The Federal German Water Law of 1976 postulated for the first time that a license for the discharge of wastewater into public water courses might only be granted when the wastewater prior to the discharge is treated according to the actual standards. Also since 1976 it was decided that for the residual pollution of wastewater a pollution fee has to be paid.

Assuming certain loads per capita one can calculate that presently three pollution units have to be paid per capita and year for untreated domestic wastewater. One pollution unit is assessed with 50 DM per year in 1991 but the price will be increased to 90 DM per year in future.

Since the pollution units encompass COD, nitrogen, phosphorus, heavy metals and chlorinated carbon compounds the pollution unit is a very good tool to compare the effectiveness of treatment. For different drainage systems one can also calculate the residual pollution units per litre and second for low flow conditions.

This content is only available as a PDF.
You do not currently have access to this content.