The system involved active participation by the citizens in a total recycling through agriculture and aquaculture. Awareness campaigns encouraged
people only to flush harmless wastes that could be recycled.
In 1929, a wastewater-fed aquaculture for fish production was established (Prein, 1990). The fishfarming
was adapted to the northern climate with a seasonal production period lasting from April
to October. In winter, the wastewater was stored in a lake, while the fish ponds were cleaned. The
Munich system was dimensioned for the entire population of at that time 500,000 p.e. using 200
litres of water per day. The total size of the aquaculture is 233 ha with an annual fish production
of 100-150 tons. Depuration studies on the fish showed that depuration lasting up to one year
was effective for Cd and Pb but not for Hg and PCBs.
The Munich fish pond system is still in operation. Today a sophisticated pre-treatment is installed,
which has changed the system from a wastewater treatment facility to a polishing facility, i.e. tertiary
treatment. It is high time to use the Munich type of legacy in order to enforce EU environmental
policies.