Emissions to water by consumers in the Netherlands, 1990-2001
| 1990 | 1995 | 1999 | 2000 | 2001 | of which | ||
| direct | indirect | ||||||
| Nutrients | 1 000 kg | ||||||
| Nitrogen (as N total) | 49 800 | 52 600 | 54 200 | 54 600 | 55 100 | 542 | 54 600 |
| Phosphorus (as P total) | 5 310 | 5 610 | 5 780 | 5 830 | 5 880 | 58 | 5 820 |
| Metals | |||||||
| Cadmium (Cd) | 0.712 | 0.754 | 0.779 | 0.785 | 0.792 | 0.006 | 0.786 |
| Chromium (Cr) | 2.85 | 3.02 | 3.11 | 3.14 | 3.17 | 0.022 | 3.15 |
| Copper (Cu) | 113 | 122 | 136 | 127 | 130 | 2.52 | 127 |
| Mercury (Hg) | 0.271 | 0.271 | 0.28 | 0.282 | 0.285 | 0.002 | 0.283 |
| Lead (Pb) | 68.4 | 71.6 | 73.6 | 74.3 | 75 | 1.07 | 73.9 |
| Nickel (Ni) | 7.12 | 7.54 | 7.79 | 7.85 | 7.92 | 0.055 | 7.86 |
| Zinc (Zn) | 253 | 230 | 212 | 212 | 209 | 7.49 | 201 |
| Source: CCDM (2003). | CBS/EDC/Sep03/0139 | ||||||
Developments and measures
Emissions to water by consumers are caused, on the one hand, directly through urine and faeces (this includes nutrients) and, on the other, by the use of products and the use of construction metals in houses. Water pipes and fireworks are sources of copper emissions. Lead comes mainly from cover flashings on housing and water pipes. Roof gutter corrosion results in zinc emissions. Product improvements will be achieved in the years to come through agreements with the construction metals industry. One of the focus areas here will be new metal alloys, the use of coatings and alternative materials. In time, this should result in emission reductions of approximately 50% (VROM, 2001).
What are direct and indirect emissions?
The table lists the emissions from the various sources. It shows both direct emissions to surface water and indirect discharges to the sewer system. Discharges to the sewer system only reach surface water after treatment; they are therefore indirect. Since a portion of these substances is removed by water treatment plants, the ultimate burden on surface water is lower.
