The thesis reports on Submerged Aerated Filter (SAF) as a tertiary treatment for carbonaceous removal and nitrification. SAFs are relatively new in wastewater treatment and used where available space is limited and any odour must be avoided. They are common as additional or an add on treatment step to meet new standards. Further development of SAF is needed. Most literature is commercial and further academic studies are necessary. This research investigates the possibility of using natural wool fleece as a SAF biosupport media. Most existing plants use sand or plastic. It was hypothesized that wool fleece would have some potentially desirable effluent treatment properties. These were their hydrophobic characteristics, natural and sustainable origin and a fibrous expanded format. Wool is also a cheap, easily available material. This project is an experimental study to determine whether a filter packed with wool could have a better performance than a standard plastic media to treat municipal pollutants.