One of problems complicating the delivery of clean drinking water is the excessive use of manure. Because of excessive use of nitrate-rich manure in agriculture during previous decennia, large quantities of nitrate have leached through the soil to the groundwater. Nitrate pollution poses serious problems, especially for the water supply companies, amongst others because of heavy metals mixing with water.

Next to nitrate, the delivery of clean drinking water is also complicated by higher concentrations of sulfates in the water, and because of hard  water. Hard water causes scale in for example washing machines and water supply companies are more and more softening their water.

Pesticides also influence the water quality. They are difficult to trace and costs of monitoring and treatment are extremely high. Often, 15 - 20% of the delivery costs for drinking water are spent on this purpose. 

Water can be polluted by acid substances as well. pH correcting substances can be used for treatment.  The drinking water industry will have to specialise further. Pollution as well as costs for treatment are increasing. However, the Dutch consumer stil doesn't pay an extraordinary amount of money for its drinkwater, but keeping the quality of drinking water at a constant level, while the concentration of pollutants becomes higher and higher will unavoidably result in higher costs in the future. 

Source: Staatscourant