Background Conventional large wastewater treatment plants employing mechanical, chemical and biological treatment even after treatment still produce high levels of heavy metals and other dangerous chemical elements in the treated wastewater. The sludge obtained does not permit the recovery of nutritious material due to the danger of the pollutants being released into the environment. The coastal area of the Municipality of Hammaroe, which originally mainly consisted of holiday cottages, is now populated with permanent residences that employ water-based sewage systems. However, the geology of the coastal areas are extremely delicate: the ground is rocky and the surrounding soil comprises clay and dense moraine, thus the risk of leakage of nutrients from the existing private wastewater systems into Lake Vaenern, is high, and furthermore, there is a high risk of microbial pollution of the existing water wells. Objectives Overall, the project hoped to develop a method for recycling wastewater and organic waste for small spread-out settlements not connected to a central community wastewater treatment plant in a way that would minimise the need for extensive piping systems. Specifically, the project aimed to demonstrate an ecologically sustainable method for recycling wastewater and organic household waste, involving innovative biological technologies and processes, where all organic portions are treated together and transformed into usable resources. The project aimed to construct two treatment plants: one main treatment plant and another local mini-plant. The households involved in the project were to be connected to the mini-plant via a pipeline. Water treatment integrated with wet compost processes were to be carried out at the main plant, whereas at the local plant, water would be treated with the resultant sludge being transported to the main plant. Results To demonstrate and evaluate the method, one local mini-plant and one main plant were built. The mini-plant treats the wastewater from around 40 households. The sludge produced at the mini-plant is then transported to the main plant along with other organic waste from the area and incorporated into its recovery process, ‘Wetcompost’. Wetcompost is a recently developed method for treating organic waste and sludge from wastewater treatment plants. Wetcompost aims for hygienic treatment, decomposition of organic materials into minerals and transformation of nutritious material to nutrients. In the first step, all incoming material is collected and mixed. The mixed organic material is pumped into the Wetcompost reactor under strong oxygenation, and the temperature is increased to approximately 50–60ºC. When the organic materials have decomposed into minerals, the material is pumped into reed-beds for dewatering. The nutrient-rich reject-water is pumped to the storage basin. The main plant was built in Sättersviken. In order to test the main plant, the wastewater systems from around 450 households were disconnected from the old community wastewater system and connected to the new main plant. In selected households in the area, waste disposal units were installed for treating the organic household waste. The wastewater pipelines transport both wastewater and organic household waste. The main plant combines wastewater treatment with the recovery of nutrients from sludge and organic waste. The mini plants treat the wastewater locally, which means that long and expensive pipe-laying in sensitive environment is avoided. The sludge that is produced in the mini plants undergoes final treatment at the main plant. The end products from the plant are clean water, a fertiliser with harmless bacteria content and a sludge residue that can be used as a soil improver. However, despite the demonstration success, the project failed to implement an evaluation phase or collect data to assess the efficiency of the treatment process and to estimate the reduction of the pollution load to the environment. Expected results of pollution reduction nonetheless were very promising; conceptually this method was anticipated to deliver 95% removal of phosphorus, 98% removal of nitrogen and 99% removal of BOD (Biological Oxygen Demand). The total costs for all installations of the main wastewater treatment plant were approximately €800/p.e. (person equivalents). This included a highly efficient nitrogen removal capacity, not normally available in plants of this size. The total costs for all installations of the satellite wastewater treatment plant were approximately €1450/p.e.