WWTP upgrading: Construction of the phosphorus polishing station comprising of the pumping station, phosphorus precipitation plant and state-of-the-art rotating disc filters has been completed. The test operation has started on 15 September 2021. Bulk flow meters were installed which allow establishing a precise water balance and phosphorus balance of the WWTP. The sludge dewatering facilities were generally overhauled and a canopy was built over the sludge loading area to avoid rain diluting the dewatered sludge. A hook loader truck and containers were procured so that PUC can transport the dewatered sludge to the regional landfill, where it is used for producing compost. An emergency response plan has been developed to enable PUC to react quickly in case of an emergency at the WWTP in order to minimise potential phosphorus spills to Lake Palic. Through all these measures the phosphorus discharge to Lake Palic will be significantly reduced.
Palic WWPS: construction of the wastewater pumping station was completed. Since the beginning of August, the WW of Palic is pumped to the Subotica WWTP and treated there. Special water hammer equipment was installed to protect the 5 km long pumping main from hydraulic damages. The pumping station was taken over by PUC on 15 September 2021. Optimization of the plant and finalising outstanding activities continues.
Palic sewerage: the construction of an 18.6 km sewer network was originally planned; 21.9 km were actually constructed and works were completed in October 2020.
Construction of buffer zones: Construction works for the buffer zones (green belt) around Lake Palic and Lake Ludas are completed to approx. 85% and works are scheduled to be completed in November 2021. A long period is required, since planting trees and bushes is only possible in spring and autumn. Watering of the trees and bushes and cutting of grass and invasive plant species is ongoing. Machines and equipment (tractor, multi-purpose machine, trailer, mowing machines etc.) has been procured for maintaining the buffer zone, and PE Palic-Ludas is intensively using it. Construction of bird watchtowers and rest areas was completed in September 2021 and the facilities are well accepted by visitors. The construction of foot paths and bicycle lanes has been completed in June 2021. 2214 meters were originally planned and 2690 meters have actually been constructed. Right from the date of completion, the facilities have been intensively used by the local population and by visitors.
Biomanipulation: A specialised fishery boat, 8 trap nets and other fishery equipment were procured and are now used by PE Palic-Ludas for selective fishing. Selective fishing campaigns were performed in 2019, 2020, 2021 and will continue in future, as it is necessary to control the population of the Prussian Carp (Babuska). The 2021 campaign was re-started on 2 September and the amount of landed is very satisfactory. This fish species is not native in the region and reproduces massively if not continuously controlled by selective fishing; an overpopulation of the fish would negatively affect the water quality. As part of the project, scientific research was done by the Scientific Institute of Veterinary Medicine of Serbia, led by Dr Vladimir Radosavljevic. It was possible to clearly prove that the seasonal fish kill of the Prussian carp is caused by an outbreak of the herpesvirus hematopoietic necrosis (HVHN) and is not related to the water quality. The virus affects only the Prussian carp, not the other fish species in the lake and is not harmful to human beings.
Due to the long turn-over period of the lake body, the positive effects of all the above measures on the water quality of Lake Palic will be fully visible and measurable only about 8 months after the facilities are in operation. Therefore, the lake monitoring will be continued till the end of 2022.
The investment period of the project has been extended till November 2021 due to COVID restriction measures.