Evoqua United States - Canada - EN

Continuous Disinfection of Groundwater Without Chemicals

Karswald has ensured environmentally friendly disinfection through a chemical-free UV system


The waterworks Karswald near the city of Dresden in Germany belongs to the association Bischofswerda-RÖDERAUE and supplies several local areas. During modernization, the water works in Karswald was a focal point with three and a half million Euros invested into a new building. In 2017, the new waterworks Karswald went into operation, the old building was teared off.

In the Karswald water works, 1,900 m3/day of groundwater is provided. The preparation stages are:

• Mechanical ventilation/deacidification

• Iron removal/manganese removal/chemical deacidification in closed filter system

• UV disinfection and chlorination on demand with sodium hypochlorite • Treatment of filter backwash water

• Sludge treatment

A UV system ensures continuous disinfection without the use of chemicals. Taste or odor impairments caused by chlorine are no longer an issue. Thus, the association has an environmentally friendly way of disinfection.


In the planning phase of the new waterworks, a UV system from Evoqua Water Technologies was chosen. By installing a Barrier® S unit, it ensures the minimization requirement of the Drinking Water Ordinance is met.

The design of the UV system is very compact, so that the replacement of the three lamps can take place with little effort. The unit was installed by the company Kopf Umwelt- und Energietechnik, Riesa. The treatment capacity is approx. 130 m³/h.



Disinfection can be warranted without entering additional disinfection by-products in the drinking water system. Odor and taste impairments are thus avoided and the handling of hazardous substances for the operating personnel is eliminated.