
An excess of phosphate in the soil and the surface water is not good. On land, an excess of phosphate leads to overgrowth of rare plants. Generous fertilisation in the Netherlands and also the discharge of phosphates via waste water in the past meant that a great deal of phosphate was absorbed by Dutch rivers and lakes. This resulted in algae blooms and suffocation of other life forms. The phosphate in the sewer system originates in human waste, but washing powders also used to contain high levels of phosphate. Washing powder now contains almost no phosphates and almost all water purification plants are fitted with systems that separate the phosphate from the waste water. This phosphate settles in the sludge that is processed by a number of enterprises, including Slibverwerking Noord-Brabant.