In early summer, it was decided that the equipment for the world’s most advanced wastewater treatment plant, Sickla treatment plant, would be provided by Borås-based company Hydria Water. Hydria Water is part of the family-owned Borås corporation, Hydria Group. The order’s value amounts to approximately 60 million SEK and marks the single largest order in the company’s history.

– This is both a significant and unique order for an incredibly exciting and extensive project. I am proud that our company the Hydria Group have the opportunity to be part of this, says Tobias Barrstrand, CEO of Hydria Water and Hydria Group.

Sickla wastewater treatment plant is being constructed beneath Hammarbybacken in Skarpnäck, just outside Stockholm. A total of 530,000 cubic meters of solid rock will be excavated from under the hill, which is equivalent to the volume of Avicii Arena. Simultaneously, Henriksdals wastewater treatment plant is being expanded and upgraded to become one of the world’s most advanced treatment plants.

The Sickla facility is part of the Stockholm Future Wastewater project. The expansions are being carried out not only to increase capacity but also to meet stricter requirements, including those related to emissions into the Baltic Sea.

– This project is unique for us because of its size and scope, the largest in Hydria Water’s history. We hope to further strengthen our position in the industry with this project and we look forward to doing so in collaboration with Veidekke/Veitech. Within our segment and the market we operate in, this project is something truly unique, says Johan Fritz Sales Manager at Hydria Water.

Hydria Water’s equipment will be present in most of the process stages in the treatment plant. This encompasses more than 70 unique machine installations with additional components that will be delivered to 20 sedimentation basins, each measuring 70 meters in length, 8 meters in width, and 5 meters in depth.

– Now, we look forward to planning the installations, which will be carried out in collaboration with Hydria Water’s own personnel. Eventually, we also anticipate the equipment deliveries and their installation. It is reassuring to have Hydria Water by our side until the plant’s commissioning, says Kristofer Eklund, Project Manager at Veitec.

A Market-Leading and Reliable Supplier

Hydria Water won the contract due to both trust in Hydria Water as a company and its market-leading position. Hydria Water is already represented in most wastewater treatment plants in Sweden.

– We are the only Swedish manufacturer with our own solution for plastic chain scrapers, where we own all development and manufacturing. It is particularly satisfying to receive this contract considering the tough competition from several foreign competitors. The fact that we are perceived as a reliable supplier contributed to the decision, säger Johan Fritz, Sales Manager at Hydria Water.

The evaluation of the submitted bids was conducted by Veitech in collaboration with Stockholm Water.

– After this process, Hydria Water was considered to have the best technical and commercial proposal for all the scraping systems for the Sickla project, says Kristofer Eklund, Veitech.

With the delivery in place, Hydria Water will have approximately 100 scraper systems in three of Stockholm’s largest wastewater treatment plants.

– What makes this project particularly exciting is, of course, its scale. At the same time, we have been leading the development of equipment for sedimentation basins for many years, and these are machines that we are extremely confident in delivering, says Tobias Barrstrand, CEO of Hydria Water and the Hydria Group

Equipment deliveries are scheduled to begin in the first quarter of 2024, with the project expected to be completed by 2026.

Here’s what Hydria Water will deliver:

Equipment for 20 sedimentation basins, each measuring 70 meters in length, 8 meters in width, and 5 meters in depth.

• 20 plastic chain scrapers for primary sedimentation basins
• 20 circular sludge scrapers
• 20 decanting throughs
• 50 skimmer boxes
• 6 plastic chain scrapers for sand traps
• 24 skimmer boxes for sand traps
• Assembly of all equipment

Read the full press release in Swedish here.

In October 2022, Hydria Water conducted an inspection of pre-sedimentation sludge scrapers at the Källby wastewater treatment plant located near Lund. The results indicated that it was time to replace both the scrapers and chains, as well as the idler sprockets in all tanks.

The project began at the end of February and was completed less than four months later.

– In total, there were 12 tanks that were divided into pairs, Eric Folebäck, maintenance manager from VA Syd, explains. The project was carried out by shutting down one pair of basins at a time, with a week-long period for flushing and cleaning, followed by a week of dismantling and installation performed by Hydria Water.

The initial plan was to finish the project within 12 weeks, but heavy rainfall and sub-zero temperatures caused challenges, making it difficult to keep the basins emptied and safe to work in.

– Still, I feel that the work proceeded smoothly, and it was easy to stay in touch with Hydria Water’s representatives throughout the process. The replacement parts also came from Hydria, and the fact that there were drawings available from previous work on the tanks proved to be very helpful, Eric says.

The proposal from the European Commission for a new wastewater directive outlines tougher and more demands for wastewater treatment. As a step towards meeting these new directives, Hydria Water was hired to strengthen the treatment done at a wastewater treatment plant in the Icelandic town of Keflavik.  

– Instead of going through a costly refurbishment and building concrete basins, they chose to go with an above-ground concept and install two of our Combi Units. This will not only be more cost-effective but also be much more energy-efficient, says Andreas Riedel, CTO at Hydria Water.  

In this project, Hydria Water has also supported the piping design and tailored a distribution box to reduce the need for additional pumps and valves. Furthermore, they have prepared for a future installation of a third Combi Unit and developed a remote monitoring system.  

– This system enables the customer to optimise remotely via Netbiter and will have direct access to vibration monitor, level gauge and measuring of dry substance content etc, Andreas explains.  

Towards the end of August, the machines are supposed to be up and running, and Hydria Water will be on hand in Keflavik to support the start-up and commissioning.    

Öresundsverket recently hired Hydria Water to refurbish two of their primary sedimentation basins. With the help of our online energy-saving tool, the customer could easily calculate that refurbishment had resulted in 67% improved energy efficiency and had reduced their emissions by 169 kg CO²/year.

“The primary reason for the change was old age, and we needed to ensure the scraper system ran smoothly as the rubber scrapers were more or less worn down. The advantage of these new scrapers is that we are rid of the wheels, and it is easier and less costly to just change the skids”, says Andreas Fäldt, Operations Engineer at Öresundsverket.

Öresundsverket is one of Sweden’s largest wastewater treatment plants, which runs solely on biological phosphorus removal. Approximately 138,000 person equivalents and several larger and smaller factories are connected to the wastewater treatment plant, which receives an average of 55,000m3 water per day.

Photo: NSVA, Timo Julko 

It was only ever meant to be a short interlude for Andreas Riedel when Hydria Water needed a welder to help out on a big project involving sending distributors to Managua in Nicaragua. 17 years later, he is CTO and the second generation of his family working at the company.  

“I was quickly onboarded and went on to construction. After a few years, I had the privilege of building this department from scratch when the company underwent restructuring. I managed the recruitment, and my focus was to transform this into an efficient department with agility and technical expertise”, says Andreas.

Andreas’s dad also worked in construction and as the Head of Technology during his many years at Hydria Water. They share an interest in technology, mathematics and innovation.  

“Working with innovation that serves society as a whole feels amazing. At Hydria Water, we are not afraid of thinking outside the box and finding new solutions that differ from our competitors’.”

Andreas personally feels it is the combination of the environmental issue and the technical challenge that spurs him on in his everyday work, as well as having the opportunity to manage his own projects and push topics that are close to his heart.  

“Right now, we are getting prepared for an AI project that can benefit our customers greatly as the machine will be able to update itself in the future. I hope, and firmly believe, that we will have a complete beta version within a year or so.”

Hydria Water is owned by the Swedish family corporation Hydria Group which, as far as Andreas is concerned, is a great advantage.  

“To be part of Hydria Group is an advantage which makes it easier to work long-term instead of constantly keeping an eye on the quarterly report.”

This summer, Andreas’s daughters will work at Hydria Water as part of a digitisation project. They will then be the third generation from the same family at this company.

After a year of developmental work and two years of field-testing, the Wash Press Gamma WPG is being launched; a one-of-a-kind solution for compressing and dewatering screenings.

“By questioning established techniques and methods currently available on the market, our driving force has been to embrace new perspectives and develop a solution that reduces wear and tear maintenance, as well as almost doubling the amount of dry solids content”, says Andreas Riedel, CTO at Hydria Water.

Some of the competitors’ products involve technology where an impeller is used that fragments the contamination and separates it from rags and screenings. But, according to Andreas, the problem with this method is that the screening is handled too harshly, which in turn leads to a higher ratio of waste particles in the wastewater from the processing phase.

“The existing technology is also risking more wear and tear, and potential breakdown as this involves fast-moving parts in a highly contaminated media.”

A patented, one-of-a-kind solution

Our technology is all about adding compressed air that penetrates the drainage perforation and separates organic contamination or such like from the mass without fragmenting the rags, which instead can be compressed in any way you wish. Furthermore, the product keeps the perforation clean and is self-cleaning; thus, no brushes are required, as is common in many other solutions.

“The machine receives separated screenings from the previous process. After which service water or technical water are added, and then a wash cycle starts with the help of the patented compressed-air function. After a completed wash cycle, the wastewater valve opens, the screw starts and the compression phase is initiated. We believe many will be curious about this new product and that we can find more customers who can see the benefits based on their perspectives and specific markets.”

Tried and tested at a wastewater treatment plant

To ensure the functionality of the Wash Press Gamma WPG, it has been tested in the operation of a wastewater treatment plant over a two-year period with careful monitoring.

“It has run without any issues and we can achieve 60 per cent dry substance content, compared to approximately 35 percent with conventional technology.”

Facts about our Wash Press Gamma WPG

• Keeps the drainage perforation clean without the need for brushes.
• Hardox-reinforced screw in the compression zone will provide up to 25 per cent longer lifespan without reducing capacity.
• Optional grease removal in the application if there is no possibility of handling grease in subsequent process phases.
• The aerosol trap is standard to protect the ventilation system from excessive moisture and dirt.