Quality of our tap water

Waternet produces and supplies high quality tap water. Your tap water is checked by a laboratory on a daily basis. We check the level of oxygen, fluoride, etc. in the water. We also test the taste, smell and temperature of the tap water. Additionally, we check the clarity of the water and we measure how soft or hard the water is.

Does our tap water meet the legal requirements? This can be found in the overview below. The overview compares the data from the laboratory with the legal requirements. We publish the results at the end of every quarter.

  • The left-hand side of the table shows the amount of a specific substance in our water.
  • The right-hand side of the table shows the maximum permitted amount of substance in the water. Or the minimum required amount.

This shows that our water meets the legal requirements.

 

Results of water quality measurement, 3rd quarter of 2017
Measurement Measurement unitLowest measurementAverage measurementHighest measurementRegulatory minimum amountRegulatory maximum amount
Aluminium µg/l 1,1 3,7 6,9   200
Arseen µg/l <0.5 1,0 2,4   10
Boor mg/l 0,02 0,04 0,05   0,5
Calcium mg/l 38 41 46   -
Chloride mg/l 58 75 93   150 **
Koolstofdioxide mg/l 1,7 2,5 3,5   -
EGV (elek. geleid.verm. 20°C) mS/m 44,3 53,1 58,1   <125
Fluoride mg/l 0,05 0,08 0,12   1,0
IJzer mg/l <0.01 <0.01 0,02   0,2
Troebeling FTU <0.03 <0.03 0,14   1
Geur (kwalitatief)   afwezig afwezig afwezig   ****
Waterstofcarbonaat mg/l 159 175 194 >60  
Kwik µg/l <0.02 <0.02 <0.02   1
Totale hardheid mmol/l 1,27 1,37 1,49 >1.0  
Totale hardheid °Duits 7,1 7,7 8,3 >5.6  
Kleurgetal mg/l Pt <1 1 2   20
Magnesium mg/l 6,1 8,1 10,5   -
Mangaan mg/l <0.01 <0.01 <0.01   0,05
Natrium mg/l 50 62 77   150
Ammonium mg/l NH4 <0.02 <0.02 0,03   0,2
Nitriet mg/l NO2 <0.007 <0.007 0,008   0,1
Nitraat mg/l NO3 1,21 3,08 4,46   50
Zuurstof, opgelost mg/l 6,1 7,4 9,0 >2  
pH berekend pH 7,85 8,06 8,25 7,0 9,5
Seleen µg/l <0.5 <0.5 <0.5   10
Verzadigingsindex S.I. Berekend pH 0,18 0,34 0,50 > -0.2  
Smaak (kwalitatief)   afwezig afwezig afwezig   ****
Sulfaat mg/l 6 26 48   150
Temperatuur °C 15,0 17,9 20,7   25
Totaal organisch koolstof mg/l 1,1 2,2 3,3   ****
Aeromonas kvd/100 ml 0 60 434   1000
Clostridium perfringens kvd/100 ml 0 0 0   0
Coli 37°C kvd/100 ml 0 0 0   0
Enterococcen kvd/100 ml 0 0 0   0
Koloniegetal 22 °C * kvd/ml 0 8 207   100 ***
Legionella kvd/l <100 <100 <100   <100

* Geometrisch kwartaalgemiddelde koloniegetal (Geometric quarterly average of the colony count) 22°C = 3.3
** norm jaargemiddelde (annual average)
*** norm geometrisch jaargemiddelde (geometric annual average)
**** geen abnormale verandering (no abnormal change)