Client:  Municipal Water Wastewater Utility of Serres
Year:    2001

ISSUE
The purpose of the project was the renewal – alteration of the Environmental Permit with respect to the expansion of the existing WWTP of Municipality of Serres. The WWTP is located 3km south of the city of Serres.

SOLUTION                                                                                                         WWTP View
The construction of the sewerage network in the city of Serres and the integration of new Municipal Districts to Serres Municipality in conjunction with the decision of the adjacent Municipalities of Skoutari, Lefkona and Mitrousi to transfer their wastewater to the existing WWTP of Serres, resulted in an increase to the population equivalent from 88.000 to 105.000 for the year 2015.
The WWTP was designed to treat incoming untreated wastewater adopting the treatment process of activated sludge with extended aeration and includes the following modules and subsystems:

• influent manhole
• bar screens 
• initial elevation pumping station
• sand, grit and grease removal
• flow measurement
• oxidation – nitrification – denitrification tanks
• sedimentation tanks
• disinfection unit with ultraviolet radiation (U.V.)
• flow measurement unit in the exit
• gravity thickener
• drying beds
• leachate network – bypass pipelines
• buildings (administration building, warehouse, substation, etc)
• fencing - landscaping

The design of the facility’s expansion was based on the following data:

The proposed expansion project included:

• construction of a primary sedimentation unit upstream the biological treatment stage and an anaerobic sludge stabilization unit with parallel electricity production of approximately 200 kW from the exploitation of biogas.
• construction of an additional biological reactor with the relevant electrical and mechanical equipment (diffusers, blowers, mixers etc) and installation of two additional oxygen meters in the aeration tanks.
• construction of four tanks in the refining unit for the accommodation of filters.
• construction of an additional sludge gravity thickener – sludge dewatering system. 
• installation of deodorization system in the wastewater and septage reception pretreatment units.
• expansion of auxiliary networks and infrastructure to accommodate the new units.

In the accounted study the exact locations of the arrangements were identified, while the existing natural and human environmental conditions were investigated. In addition information on the feasibility of the project was provided, accompanied by a detailed technical description. Finally, the extent and magnitude of the environmental impacts emanating from the construction and operation of the project were identified and alternative solutions were proposed.

BENEFIT
The project was submitted to the public agency responsible for the renewal – alteration of the Environmental Permit and the relative decision was issued.