Berlin, 10.05.2021 – WABA, Altenburg’s water works company, awarded the contract to PORR’s civil engineering department in Berlin on 20 April 2021. The 15 million euro investment will upgrade and refit the central sewage treatment plant in the town in Thuringia, Germany. Once the renovations are complete, the town’s sewage sludge will no longer be mere effluent: a combined heat and power plant (CHP) will spin it into gold – or rather, heat and electricity.
The contract is for turnkey completion of the work – from foundations to operation. PORR teams will take on the specialist civil engineering work involved in the foundations for the new tanks and buildings, earthworks and landscaping, concrete construction, finishing and equipping the plant with machinery, and commissioning the new systems. PORR’s sister company pde Integrale Planung GmbH will handle the technical project management involved in planning the work.
The upgrades, which will be carried out while the plant continues to operate, consist of addition of a primary settlement tank and two sludge digesters with gas treatment systems and gas tanks. A new machine house is also to be built complete with pump systems, a centrifugal sludge dewatering system and three CHPs to generate heat and electricity from the digester gas. To keep the existing plant operating as work progresses, all wastewater entering the system through the structural connection to the new primary settlement tank will be diverted directly from the sand trap to the aeration tanks via a temporary siphon system.
Spinning sludge into gold: generating heat and electricity
The two 2,100m³ digesters will be welded together on the construction site from solid steel plates. These digesters, operating at 35-37°C use mesophilic microorganisms and bacteria to “digest” the sewage sludge – or, to use the technical term, for anaerobic stabilisation. The process releases gas known as digester gas, which is then transformed into energy. To complete the loop, this energy will be used to supply the systems, making the sewage treatment plant almost self-sufficient. This represents a big step forward for a sustainable future: the plant will not only purify wastewater, but its new CHPs will generate green electricity and local and district heating.
Safe, sustainable and shoulder-to-shoulder to meet an ambitious schedule
The PORR team will not wave goodbye to the project as soon construction work is complete: PORR experts will be involved with the commissioning and trial operation of the new plant, which will then be handed over to the client with all its new systems up and running. The project schedule is ambitious – the handover is planned to take place in just 18 months. Excavators moved in almost immediately after contract award and by 3 May the earthworks were underway.
Facts and figures at a glance:
| Project type: | civil engineering |
| Scope of services: | renovation of Altenburg’s central sewage treatment plant |
| Client: | Wasservorsorgungs- und Abwasserentsorgungsbetrieb Altenburg (WABA) |
| Contractor: | PORR GmbH & Co. KGaA |
Order volume: | EUR 14,8 Mio. gross |
| Construction start: | May 2021 |
| Completion: | 2022 |
For enquiries, please contact:
Udo Pauly
Head of Corporate Communications
PORR GmbH & Co. KGaA
T +49 89 71001 213
presse@porr.de
