Composting application - Sludge

According to § 38 of the Waste Management Regulations of the Vaasa Region, self-treatment of sewage sludge always requires prior written notification to the waste management authority.

Composting is permitted if the amount of sludge generated is small and its treatment on the property does not pose a risk or harm to the environment or human health. The amount of sludge is considered small if it is less than 50 litres per emptying and less than 100 litres per year. 

Dry toilet waste, pet excrement, and sludge from small-scale treatment plants referred to in § 38 of the Waste Management Regulations may only be composted in a closed and well-ventilated composter designed for this purpose. The composter must be protected from pests and prevent runoff water from seeping into the ground. The composter must be kept in proper condition and maintained regularly according to the instructions. The composting time for fecal waste is at least one year.  

Different wastewater treatment and interim storage systems

Cesspool – A closed tank used for temporary storage of wastewater. The tank is emptied by a vacuum truck.

Small-scale treatment plant – Either constructed on site or factory-made for wastewater treatment. Depending on the system, sludge is either removed by a vacuum truck or collected in a compostable sludge bag.

Septic tank – A pre-treatment system that separates solids from water. It usually builds on multiple steps . The treated water is then directed either to soil treatment or to a small-scale treatment plant.

Phosphorus filter – Can be installed after the soil treatment system if needed to meet the treatment requirements. 

Greywater filter – Used to treat greywater (water that does not contain urine or fecals). Different filtration materials are used, such as stone and peat.