Discharge of oyxgen-demanding substances and load on surface water in the Netherlands, flowchart 2000

The burden on surface water generated by oxygen-demanding substances has fallen again. This is primarily the result of improvements in the efficiency of urban wastewater treatment plants.

Note on flowchart

The transport difference is the difference between total discharge to urban wastewater treatment plants (UWWTPs), calculated on the basis of levies, and the actual amount of pollution measured in UWWTP influent. The major reason for the difference is the inflow of extra pollution to the sewer system through run-off water from hard surfaces. These pollutants are not included in the discharges from households and companies.
The pollution value (expressed as inhabitant equivalents) is the quantity of oxygen-demanding substances for which the oxygen demand in aerobic degradation equals that of the wastewater of one inhabitant per day.
A time series for the development of emissions of oxygen-demanding substances and burden on surface water is presented elsewhere.

References

• CBS (2003). Statline. Waterkwaliteitsbeheer, Zuivering van afvalwater. Statistics Netherlands, Voorburg/Heerlen.

Relevant sections and indicators in the Environmental Data Compendium

• Guide to societal developments relating to Actors in the water chain
• Discharges into water and burden on surface water in the Netherlands, 1990, 1995, 1999 and 2000
• Guide to Environmental theme of Eutrophication

Relevant information outside of the Environmental Data Compendium

• More information about the discharge of oxygen-demanding substances and the burden on surface water can be found on Statline (Statistics Netherlands).