SW Umwelttechnik Stoiser & Wolschner AG develops and produces precast concrete elements for infrastructure construction in Austria, Hungary, and Romania, Slovakia, and Bulgaria. It offers mineral oil separators, rainwater utilization systems, small sewage treatment plants, and prestressed concrete tanks; drinking water tanks; retaining wall systems; manholes; and pump wells. The company was founded in 1910 and is based in Klagenfurt, Austria.