Ditch water in parts of the country where the bulb industry is concentrated is so polluted that urgent measures need to be taken, according to Leiden University researchers in Monday’s Trouw.

Either there should be an immediate ban on pesticide use in the worst affected areas, or farmers should be stopped from spraying close to water to create a buffer, the researchers say.
The researchers base their claims on water board research which shows that while Dutch water is ‘not at all bad’, in western areas such as Delfland, Rijland and Bommelerwaard the quality is poor.
EU standards
Almost 10% of the water samples taken in the three areas break official water quality standards.
‘We are doing well in the Netherlands… but the use of pesticides is increasing and in some areas which are cultivated very intensively, there are serious problems,’ Leiden professor Geert de Snoo told the paper. ‘Measures must be taken.’
The worst affected areas are centres of the bulb and flower industry, which uses more chemicals than other sectors. On average, bulb growers use 42 kilos of chemicals for every hectare of land under cultivation, compared with average pesticide usage of seven kilos.
Rules introduced in 2001 required growers not to spray within 1.5 metres of a ditch, a measure which led to a 70% improvement in water quality. Since then, however, there has been no improvement.
‘A temporary spray ban would be a way out in areas where the [pollution] standards are broken and allow the ditches and waterways to recover,’ De Snoo said.