What is sludge?

   According to the modern Icelandic dictionary, the term sludge is defined as: "Impurity that separates from sewage water". 

To explain the concept a little more, we can think of all the waste and things that go down toilets and drains. All the things that go through there are collected in a septic tank, but there is a tank that collects all the sediment/bottom layer and all the water that comes from drains (sewer water). When the liquid (sewage water) is separated from the sediment, by filtration or emulsification, solid organic waste remains and is called sludge. 

Utilization of sludge

The municipalities of Ásahreppur, Bláskógabyggð, Flóahreppur, Grímsnes- and Grafningshreppur, Hrunamannahreppur and Skeiða- and Gnúpverjahreppur are responsible for the sludge project.
The project is a joint project of the local authorities, Landgræðinn and the Southern Health Authority. The project consists of the municipalities taking care of the cleaning of tanks, and each tank must be cleaned every three years. 

The sludge is collected by a sludge truck, which then dumps it into a calk truck where it is mixed with calk and sometimes also grass seeds. Once the sludge has been calcified, it is spread to a special distribution area where it is used for reclamation. The municipalities operate a sludge receiving station in Flúður, where the sludge is received and processed. 

The sludge project does not clean the septictank during the winter, the cleaning of the septictanks starts in the spring. Work begins in the spring as soon as it is possible to take the sludge to the reclamation area and work as far into the fall as possible due to weather and conditions.