Improvements are being made to the municipal waste water collection and treatment, and water supply infrastructure in Rijeka – Croatia’s third-largest city with a population of approximately 190 000 – under an EU-funded project due to be completed in late 2023. The objectives of the project are to increase connection rates to the public sewerage system, provide for adequate levels of waste water treatment and reduce water losses from the supply network.
- 22 March 2019
The project covers work on almost 220 km of sewerage infrastructure, of which around 30 km are to be rebuilt and the rest laid from scratch. This extended network will include 126 pumping stations and 25 km of high-pressure pipes for discharge of water. A total of 2 512 small pumping stations are being installed to connect additional users to the sewerage pipelines.
Twelve retention basins for management of storm water runoff, 20 storm water overflows for controlled discharge of storm water and three separators for separation of waste water from other substances are under construction.
Cutting losses
Rijeka’s water supply and waste water collection system is considered to be one of the most complex in Croatia. Although the city is well-served by its water-supply network – with a connection rate of 99.8 % – the infrastructure is ageing and investments in upgrades are necessary to reduce water losses from the system.
A further element of the project thus involves replacing water supply pipelines totalling 99.53 km in length, which should reduce water losses from their current level of about 30 % to 23 %.
At present, the waste water collection network is much less extensive than the water supply network. The connection rate to the sewerage system is 78.33 %. As a result of the extensions, this is expected to rise to 93.79 %, representing important progress towards the attainment of EU and national waste water service coverage targets.
Improved waste water treatment
To increase the efficiency of waste water treatment in Rijeka, a new treatment plant is to be built on the site of an existing plant, which will be demolished. The existing facility only provides for primary (or mechanical) treatment, which involves the removal of fine solids from the water by settlement in a sedimentation tank. It therefore does not meet the waste water treatment requirements laid down in EU legislation.
The new treatment plant will have the capacity to perform secondary (or biological) treatment of volumes of waste water equivalent to those that would normally be produced by 200 000 people. This process uses oxygen to biodegrade dissolved and suspended organic matter in waste water. This is essential to ensure the waste is treated to an adequate level prior to discharge into the environment. Thermal drying of sludge will be carried out at the new plant.
Total investment and EU funding
Total investment for the project “Improvement of the water communal infrastructure - Rijeka Agglomeration” is EUR 289 730 832, with the EU’s Cohesion Fund contributing EUR 165 335 326 through the “Competitiveness and Cohesion” Operational Programme for the 2014-2020 programming period.