In the past thirty years, the government has taken measures to reduce nitrogen and phosphorus concentrations in the water. This has improved the quality of the ground and surface water. But the water quality is not yet sufficient everywhere.
The nitrate concentration is too high in the top one meter of the groundwater of more than half of the farms in the sand and loess regions. This also applies to the top meter of groundwater in more than thirty of the approximately 200 groundwater protection areas. Also, a large part of the surface waters does not yet meet the desired quality and the concentrations of nitrogen and phosphorus are too high.
Nitrogen and phosphorus are substances in manure that farms use to make crops grow better. Excess nitrogen and phosphorus can wash away to ground and surface water. Nitrate is one of the forms in which nitrogen occurs in the soil and water.
The improved water quality is mainly due to the fact that farmers have started to use less and less manure. This reduced too much nitrogen and phosphorus in the soil. This also means that less nitrate sinks with rainwater to deeper layers in the soil and thus ends up in the groundwater. The less nitrogen and phosphorus there is in the soil and groundwater, the less will flow to the surface water.
It is important to have clean ground and surface water that can be turned into drinking water. Clean surface water also ensures that more different plants and animals can live in the water.
Monitoring of nitrate in surface water has recently become reliable and affordable with the NICO sensor. This nitrate sensor has been tested by the RIVM. The NICO sensor combines reliability with user-friendliness and low operational costs. The sensor uses optical UV absorption technology for the determination of nitrate concentrations in fresh surface and ground water. The calculation of nitrate from the filtered absorption spectrum includes compensations for turbidity and organic disturbances. Nitrate measurements are available in real-time in combination with our data loggers. The optional wiper reduces maintenance requirements and extends uptime for continuous measurements.