This pilot study began in September 2016 at WTW Lövo of Stockholm Vatten, and investigated the use of SIX®, ozone, ILCA®, and CeraMac® membrane filtration for treating water from Lake Mälaren. This lake is the biggest in Europe and the main source for the drinking water utilities in the Stockholm area. While the overall water quality of this lake is excellent, it contains relatively high levels of humic and fulvic acids which give a brownish color to the water. Pilot results showed excellent organics removal by SIX®, and the need for coagulation for sustainable membrane operation. A second trial was then performed at Norrvatten, at the WTW Görvalnverket site.