Classification
UPCE - Water chemistry
UPT - Water pollution control and measurement
15
UPN - Water protection, water quality, clean water
3
UPK - Water resources, water supply
2
USN - Waste water treatment
2
GMAB - Hydrogeochemistry
1
USK - Waste water
1
USKH - Special waste waters
1
USNG - Waste water treatment - biological aspects
1
USNH - Waste water treatment - special methods
1