Sludge management at the treatment plant along with the modernization of the sewerage network in the Słupsk agglomeration
- Total cost of the project: PLN 48,515,041.64
- Co-financing amount from the Cohesion Fund: PLN 20,454,782.82
- Maximum amount of eligible expenditures of the Project: PLN 24,064,450.38
- Co-financing amount in the form of a loan from the Regional Fund for Environmental Protection and Water Management (WFOŚiGW) in Gdańsk: PLN 12,000,000.00
Project Objectives
The general objective of the Project is to increase the capacity to receive and treat a larger volume of pollutant loads, and to optimize the technological process at the wastewater treatment plant—particularly in the field of sludge management, along with reducing gas emissions (including malodorous gases) into the atmosphere. Furthermore, the project involves the modernization of sewerage systems and networks within the agglomeration.
The investment aims to address and solve the following issues and problems:
- To enable the treatment plant to handle an additional stream of pollutant loads in wastewater and from reject water derived from imported sludge, through the construction of an installation for reject water treatment in an SBR reactor;
- To enable the attainment of the required degree of sludge stabilization prior to the composting process. The functioning sludge unit has insufficient capacity. By constructing an additional digestion tank, it is planned to improve the degree of sludge stabilization during the digestion process. Furthermore, it is necessary to increase the efficiency of the sludge thickening process by approx. 30%. The expansion of the machinery room and auxiliary equipment is associated with this task. This will allow for a reduction in the volume of generated sludge and its more efficient further processing in the composting process. These measures will also create opportunities to receive sludge from small treatment plants scheduled for operation by the Company, as well as to establish a rational offer for the so-called co-digestion (co-processing) of other unstabilized sludge from the Słupsk region (insofar as this possibility arises from an appropriate degree of digestion).
- To improve the odor control protection of the composting plant by constructing an under-pile and under-roof extraction system with biofiltration, and limiting ambient emissions by partially enclosing the shelter. The task foresees the partial encapsulation of the composting plant, which will require the implementation of an additional deodorization system for the composting facility.
In order to improve the effectiveness of the composting plant’s deodorization, the implementation of the following solutions has been planned:
- installation of curtains around the shelter, ensuring the closure of open spaces between the roof eaves and the gables;
- installation of an extraction system from beneath the ridge of the shelter;
- modification of the ventilation system layout related to the existing supply fans, enabling the reversible operation of these fans;
- construction of devices for biofiltration of the air extracted from the composting plant shelter.
- To enable the treatment plant to handle an additional stream of imported unstabilized sludge by:
- expanding the surface area of the composting plant’s hot phase;
- relocating the compost maturation area;
- safeguarding sludge management with an alternative installation for sludge liming;
- supplementing the necessary technical equipment – a loader and a compost screen.
- To enable the efficient utilization of increased biogas production by:
- increasing the capacity of the biogas holder;
- executing the necessary adaptation of the power system and the I&C (Instrumentation and Control) system.
Primary Objectives of the Project:
- OBJECTIVE 1: Capacity to receive new loads at the treatment plant by an additional 15–20 thousand PE. The achievement of this objective will eliminate the deficiencies of the existing wastewater treatment process and create the capacity to receive additional pollutant loads in the incoming wastewater.
- OBJECTIVE 2: Increasing the throughput of the sludge unit and improving sludge stabilization conditions by constructing another anaerobic digestion tank (ZKF) with a capacity of 2,500 m³.
- OBJECTIVE 3: Reducing odor nuisance. The implementation of the project is intended to solve odor nuisance issues and the shortcomings of the existing technological solutions.
- OBJECTIVE 4: Improving energy efficiency and raising the level of energy self-sufficiency to above 80% of the total electricity demand. Increasing the storage capacity for biogas will result in a more efficient load on the CHP unit, reduce system failure rates, and improve the utilization of available capacity, along with the smart control of motor power supplies.
- OBJECTIVE 5: Modernization of sanitary sewerage systems. The planned activities related to the construction of the sewerage network in Chełmońskiego Street in Słupsk and the discharge pipeline from Kobylnica to the sewerage network in Grottgera Street in Słupsk are intended to solve sewerage network problems.
- Additionally, the construction of a transit sanitary sewerage network (“Słupsk Sewerage Ring”) and the expansion of the wastewater pumping station at Borchardta Street along with a discharge pipeline to the wastewater treatment plant are foreseen. The implementation of this investment will contribute to increasing the safety and operational reliability of the sewerage system within the agglomeration.
The realization of individual primary objectives will yield synergistic effects, the impact of which may extend to a larger scale, rather than merely addressing the elimination of facility deficiencies:
- environmental objective: ensuring a good state of the environment through the proper processing of sewage sludge and other waste generated both at the Słupsk treatment plant and outside it, increasing the utilization of the energy potential of sludge and biodegradable waste, thereby reducing greenhouse gas emissions;
- health objective: reducing pathogenic risks when applying sludge and/or compost in agriculture through the use of advanced stabilization and hygienization processes; additionally, reducing the ambient emissions of the entire treatment plant facility;
- technical and organizational objective: increasing the capacity to receive a larger volume of loads in wastewater, streamlining sludge management at the treatment plant, and improving management efficiency;
- formal and legal objective: meeting the requirements of Polish law and European Union legislation, in accordance with the priorities prevailing in water, wastewater, and waste management (e.g., the waste hierarchy, RES, etc.);
- economic objective: influencing the development of the local economy, increasing the attractiveness of the area for investors, and promoting the tourism potential of the region;
- social objective: raising the standard of living for residents and gaining acceptance for regional initiatives.
Project Scope
The project foresees, among other things, the following activities:
a/ in the sludge section:
- construction of a fourth anaerobic digestion tank – additional digestion volume – ZKF with a capacity of 2,500 m³ along with the necessary technological equipment, in particular a low-speed mixer, and the reconstruction of the Digestion Tank Machinery Room along with the necessary technological equipment;
- construction of a biogas holder with a capacity of 1,250 m³;
- construction of a biological reactor for reject water [SBR], encompassing:
- Facility – ZON – Unpasteurized Sludge Tank
- Facility – ZOB – Dirty Reject Water Tank
- Facility – RBO – Biological Reactor for Reject Water
- Facility – POB – Sludge and Dirty Reject Water Pumping Station
- Facility – SOR – Reactor Operating Station
- Facility – BF.2 – Biofiltration Installation and Biofilter for facility deodorization at the wastewater treatment plant
- reconstruction of the power system and I&C (Instrumentation and Control) encompassing the adaptation of existing facilities for expansion needs, along with the necessary technological equipment;
- construction of an installation for liming dewatered sludge, encompassing the delivery and assembly of equipment for the sludge liming installation, along with the reconstruction of the installation transporting sludge from the centrifuge to the limed sludge storage facility, and the delivery and assembly of a thickening centrifuge;
- construction of the composting plant biofiltration installation, encompassing:
- execution and assembly of a partial enclosure for the composting plant shelter with roller shutter doors,
- execution and assembly of the under-roof and under-pile ventilation installation and a biofilter for the composting plant along with the necessary technological equipment, and modification of the ventilation system layout related to the existing supply fans to enable the reversible operation of these fans;
- expanding the surface area of the composting plant’s hot phase;
- relocating the compost maturation area;
- supplementing technical equipment – purchase with delivery of: a screen (a drum screen with an electrically driven motor) and a loader with a bucket capacity of up to 2.8 m³ with additional attachments, including a straw grabber.
b/ in the sewerage section:
- modernization of the sewerage system through:
- the construction of a new sewerage network in Chełmońskiego Street and a transmission system from Kobylnica to Słupsk.
- As part of the modernization of the existing municipal wastewater collection and discharge system in Chełmońskiego Street in Słupsk, the construction of approx. 200 meters of a sanitary sewerage network is planned.
- As part of the modernization of the transmission system from Kobylnica along Kolejowa and Kilińskiego Streets to Grottgera Street in Słupsk, the project foresees the construction of approx. 661 meters of a discharge main, a section of a gravity pipeline of approx. 9 meters, and fittings: a gate valve chamber and a metering chamber.
- The function of this sewerage system is to discharge domestic wastewater from the area of Kobylnica through a tight transit pipeline to the Słupsk wastewater treatment plant via the Słupsk city sewerage catchment area.
- construction of a transit sanitary sewerage network – “Słupsk Sewerage Ring”
- The task includes the construction of a transit sanitary sewerage network from the locality of Głobino to the wastewater treatment plant in Słupsk. The investment is necessary to relieve the existing sewerage system in the center of the City of Słupsk and to discharge wastewater from the area of the Słupsk Municipality and the adjacent areas of the city directly to the treatment plant. The expected total length of the pipelines for the constructed sanitary sewerage network is 15,475 meters.
- expansion of the wastewater pumping station at Borchardta Street along with a discharge pipeline to the wastewater treatment plant
- Within the framework of the task, the construction of a sanitary sewerage network with a length of approx. 650 meters is foreseen. The investment is implemented to increase the capacity of the discharge system to the treatment plant, the capacity of which is insufficient during periods of increased wastewater inflows.
The modernization of the sanitary sewerage network system will reduce the risk of flooding and will increase the throughput and transport safety of wastewater within the local sanitary sewerage systems.
c/ construction of a Septic Tank Truck Emptying Station (SOWA)
The construction of a station for emptying and washing septic tank trucks, along with the proper separation of waste generated during sewer network cleaning in the form of screenings and sand, is necessary to improve the operation of the wastewater reception point and its treatment during the mechanical wastewater treatment phase in the grit chamber.
- Implementation period: April 2014 – December 2015