This document serves as the 4th annual Report for the monitoring of environmental impact of the Project entitled “Archaeological Works and Relocations of PUO Networks of Line 4, Section A’: Alsos Veikou – Goudi of the Athens Metro”; it concerns the time period from 01.01.2025 until 31.12.2025 and the following five worksite locations of the Project, namely:
- KYPSELI Station
- ALEXANDRAS Station
- EXARCHIA Station
- PANEPISTIMIOUPOLI Station
- ZOGRAFOU Station
ENVIRONMENTAL IMPACT OF THE PROJECT AND REMEDIAL MEASURES
Natural Environment
Air
Air impact during the execution of works can be mainly caused during the execution of archaeological works and the PUO network relocations that integrate traffic arrangements, dismantling and removal works. Moreover, limited and short-term impact can be caused during the transfer of excavation spoil and construction materials to and from the worksite areas.
In view of reducing and controlling air pollutants in the atmosphere, appropriate measures concerning prevention of emission and their dispersion in the urban environment were introduced. These measures include the following, namely:
- Keeping vehicle and machinery exhausts away from the soil, so as not to favor the generation of dust during their operation.
- Regular maintenance of equipment/vehicles/machinery for the proper operation and reduction of fume emissions. In line with the applicable legislative requirements, Project vehicles and machinery possess a technical inspection report and an exhaust control card, issued by the Vehicle Technical Control Centre (KTEO).
- Εco driving mode of the vehicles to reduce fuel consumption and fume emissions, moving at low speed to reduce dust.
- Prohibition of burning residues from cleaning works, excavations and dismantling works, as well as any kind of materials.
- Reduction to the minimum possible the duration of works favoring and/or generating dust.
During the reference period and based on the available data, no negative impact on the air quality, due to the execution of works, has been identified and recorded. Taking into consideration the information included in the approved Environmental Impact Assessment Studies (EIAS) and supplementary Environmental Studies of the Project, as well as the Technical Environmental Studies for worksites, the emissions of air pollutants are estimated to be local, mild and short-term and are not expected to negatively and significantly affect the air quality in the wider area of the locations where works have been executed.
Water Resources
During the reference period and based on the available data, no negative impact on the water quality have been identified and recorded due to the execution of works, and more specifically, during the performance of archaeological works and PUO network diversions, including traffic arrangements, as well as demolition and dismantling works.
It is noted that during the reference period no water pumping works have been executed and, thus, no settling tanks have been installed.
Moreover, no washing activities of Project vehicles, machinery and other equipment are performed in the worksite areas.
Soil
During the reference period and based on the available data, no negative impact on the soil has been identified and recorded due to the execution of works, and more specifically, during the execution of archaeological works and PUO network diversions, including traffic arrangements, demolition and dismantling works, as well as during the transfer of excavation spoil and construction materials to and from the worksite areas.
Flora
The impact identified on the urban green during the reference period throughout the execution of works concerns grubbing and cutting of the existing trees and bushes due to the works under execution, i.e. during the execution of archaeological works and PUO network diversions, including traffic arrangements, demolition and dismantling works.
In order to avoid any negative impact on the flora and the urban green in the worksite areas, the following measures have been introduced:
- Transplantation of trees and bushes to the Plant Nursery of the Municipality of Athens, following the suggestion of the Greenery Division of the Municipality of Athens.
- Tree care (pruning) provided to all trees prior to the execution of grubbing and transplantation works.
- Tree care (placing fertilizer, watering works etc.) provided to all trees transplanted to the Plant Nursery of the Municipality of Athens, as suggested.
- Transplanting trees and bushes that can be transplanted at proper locations following the suggestion of the Agencies concerned (Greenery Divisions of the Municipalities concerned).
- Removal and handling of prunings, as well as trees and bushes that have been cut and cannot be transplanted in an appropriate licensed plant.
- A Special Study for the Management of Urban Green and Flora is prepared and submitted for approval to ELLINIKO METRO S.A. for every location of the Project, based on which cutting, grubbing and transplantation works of the existing flora are being executed.
The trees and bushes to be transplanted are marked by the Greenery Divisions of the Municipality concerned and, where required, the Department of Forests of Athens and the Department of Woods and Parks of Attica Prefecture give their expert opinion for the subject trees and bushes to be transplanted to locations suggested by the aforementioned Divisions. The remaining trees and bushes that are not transplanted are being properly handled in cooperation with Plants licensed for the removal and disposal/recovery of biodegradable waste (EKA – European Waste Catalogue code 20 02 01: garden and park wastes – biodegradable waste).
Built Environment
During the reference period and based on the available data, no negative impact on the built environment within and adjacent to the worksite areas has been identified and recorded. Impact, if any, that may be caused during the execution of all works concerns buildings, the road network, the infrastructure networks and the common infrastructures.
Citizens’ Quality of Life
Noise – Vibrations
During the reference period, the impact on the quality of life of the citizens in the areas of the project locations where works have been executed, generated by noise and vibration emissions, is estimated to be of local character, mild and short-term without adversely affecting – to a great extent – the quality of the urban environment in the wider area of the locations where works have been executed, taking also into consideration the results of the noise and vibration measurements carried out during the reference period at the most heavily affected – in terms of works – and sensitive worksites’ locations.
The impact on the quality of life of the residents in the areas of the project locations and on the acoustic environment, due to noise and vibration noise and vibration, may be caused mainly during the execution of archaeological works and the works for the diversion of the PUO networks, including traffic arrangements, demolition and dismantling works. Moreover, mild and short-term impact may be caused during the transportation of excavation spoil and construction materials to/from the worksite areas.
Such impact concerns the following:
- Generation of noise emissions due to the operation of project machinery, work equipment and the circulation of project vehicles and machinery in the worksite area
- Generation of vibrations due to the operation of project machinery, work equipment and the circulation of project vehicles and machinery in the worksite area.
To limit the generation of noise and vibration emissions, the following measures are introduced:
- Use of equipment ensuring effective noise attenuation, such as appropriate silencers, noise insulation, acoustic barriers, soundproofing, noise-shielding, etc.
- Frequent maintenance of the equipment to ensure that the equipment is kept in good condition, so as to minimize noise emissions during use.
- Τechnical inspection report issued by the Vehicle Technical Control Centre (KTEO) for vehicles transporting the construction materials and excavation spoil while noise levels emitted during operation are checked against the applicable legislative requirements.
- Installation of the equipment as far away as possible from the adjacent buildings.
- Avoiding concurrent operation of machinery causing the emission of high noise levels and vibrations (air compressors, drilling rigs, hammers, pilling machinery, road rollers etc.) and operation during rest hours.
- Loading, unloading trucks and machinery and driving same to ensure the lowest possible noise levels.
Accessibility
During the reference period, based on the available data, no major negative impact has been identified and recorded on the accessibility of people to public areas, properties, commercial shops and work areas. Any impact is estimated to be of local nature and mild, while the impact shall extend throughout the period of the execution of the works.
It is pointed out that due attention is taken, so that in all project locations the least possible surface is occupied for the needs of the execution of the works and for time schedule adherence purposes, so that the areas occupied are released on time.
Cultural heritage
The impact on cultural heritage during the execution of the works could be mainly caused due to the relocation of PUO networks. To avoid any negative impact on the historical and cultural environment, special attention is taken for the protection of the archaeological findings which could be encountered during the execution of the works.
More precisely, prior to the commencement of the works, investigation works, where required, were executed at the individual project locations to identify any eventual antiquities, including the required retaining and/or supporting works. The points of interest for drilling investigation sections are set by the Archaeological Department, which is notified in writing prior to the commencement of the works. The archaeological works to follow are executed under the supervision of the Archaeological Department.
During the reference period, no negative impact on cultural heritage has been ascertained and recorded due to the execution of the works. Should finds are revealed during the archaeological investigation, the impact shall be positive, since the findings will be rescued, preserved and displayed.
Handling of excavation spoil and excavation, construction and demolition waste
As regards the handling of excavation spoils and the waste generated during the execution of the works in the worksite areas, a log and the relevant documentation (transportation accompanying documents, acceptance certificates, dispatch notes, etc.) are kept, in view of documenting how every waste category is disposed. The permits of the disposal sites for excavated material and the relevant approvals and documentation were submitted through the Special Study for Handling Excavation Spoil and Construction Materials.
In line with the provisions of the approved Environmental Monitoring Plan of the project and the approved Special Study for Handling Excavation Spoil and Construction Materials, exceeding excavation materials may be transported for disposal in approved areas. During the reference period, the majority of the generated excavation, construction and demolition waste which resulted from the execution of the archaeological works and the works for the deviation of the PUO networks, including traffic arrangements, demolition and dismantling works, were transported for disposal in licensed disposal sites.
Biodegradable waste generated from cleaning works in the worksite areas (European Waste Catalogue code 20 02 01) which concerns the urban green which cannot be transplanted and biodegradable waste generated from the cleaning works in worksite areas (grass, dry branches, etc.) were disposed for handling in licensed companies.
CONCLUSIONS
Based on the analytical data for the reference period, i.e. from 1/1/2025 to 31/12/2025, no negative impact has been ascertained or recorded during the execution of the project “Archaeological works and PUO relocations in Athens Metro Line 4 – Section A “Alsos Veikou – Goudi”.
ANNUAL ENVIRONMENTAL REPORT 2025
MAIN CONSTRUCTION PROJECT OF ATHENS METRO LINE 4
1. CONSTRUCTION WORKS FOR THE ATHENS METRO LINE 4
This document serves as the 4th annual Report for the monitoring of environmental impact of the Project entitled “Line 4, Section A’: Alsos Veikou – Goudi” of the Athens Metro, it concerns year 2025 and, more specifically, the time period from 01.01.2025 until 31.12.2025 and the following worksite locations of the Project, namely:
- Katehaki TBM 2 Shaft
- Veikou TBM 1 Shaft
- GALATSI Station
- ALSOS VEIKOU Station
- ELIKONOS Station
- KYPSELI Station
- DIKASTIRIA Station
- ALEXANDRAS Station
- AKADEMIA Station
- KOLONAKI Station
- KESSARIANI Station
- ILISSIA Station
- ZOGRAFOU Station
- Evangelismos Trumpet Shaft
- GNA Shaft
- VEIKOU Shaft
- EYDAP Shaft
- Dikaiossynis Shaft
- Vivliothiki Shaft
- Building of the new OCC in Sepolia
2. ENVIRONMENTAL IMPACT OF THE PROJECT AND REMEDIAL MEASURES
In the framework of this report, evaluation is made of the environmental impact from the construction of the Project in the natural and man-made environment and presentation is made of all measures implemented in order to deal with this impact, in compliance with and adhering to the applicable legislation and the Approved Environmental Terms of the Project.
Impact during the construction of the Project on the following environmental parameters are under examination, namely:
- Soil characteristics
- Water resources
- Atmosphere
- Acoustical environment
- Technical infrastructures – networks
- Urban green
- Waste management
The aforementioned impact is assessed as non-significant, moderately significant and practically zero. Impact is also distinguished into permanent or non-lasting, depending on the duration of the impact. In general, permanent impact is considered as the impact still in effect after the completion of the construction of the Project, while non-lasting impact is the one that ceases to exist after the completion of the Project construction period.
Finally, impact can be divided into reversible or irreversible, depending on the potential of the impacted environmental parameters to reverse the aforesaid impact back to its original state (prior to the construction of the project), further to the introduction of a series of remedial measures, if required.
2.1 SOIL
The main construction works that have been executed during the reference period of the subject report (2025) and can be related to any impact on the soil are as follows:
- Excavation works
- in KOLONAKI, AKADEMIA, DIKASTIRIA, GALATSI, ALSOS VEIKOU, ELIKONOS, ALEXANDRAS, KESSARIANI, ZOGRAFOU and ILISSIA Stations
- in GNA, VEIKOU TBM, EYDAP, DIKAIOSSYNIS, VIVLIOTHIKI, EVANGELISMOS TRUMPET Shafts,
- in TBM1 and TBM2 tunnels
- in the NATM tunnels of the forestations of GNA and VEIKOU Shafts as well as
- in the new OCC in Sepolia
- Disposal of excavation spoil.
Impact assessment and measures to address the relevant impact
- Excavation works
Excavation works entail changes on the soil related to the local change of the characteristics of the relief of the soil in the restricted area of the Project worksites.
Excavations are carried out in accordance with the approved designs of the Project, implementing at the same time all the foreseen retaining measures in order to avoid any changes on the mechanical characteristics of the adjacent geological formations. At the same time, instruments and a direct monitoring system of the geological formations’ displacements have been installed in the excavation areas, so that –if required- all necessary measures can be introduced.
Thus, any impact due to the excavation works is limited and short-term and this impact shall be fully eliminated after the construction and backfilling of the Project’s Stations, Tunnels and Shafts, since the subject areas are reinstated in terms of morphology, upon the completion of the construction works, in accordance with the approved morphological and phyto-technical landscaping studies .
- Disposal of excavation spoil
The redundant excavation spoil is transferred to be disposed in licensed and approved disposal areas. Licenses for the excavation spoil disposal areas as well as the respective approvals and back-up documentation have been submitted along with the Special Study for handling Excavation Spoil and Construction Materials.
The aforementioned works for the disposal of the excavation spoil have a positive impact on the environment since, until the present date, the entire quantity of the excavation spoil has been used for the needs of other projects (reinstatement of quarries, backfilling – covering materials, cement production).
Therefore, a positive balance of earthworks has been created between the disposal areas and the excavations of the Project.
2.2 WATER RESOURCES
The most important construction works that have been executed during the reference period concerning the subject report and can be related to any possible impact on the ground and surface water are as follows:
- Excavation – retaining works
- in KOLONAKI, AKADEMIA, DIKASTIRIA, GALATSI, ALSOS VEIKOU, ELIKONOS, ALEXANDRAS, KESSARIANI, ZOGRAFOU and ILISSIA Stations
- in GNA, VEIKOU TBM, EYDAP, DIKAIOSSYNIS, VIVLIOTHIKI Shafts and in EVANGELISMOS TRUMPET SHAFT
- in TBM1 and TBM2 tunnels
- in the NATM tunnels of the forestations of GNA and VEIKOU Shafts as well as
- in the new OCC in Sepolia
- Water pumping and management from the aforementioned excavation fronts.
Impact assessment and measures to address the relevant impact
The aforementioned works can potentially affect the existing water condition in the following cases:
- Through the uncontrolled disposal of liquid waste from the worksite installations or work areas (e.g. machine washing water, vehicle wheel washing water)
- Through the uncontrolled disposal of water deriving from excavation and drilling activities, when these activities take place at a level lower than the ground water table level
- Through water consumption for the execution of construction activities (e.g. sprinkling water to excavation fronts, to surfaces for vehicular traffic etc.) and green related works.
In order to prevent and address impact and in compliance with the Environmental Terms of the Project, the following measures were introduced:
- Construction of water collection and settling pit for the water deriving from vehicle’s washing activities at the worksite areas exiting point
- Installation and operation of automated units for cleaning water pumped from TBM1 and TBM2 worksites
- Installation of settling tanks in the worksite areas for cleaning pumped water
- Monthly sampling of pumped water from the settling tanks of all worksite areas and performance of chemical analyses to control adherence to the applicable legislation
More precisely, 564 chemical analyses were executed in all the worksites where systems for cleaning the underground pumped water have been installed
- Monthly recording of the consumption of the natural resource named “water”, through the procedures foreseen in the Contractor’s ISO 14001 system, in view of using water rationally for covering the construction works’ needs in all worksite areas.
During the reference period and based on the above, negative impact from the execution of the construction works has been neither identified nor recorded.
2.3 AIR
The main construction works that have been executed during the reference period of the subject report that can be related to eventual impact on the air are as follows:
- Excavation and retaining works
- in KOLONAKI, AKADEMIA, DIKASTIRIA, GALATSI, ALSOS VEIKOU, ELIKONOS, ALEXANDRAS, KESSARIANI, ZOGRAFOU and ILISSIA Stations
- in GNA, VEIKOU TBM, EYDAP, DIKAIOSSYNIS, VIVLIOTHIKI and in EVANGELISMOS TRUMPET Shafts
- in TBM1 and TBM2 Tunnels
- in the NATM tunnels of the forestations of GNA and VEIKOU Shafts as well as
- in the new OCC in Sepolia
- Use and operation of machinery on soil surface or non-cladded surfaces (e.g. excavators, drilling machines, loading machines)
- Traffic of mainly heavy vehicles on the soil surface of the worksites
- Transfer of excavation spoil and construction materials of the Project using heavy vehicles.
Impact assessment and measures to address the relevant impact
In view of preventing and counteracting the effects of pollutant loads, the following measures have been introduced in accordance with the Environmental Terms of the Project:
- Systematic water sprinkling of all soil surfaces within the worksites to avoid dust dispersion.
- Laying the areas where vehicles circulate within the worksites using road paving material and concrete.
- Water sprinkling of excavation materials before leaving the worksite areas and being transferred to the relevant disposal areas.
- Transfer of excavation spoil by covering the muck vehicles using the appropriate protective cover.
- Washing the vehicles wheels when exiting the worksite.
- Cleaning the streets adjacent to the worksites using a self-propelled sweeper.
- Preparation and use of a specific schedule for the transfer of excavation spoil and construction materials of the Project.
- Regular maintenance of equipment/vehicles/machinery for the proper operation and reduction of fume emissions.
- Execution of monthly measurements of the concentration of PM-10 – PM-2.5 and NO2 particles in the air (in accordance with the Approved Monitoring Program of Particles and NO2). In total, 300 daily (on a 24-hour basis) measurements have been executed in all worksite areas of the Project.
During the reference period and based on the above, there are no recordings about concentrations in the air exceeding the limit values set in the applicable legislation. Therefore, the emissions of air pollutants due to works executed until the present date are local, mild and short-term and are not expected to affect the air quality in the wider area of the works and, thus, are not considered severe as regards their impact.
2.4 NOISE – VIBRATIONS
The main construction works that have been executed during the reference period of the subject report and which can be associated with any eventual impact on the environment due to noise are as follows:
- excavation and retaining works:
- in KOLONAKI, AKADEMIA, DIKASTIRIA, GALATSI, ALSOS VEIKOU, ELIKONOS, ALEXANDRAS, KESSARIANI, ZOGRAFOU and ILISSIA Stations;
- in GNA, TBM VEIKOU, EYDAP, DIKAIOSYNIS, VIVLIOTHIKI and EVANGELISMOS TRUMPET Shafts
- in TBM1 and TBM2 tunnels
- in the NATM tunnels of the forestations of GNA and VEIKOU shafts
- as well as of the new OCC in Sepolia.
- Use and operation of Project construction machinery
- Traffic of heavy vehicles to and from the worksite areas.
Impact assessment and measures to address the relevant impact
In order to prevent and deal with any impact mainly on the man-made environment and in accordance with the Environmental Terms and Environmental Specifications of the Project, the following measures have been introduced:
- Preparation and implementation of a Special Noise and Vibrations Study for each worksite area.
- Installation of metal acoustical panels for noise reduction in all worksite areas that have been occupied.
- Scheduling of works to avoid the execution of noise generating works during rest hours.
- Briefing residents of adjacent properties if noise generating works are under execution.
- Use of machinery with the relevant EC type approval certificate for noise.
- Use of movable soundproof partitions for machinery.
- Avoidance of concurrent operation of machines generating high levels of noise and vibrations (air compressors, drilling machinery, hammers, piling machinery, road rollers etc.) as well as their operation during rest hours.
- Execution of monthly noise – vibration measurements in all worksite areas in which works are under execution, in accordance with the approved Noise and Vibrations Control Schedule and based on the results of the approved Special Noise and Vibration Study.
More specifically, the following works were executed:
- 176 daily (on a 24-hour basis) noise measurements in all worksites in operation
- 9 vibration measurements at locations specified in the Decision for the Approval of the Environmental Terms of the Project during the passage of the two TBMs under sensitive receivers
- 22 vibration measurements during drilling works of prestressed anchors near sensitive receivers
- 12 vibration measurements during drilling works of shaft piles near sensitive receivers.
During the reference period, based on the above, the noise and vibration levels from the works executed until the present date are relatively low, while zero decibels are recorded once the individual noise generating works are completed; thus, their impact is not considered severe.
2.5 IMPACT ON THE TRANSPORTATION NETWORKS – INFRASTRUCTURES
The main construction works that have been executed during the reference period of the subject report and which can be associated with any eventual impact on the existing infrastructure and transportation networks are as follows:
- Occupation of worksite areas
- Traffic arrangements in the worksites’ occupation areas
- Traffic of heavy vehicles for the transportation of excavation spoil and the construction materials to and from the worksites.
Impact assessment and measures to address the relevant impact
- Preparation and implementation of traffic arrangement designs approved by the Services concerned in the worksite installations’ areas.
- Preparation and implementation of approved traffic schedule of heavy vehicles, specifying the main traffic roads to and from the worksite.
- Specified trips, based on the aforementioned schedule, of the vehicles for the transportation of excavation spoil and construction materials to and from the worksites, aiming at avoiding residential areas to the extent possible.
- Circulation of heavy vehicles through the main road axes of the wider area of the Project, which (axes) can withstand without any problems the additional traffic load, while traffic in the local access roads to and from the worksite areas is carried out following communication with and approval by the local authorities concerned.
- Cooperation with the local authorities concerned as regards the traffic management.
- Installation of traffic signs (cones, light signals, signs etc.) to warn drivers and pedestrians about the risks due to the execution of works and to assist in the normalization traffic around the worksites.
- Presence of signaler at the entrances – exits of worksite areas for the safe and smooth traffic arrangement during vehicles entering – exiting from the worksites.
- Construction of sufficient and safe pedestrian crossings and accesses in work areas, residential areas and shops (sidewalks, ramps etc.), as required, in accordance with the traffic studies.
- Immediate repair of any damage due to construction works, caused to the existing road network outside the worksite boundaries.
- Frequent cleaning of the local road network adjacent to the worksite areas.
During the reference period, based on the above, no significant negative impact has been either identified or recorded on the accessibility of citizens to public areas, properties, shops and work areas. Any impact whatsoever is considered as local, mild and lasting for the time period during which works are under execution.
2.6 URBAN GREEN
Any impact identified during the reference period stated herein on the urban green, in the areas of worksite occupations, concerns the removal of existing trees and bushes due to construction works under execution.
Impact assessment and measures to address the relevant impact
In order to avoid any negative impact on the flora and the urban green in the worksite areas, the following measures have been introduced:
- Transplantation of those types of trees and bushes that can be transplanted in areas adjacent to worksites, following the suggestion and the relevant permit issued by the Services concerned of the relevant Municipalities.
- Planting of new trees in areas adjacent to the worksites, following the suggestion and the relevant permit issued by the Services concerned of the relevant Municipalities.
- Removal of trees and bushes that cannot be transplanted, following the relevant permit issued by the Services concerned, in an appropriate licensed plant for further handling.
- Submittal for approval to ELLINIKO METRO S.A. of a Special Study for the Management of Urban Green and Flora for each worksite area, including the overall management of the existing flora and the specifications concerning the transplantation works.
2.7 WASTE TREATMENT
Waste generated by the Project’s construction activities performed until the present date includes the following:
- Urban waste from the project personnel.
- Waste from the operation of the worksite offices, such as paper, empty ink packages, lamps, electric – electronic devices.
- Waste from material packaging, such as paper packaging, cartons, plastic – plastic packages, metal packages, wooden pallets.
- Steel reinforcement scrap.
- Waste from mineral oils’ – lubricants’ packages.
- Urban waste from worksites.
Actions undertaken by the Contractor
In order to prevent and address impact on the natural and man-made environment from the disposal of the aforementioned waste, the following measures have been implemented:
- Urban waste is placed in litter bins and is collected by garbage trucks of the Cleaning Services of the relevant Municipalities.
- Paper and plastic waste from the operation of the worksite offices are collected in small bins bearing the appropriate signage, located in the worksite offices and are subsequently placed in recycle bins. Recycling is effected by the Cleaning Services of the relevant Municipalities.
- Installation of special bins in the worksites to collect any type of waste separately.
- Conclusion of contracts with licensed treatment companies and collective systems of alternative treatment for the disposal of all types of produced waste.
- Full recording of all waste treatment by implementing ISO 14001 system.
