Client:   Prefectural Self-Government Of Cyclades
Year:     1997
Budget: 2.212.000€ (value in 1998)

ISSUE
The purpose of the project was the final design of the following:

• sewer pipeline network in the Community of Koufonisia
• force main sewer pipelines for the transfer of collected wastewater from the community of Koufonisia to the new Wastewater Treatment Plant (WWTP)
• new WWTP for the Municipality, within an area of 0.4 hectares located at a short distance from the sea

SOLUTION
The Community of Koufonisia was served by septic tanks, with produced wastewater being discharged untreated in the broader region resulting in the degradation of the natural environment and the quality of life for local residents.
 
The table below presents total peak population of the examined community through each design phase. 

The design of the project prepared in accordance with the Greek Presidential Decree 696/74. The design of pipelines, pumping stations and WWTP, was based on a 40-year horizon, while the selection of electrical and mechanical equipment was based on a 20-year horizon. More specifically, the project included:

• internal gravity sewer network in the community of Koufonisia (with a total length of 5.590m and pipeline diameters ranging from 90mm to 315mm) It is mentioned that for adequate wastewater collection, additional force main pipelines were designed (with a total length of 1.750m and pipeline diameters ranging from 90mm to 315mm), while three (3) internal pumping stations were designed for pumping wastewater
• external force main pipeline network (with a total length of 1.200m and pipeline diameters of 160mm)
• WWTP which treats incoming wastewater adopting the treatment process of activated sludge with extended aeration (design population equivalent (PE) 20 years: 3.000 residents); treated effluent is discharged via an underwater pipeline to the sea. In summary, the WWTP consists of the following units:
• septage reception unit
• influent manhole 
• bar screens
• sand and grit removal
• automations M&E
• flow measurement 
• sedimentation tanks 
• pumping stations
• instrumentation, mechanical & electrical equipment
• access road to the WWTP (dirt road with a length of 520m)
• fencing - landscaping
  

BENEFIT
The design of the sewer pipelines and the WWTP resolved the wastewater collection and treatment for the community of Koufonisia.