Sewage treatment in Gaarkeuken 3.8 million euros more expensive – News

through sustainability and indexation

The Noorderzijlvest Water Board is allocating 857,000 euros to make the new sewage treatment plant in Gaarkeuken more sustainable. The general council has agreed to install a tire thickener and a pressure sewer. In addition, it has approved an additional credit of more than 3 million euros for additional indexation costs.

The construction of the sewage treatment plant is already in full swing. In addition to the new purification, the water board is realizing a wastewater transport system, consisting of approximately 20 kilometers of pressure pipes and sewage pumping stations (new construction and renovation). The total costs of the Westerkwartier sewage treatment plant project, including the extra credit, now amount to 66.9 million euros.

The work has been awarded to ADS Groep Water (wastewater treatment plant) and Strukton (pressure pipes and pumping stations), respectively. The new WWTP will be completed in 2025. It is the merger of the existing and outdated treatment locations of Marum, Zuidhorn and Gaarkeuken. The locations in Marum and Zuidhorn will be demolished.

The new treatment plant will be realized with ‘the best available techniques’, but as part of the tender procedure the water board also asked the market to come up with ‘sustainability proposals’. ADS Group Water developed 5, 2 of which have now been given the green light by the general board: a tire thickener and the construction of a pressure sewer.

The belt thickener ensures a lower sludge volume of the secondary sludge, and therefore also lower transport costs. In addition, the design of the purification can be ‘optimized’ by using the belt thickener, resulting in less sludge being released. This has a positive effect on the operation of the WWTP, which is calculated by the water board at 175,000 euros annually. Less sludge also means fewer sludge transports, which is good for the CO2 footprint of the WWTP and for local residents because fewer trucks means less inconvenience.

The construction of the pressure sewer is at the request of local residents. They want to be disconnected from their IBAs (Individual Wastewater Treatment) and connected to the Soup Kitchen sewage treatment plant. To meet this wish, they must be connected via a pressure pipe and sewage pumping station. This application increases support for the new sewage treatment plant, writes the water board, which will bear the costs for the construction of the pressure sewer, although this is in fact a core task of the municipality of Westerkwartier. It does agree to accelerated depreciation of the IBAs and is responsible for the management and maintenance of three sewage pumping stations.

Of the five sustainability proposals, cellulose recovery, intelligent process control and a digital management system (digital twin) did not reach the finish line. The board does not like the process of cellulose recovery because it increases operational risks. Intelligent process control would reduce the information security level of the water board’s sewage treatment plants and the water board is not yet ready for the implementation of digital twin. “The system can also be purchased afterwards,” states the proposal for additional credit that received approval from the general board last week.

source: h20water network