The Project REMAC aims to develop ecologically and economically sound sludge management concepts in smaller regional towns.
The project REMAC responds to the specific element for improving the people’s physical living environment by providing new methods for ecologically and economically sustainable concepts for wastewater utility sludge treatments for regional towns in relatively dispersed settlements. In many cases, current sludge treatment practices are not carried out on ecologically or economically solid basis.
In Finland, open-pit composting of the sludges is about to end due to existing environmental permit practices. Finland is nationally supporting biogas production, which is implemented nationally as big-volume anaerobic digestion units. Whilst the increase in biogas production supports environmental sustainability, the dependency on centralized high-volume units forms problems in areas with dispersed population. The amount of fossil fuel needed in transportation of the sludge is high due to transportation of even hundreds of kilometers for both the sludge and the digestate from the biogas production process. Wet digestion is also very water-intensive process increasing the need to transport digestate with high water content after digestion process.
In Russian Karelia, landfilling or open-pit composting of sludge is common practice, leading to uncontrolled methane leakage and leeching of nutrients and possible harmful compounds into soil and nearby waterbodies. There has been a previous investment initiative BIOKOS at Kostomuksha region for developing sludge treatment, based on drying the sludge and incinerating it with woodchip in local district heating plant. The plant is in operation and sludge treatment has been improving due to previous investment, but the drying technologies available during the previous investment are not adequate for effective process. To date sludge is placed to open-pit composting instead of incineration. One problem is also that options for renewing the sludge management without massive investments are not always recognized, nor implemented. Examples of these can be found e.g. in Kondopoga district, where sludges from 5 villages with humidity of 98% are transported. Also, the existing units represent a risk of leaking sludge to nearby waterbodies due to inadequate facilities. This is due to limited availability of technological expertise and systemic understanding on the local context. Also, hand-on understanding on frame conditions related to possible new solutions are not easily available.