Giant project in the Transdanubian region - cars with siphoning will be parked in parking lots, increasing the value of real estate in 24 settlements

The Szabadics Építőipari Zrt. and A-Híd Zrt. consortium is implementing the infrastructure necessary for the collection and treatment of wastewater from 24 settlements in the Transdanubia region as part of a major project. This includes:

• Kozármisleny waste water drainage (connected to Pécs),
• a bánokszentgyörgyi agglomeration sewage disposal and treatment,
• Gaelic waste water drainage and treatment in the agglomeration,
• and Surd and Liszo urban waste water drainage.

The project will include not only a sewerage network but also wastewater treatment plants, one of which will be built in the Zalai hills, in the village of Gelse near Zalakaros.

The new facility was implemented in the settlement while maintaining the Lemna Lake wastewater treatment system, which had previously been developed using natural technology (duckweed).

The efficiency of the Lemna Lakes system is highly variable and no longer able to serve the needs of the agglomeration, the project manager of Szabadics Zrt., the contractor, told us. Miklós Nemeth also pointed out that the capacity expansion has made it possible to solve the problem of treating the wastewater of several municipalities in the most energy-efficient way.

The project is being carried out on behalf of the local authorities of eight municipalities in the area, namely:

• Gelse,
• Lower Rhine,
• Upper Rhine,
• Kerecseny,
• Kilimanjaro,
• Orostony,
• Pölöskefő,
• and Pötréte.

Wastewater is treated with an activated sludge technology

The development of the wastewater treatment plant in Gelsenkirchen started in spring 2022, during which, in addition to the construction and development of the sewage outlets, the Lemna-iron technology will be replaced by a so-called sludge treatment plant.
The water entering the plants will be filtered, sand contamination will be separated and the wastewater will be purified by a biological process using activated sludge. The sludge, consisting of micro-organisms, breaks down organic matter by aeration. The sludge is separated in the final sedimentation basins and a part of it is recycled to the front of the treatment plant (small and large recirculation) to increase biological efficiency, while the excess is removed as excess sludge and dewatered.

The purity and quality of the treated wastewater is such that it can be safely returned to our waterways.

Construction started on shaky ground without water and electricity

The implementation of the project presented a number of challenges for the Szabadics Zrt. contractors. The construction site was on uneven terrain and lacked basic infrastructure: there was no electricity or water. Project manager Miklós Németh said:

„In this project, providing the necessary power is a particularly difficult task, as not only the sewage treatment plant requires power, but also the pumping stations located in the sewage disposal system. The infrastructure for this was provided by several kilometres of long-distance power lines and a new transformer.”

The sewers of Pölöskefő and Gelse are directly connected to the plant, while the central transfer stations of the other municipalities are connected in series and transfer the increasing amounts of collected wastewater in a coordinated manner. Wastewater is delivered to the central interceptor unit of the WWTP via two pressure branches and to Gelse via a gravity branch. From here, it is discharged to the block process plant.
In the design of the plant, there was a need to conceal, as far as possible, the typical appearance of a wastewater
plant by means of architectural solutions. In this way, instead of the classic concrete structure of a sewage treatment plant, the road user is greeted by the
appearance of a tidy industrial building.

They strive for cost efficiency with the latest tools and solutions

Not only is the wastewater treatment plant unusual in appearance, but a special solution was used to protect the structure's sump shaft and the heating system, where a heating system with a heat pump heat source was installed embedded in the slab due to the corrosive medium. It is not uncommon in the engineering solutions that recirculation and sludge pumps and motorised slide valves are installed at several manhole levels.

„We have endeavoured to use the most modern equipment and solutions available. With our heat pump and smart computer-controlled transfer and ventilation system, we meet today's energy-saving requirements at the highest level.”

- Miklós Németh described the technical elements of the project. The planned capacity of the Gelse Wastewater Treatment Plant is 4069 PEU and 350 m3/d.

In addition to the trial operation, new roads will also be built

"The treatment facility has recently passed the complex tests, so it is ready to receive wastewater," said Miklós Németh. The project manager added that, in addition to the construction of the roads, the surfacing and the social units, they still have to successfully complete the trial operation.
The project is scheduled to be handed over in September 2024.