Small wastewater treatment plants in Austria - Technologies, management and training of operators

In Austria, about 95% of the population are served by 1865 wastewater treatment plants (WWTPs) with design size >50 population equivalent (PE). Besides, there are about 27′500 small WWTPs with design size less than 50 PE. Among these small WWTPs, the technologies implemented most frequently are about 7020 conventional activated sludge plants, 5560 treatment wetlands and 5240 Sequencing Batch Reactors. About 45% of the small WWTPs have a design size between 5 and 10 PE. It has been shown that design standards for small WWTPs increased the numbers implemented for both technical and nature-based technologies. A permit given from the local authorities is required for operating a small WWTP. If the design of a small WWTPs follows a design standard, the process to get a permit is simplified. Most authorities request that owners of small WWTPs have a maintenance contract with a company and/or that owners/operators have to pass the training course for operators of small WWTPs offered by the Austrian Wastewater and Waste Association (ÖWAV). Within the 1.5 days long training courses, owners/operators gain basic knowledge on wastewater treatment and thus better understand their plant. This should finally result in well operated and maintained small WWTPs. Since the year 2000, more than 200 training course have been held and more than 5500 owners/operators of small WWTPs have been trained.