Constructed wetlands for wastewater treatment in the Czech Republic

The first constructed wetland (CW) for wastewater treatment was built in the Czech Republic in 1989. This recent survey shows that at the end of 1999 101 systems are in operation and several more are under construction. 95 CWs are designed with sub-surface horizontal flow, 6 systems are hybrid with a combination of vertical and horizontal flow beds. Most systems (56) were designed for the treatment of municipal and domestic sewage while 38 CWs were designed for the treatment of wastewater from combined sewer systems. The most commonly used size of vegetated beds is 1,001-2,500 m2 (31 systems) followed by the area between 51-250 m2 (19%). The area of vegetated bed of the largest system is 4,493 m2. Size distribution is quite evenly spread from very small systems (PE = 3 or 4) up to 1,000 PE. However, most systems (44) were sized to treat wastewater from sources between 101 and 500 PE. The most commonly used macrophyte is Common reed (Phragmites australis) which is used in 34 systems as a monotypic stand and in 44 systems in combination with other macrophytes, most frequently with Reed canarygrass (Phalaris arundinacea) (31 systems) and cattails (Typha spp.) (8 systems).