
Project facts
3,952 m³/day
Capacity
- Main contractor
- JV THALIS E.S. – MESOGEIOS S.A.
- Project owner
- Chalkidona Municipal Water & Sewerage Company
- Location
- Chalkidona & Adendro, Thessaloniki
- Project type
- Wastewater treatment plant
- Completion
- 2018
- Funding
- EU — ESPA / YMEPERAA
- Our role
- Structural works subcontractor
- Rising mains
- 400 m & twin 768 m
- Village pumping stations
- A4 · A6 · AK
01 — The challenge
In a wastewater treatment plant, concrete is not judged on strength alone. The tanks have to stay watertight and withstand permanent contact with sewage, and their tolerances are set not by the contractor but by the equipment that will sit on them — a scraper bridge forgives nothing. The programme was not ours either: we worked as structural subcontractor inside the main contractor’s schedule, with the process and M&E crews waiting on each structure in turn.
02 — Our solution
We organised the structural work by structure rather than by trade, so each tank was handed over complete and released immediately for its equipment. The circular tanks were reinforced and poured in continuous phases, the rectangular walls formed with steel formwork that gives a repeatable finish, and in parallel we built the service buildings, the village pumping stations and the rising mains — so the plant would not sit waiting for the network that feeds it.
Photography
Construction stages
10 photos
Technical scope
14 trades,
one contractor
- 01Earthworks & excavation
- 02Wastewater pre-treatment tank
- 03Circular reinforced concrete tanks
- 04Rectangular tanks & channels
- 05Watertight concrete for liquid-retaining structures
- 06Return & surplus sludge pumping station
- 07Sludge storage tank
- 08Equipment bases & starter bars
- 09Service buildings
- 10Village pumping stations A4 · A6 · AK
- 11400 m rising mains
- 12Twin 768 m rising main
- 13Site services networks
- 14Internal roads & site works

The outcome
The plant has been in operation since 2018, serving Chalkidona and Adendro with a capacity of 3,952 m³ of wastewater per day. Alongside the plant we built the village pumping stations A4, A6 and AK and the rising mains — 400 metres plus a twin 768-metre main — that connect it to the network. The project was financed by the EU through the Greek Operational Programme for Transport Infrastructure, Environment and Sustainable Development.
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