Construction Company


Address : 10 Germanikis Sholis Athinon str. (Ex Ziridi), Gr 15123 Marousi, Athens, Greece
Tel : +30 210.6100500
Fax : +30 210.6857094
E-mail :

Environmental Projects


3. Sewage and Septics Treatment Plant for Thessaloniki Touristic Area

Thessaloniki Touristic Area Sewage Treatment Plant serves the treatment of the sewge of the East Thermaikos Coastal Areas (Perea, Agia Triada, Michaniona, Epanomi, etc.) with a population equivalent of 150.000.

It includes preliminary septics treatment (mechanical screening, balancing, degritting, pumping), preliminary sewage treatment (mechanical screening, flow measurement, degritting, grease removal), two biological reactors, for the removal of organic carbon and nitrogen of 5.500 m3 each, two primary clarification tanks (25 m diameter), two final sentimentation tanks (31,5 m diameter), disinfection system including two ozone production units, and a contact tank of 920 m3 volume, two sludge thickeners, two anaerobic digesters, one post thickener, a sludge dewatering plant and an electrical and heat biogas generation plant for a 250 KVA electricalcapacity.


4. Sewage and Septic Waste Treatment Plant for Chalkis city

The SEWAGE TREATMENT PLANT AT CHALKIS was executed in 2 stages.

The first stage (I) of the works included design, construction and operation of the installation for three years, with the objective to provide full treatment for 2.000m3/day of sewage and 600m3/day of septic waste, and serving a population equivalent of approximately 20.000 e.p.

The main works of stage I were:
- Septic waste reception unit, preliminary treatment and pumping.
- Preliminary sewage treatment unit.
- A Primary Clarification Tank 16m diameter.
- Aeration basin of 1.200m3 volume.
- Final Sedimentation Tank 22m diameter.
- Chlorination Unit.
- Sludge Thickener 10m diameter.
- Anaerobic Digester 900m3 volume.
- Second stage Digester.
- Sludge Dewatering system.
- Biogas storage tank of 200m3 volume.
- Digesters heating and mixing unit.
- Various pumping units.
- Three HDPE submarine pipelines for the transfer of sewage and septic wastes (diameter 315mm, each 550m in length approx.).
- Sea outfalls for disposal of treated sewage, HDPE diameter 315mm, 300m in length approx.

The second stage (II) of the works was carried out in parallel to the operation of the existing plant with the objective to increase the treatment potential to 9500 m3/day of municipal sewage and to 1.600m3/day of septic wastes, thus serving a population of 61.000 e.p. Furthermore, the treatment process was upgraded to remove nutrients (nitrogen and phosphorous), in accordance with the new requirements for the protection of waters at Euvoikos bay.

The main works in stage II are:
- Balancing tank of sewage of 2.500m3 volume.
- Balancing tank of septic wastes of 870m3 volume.
- Air feeding system for stirring of the material of the above tank.
- New Primary Clarification tank of 16m diameter and total volume of 600m3.
- Two (2) tanks of 200m3 volume each for the biological phosphorus removal.
- New Nitrification / Denitrification tank of 1.800m3 volume.
- Modification of the existing Aeration Tank of 1.200m3 volume to a Nitrification /
- Denitrification tank of 1.800m3 volume.
- Aluminium Sulphate dosing unit for the removal of phosphorous.
- New Final Sedimentation Tank of 22m diameter and volume 1.200m3.
- New Sludge Thickener of 10m diameter and volume 250m3.