 mmol/l | — | — | Single value |
| Calcium | 32,2 mg/l | — | — | Single value |
| Carbonate hardness | 4,5 °dH | — | — | Single value |
| Magnesium | 12,2 mg/l | — | — | Single value |
| Oxygen | 10,5 mg/l | — | — | Single value |
| Phosphate | 0,16 mg/l | — | — | Single value |
| Potassium | 1,7 mg/l | — | — | Single value |
| Total hardness | 7,3 °dH | — | — | 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.wzv-langerwehe.de/wp-content/uploads/2026/01/Trinkwasseranalyse-12.2025.pdf · 12.01.2026 · 02.12.2025 – 12.01.2026 · retrieved on 11/07/2026
Frequently asked questions about drinking water in Düren
- How hard is the water in Düren?
- Stadtwerke Düren (SWD) publishes a total hardness of 8.2 °dH for the supply zone Derichsweiler (Lieferant: WZV Langerwehe) (hardness range soft). The hardness range is a classification under the German Detergents and Cleaning Products Act (soft below 8,4 °dH, medium 8,4 to 14 °dH, hard above that) and not a quality verdict — it indicates how much calcium and magnesium is dissolved in the water. Basis: Publication by the water supplier, retrieved on 11/07/2026.
- How much nitrate is in the drinking water in Düren?
- Stadtwerke Düren (SWD) publishes a nitrate value of 8,4 mg/l for the supply zone Derichsweiler (Lieferant: WZV Langerwehe). The statutory parametric value is 50 mg/l; the measured value represents 17 % of the parametric value. Basis: Publication by the water supplier, retrieved on 11/07/2026.
- Who supplies the drinking water in Düren?
- Stadtwerke Düren (SWD). The values shown here come from the supply zone Derichsweiler (Lieferant: WZV Langerwehe) 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.