Environmental sustainability

Protecting the environment has always been a priority for the Impregilo Group, formalised since 2002 - among the first companies in Europe - in a specific Environmental Policy. Since then, the Group has implemented in all its operating companies an environmental management system certified to the ISO 14001 standard and able to ensure that environmental impacts are adequately identified and mitigated, in response to legislative requirements and the expectations of the communities affected by our projects.

Specifically, this system complies with Impregilo’s policy to protect the environment, not only for the purposes of sustainable development and success in global markets, but also for:

  • its strategic priority;
  • ongoing improvement in performance and conduct;
  • additional information and training for employees;
  • the  assessment  and  prior  limitation  of  the  effects  of  its  operations  on  the environment;
  • research and development, to identify increasingly sustainable techniques;
  • dialogue with employees and local communities, to jointly resolve any contingent environmental issues;
  • commitment to involving customers, suppliers and subcontractors in a more correct and evolved environmental management of their products and services.

The environmental management system allows Impregilo to continue its current policy aimed at:

  • ongoing improvement of environmental performances;
  • utilisation of an internal organisation to circulate and promote the system’s guidelines and instructions with all group companies and in building sites, ensuring their correct application;
  • developing the capacity to identify and monitor key environmental aspects of its core business, including by setting up special data bases;
  • the faster use of the results of technological research, encouraging adoption of increasingly efficient solutions to recycle materials, contain the movement and consumption of raw materials and energy, protect water resources and reduce waste and the clean-up of sites after work.

Large civil engineering projects have, by their very nature, very strong interrelationships with the anthropic and environmental environments in which they are implemented, modifying them to make them accessible (as in the case of transport infrastructures), to increase their economic potential (as in the case of dams for irrigation or energy) or to improve public utility services (as in the case of hydraulic engineering works).

The Impregilo Group is committed to providing the highest level of environmental protection in all stages of their construction works: from design to the construction phase, until clearing of the work sites and environmental restoration. Adopting the most advanced tools available, the Group evaluates all potential impacts arising from its activities, in order to eliminate or minimise them.

During project implementation, the Impregilo Group adopts specific environmental management plans in accordance with the requirements of ISO 14001, which allow all engineering works which could have effects on the environment to be monitored. The procedures of the environmental management system are applied in all our contracts and are constantly assessed and monitored, sometimes through direct  audits by  the QES Organisational Unit.

When a new contract is started and based on the work to be carried out, the group identifies significant environmental aspects, i.e., those aspects that could significantly impact the environment. Their identification and subsequent assessment take place using specific procedures designed by the Health, Quality, Environment and Safety Unit, applicable to all contracts.

The significance of environmental impacts is assessed using a methodology prepared considering criteria that are given different weights, depending on their importance. These criteria are:

  • the probability that the event will occur;
  • the seriousness for the environment;
  • how long the impact will last;
  • how difficult it will be to restore the original situation;
  • the effects on the group’s reputation.

Once the significant environmental impacts have been identified, the main effects of the contract on the different environmental components are analysed:

  • atmosphere,
  • natural resources and energy consumption,
  • surface and underground watercourses,
  • soil and subsoil,
  • waste generation,
  • noise and vibrations,
  • biodiversity,

which differ depending on the type of work carried out (underground tunnels and works, bridges and viaducts, railway and road works and dams).

Following the significance analysis, an Environmental Protection Plan will be prepared for each contract, describing the management and monitoring activities (Environmental Control Plans) for all the environmental components involved.


During construction of infrastructure, the most significant direct effects  on  the atmosphere relate to dust dispersion due to the nature of the key processes: excavation, earthwork, movement of heavy vehicles on dirt tracks, crushing plants and the demolition of existing structures and buildings. In addition, the engines of the building site equipment and self-generating power plants release atmospheric emissions.

The group adopts different methods to limit the creation and dispersion of dust: it regularly dampens access dirt tracks to building sites, vehicles are required to maintain a low speed. Industrial sites and quarries are equipped with tyre washing systems to prevent trucks from spreading dirt on roads, which would cause dust dispersion.

To reduce emissions of combustion gases and particulates low-impact methods are used: performing regular maintenance, periodically renewing plant, machinery and vehicles with more efficient and environmentally friendly models. However, the main opportunities for reducing emissions derive from the connection of the plant and installations of the Group to local power networks, reducing, where possible, the use of diesel generators. For this reason, Impregilo carefully assesses the possibility and means of connecting their sites to existing electrical networks.

Natural resources and energy

Construction of motorways, bridges, dams and railway lines requires the use of large quantities of concrete, water, iron and backfill: all raw materials which are mostly not renewable.

Impregilo is committed to ensuring the most efficient use of these resources and the use of alternative materials, when possible, without affecting the quality, security and functioning of the finished product.

In order to improve its environmental performance, Impregilo has fine-tuned systems to recycle and reduce consumption. When possible, it recycles debris as part of the same contract or uses systems that allow the reuse of water for other specific activities, such as, for example, washing vehicles.

Energy consumption, both in the form of fossil fuels and electric energy, has a strong impact during construction of infrastructure. Reduction of energy consumption is possible by using more efficient equipment or low-consumption vehicles.

Impregilo uses state-of-the-art power rationalisation systems both in the works it constructs and at its building sites, preferring high efficiency means and equipment.

Water environment

The effects of construction of a large-scale work on surface or underground watercourses are never insignificant. The impact varies depending on the type of work. Construction of a bridge or a dam inevitably leads to interference of watercourses. Impregilo has procedures to minimise the effects on the habitats of acquatic flora and organisms and on the quality of the water.

Tunnel boring also unavoidably leads to interference of underground watercourses. This is normal in all tunnel work but may become a critical issue if there are large waterbeds. Impregilo adopts the techniques necessary to leave the existing situation as unchanged as possible and to avoid any sort of contamination.

To prevent contamination, wastewater is properly channelled and collected in leakproof sedimentation tanks and treatment plants, where sediment and oily residues are removed. Prior to their release into the environment, the Group closely monitors the quantity and quality of its water discharges, to ensure compliance with local laws.

Even the water from underground excavations is collected and treated in treatment plants constructed at the entrance to the excavation windows, in order to eliminate any trace of pollutants or suspended matter before the water is returned to the environment.

Soil and subsoil

Large-scale works and infrastructure always affect the soil: use of the surfaces, sealing, excavations and backfills, contamination risks.

Earthwork and excavations are one of the most obvious and typical aspects during construction: construction of embankments, cuttings or certain types of dams require the movement of large earth quantities. Large volumes of soil have to be moved to the work front or removed. When the earth does not come from excavations at the building site, the effect on the environment of using earth from quarries or other natural environments has to be considered.

The primary and most visible environmental impact in the case of underground works is the large quantity of material created by the tunnel boring activities and the related traffic due to transport of the muck

The excavated earth and rock are classified and stored on the sites for possible re-use within them, where possible and in compliance with the regulations, or sold to third parties to be re-used externally.


Waste generated during construction of large-scale infrastructure and engineering works can be grouped into two separate categories: urban or similar waste and special waste. Urban or similar waste is generated by logistics sites where all the support activities for the industrial production are carried out such as offices, accommodation for non-resident workers, canteens and recreational facilities for workers.

Impregilo avails of the services of local authorised companies for waste collection, recycling and disposal.

Special waste is generated by the actual industrial activities. It includes cement residue and iron scraps, which are usually recycled.

On industrial sites, waste materials are collected and sorted, and stored in specific enclosed areas, from which they are then taken to be reused or to be sold to third parties authorized to carry out disposal and treatment of waste.

Other types of waste generated in large quantities are packaging (plastic and wood) and sludge from the water purification systems, which are transferred to specific authorised third party systems.

Hazardous waste is a marginal part of the waste generated in a large-scale infrastructure contract. Normally it involves paint, additives and solvents, used oil and oil filters from vehicle maintenance, batteries, rechargeable batteries and, in some cases, earth, mud and other materials containing hazardous substances.

Impregilo transfers its hazardous waste to authorised third parties.

In all cases, Impregilo operates in compliance with the current legislation and with maximum care, using qualified suppliers if necessary.

Noise and vibrations

The aspects relating to noise and vibration have a double significance for the Impregilo Group: internally, in terms of the health of workers, and externally, in terms of impacts on the environment and local communities.

Within its integrated management system, there are specific procedures to evaluate and monitor these aspects, adopting the most appropriate measures to ensure protection of the health and safety of workers (use of personal protection equipment, soundproofing, etc.) and of the surrounding environment.

With regard to the effects on the environment surrounding the sites, the areas most subject to noise interference are protected by noise barriers, which can be artificial dunes made of backfill material or support structures and absorption panels made of various materials. The noise barriers could also be one or more rows of trees or shrubs which both absorb the noise and reduce the visual impact.

Vibration is also a feature of work on civil engineering sites. The effects of pressure waves that propagate in the soil can cause damage to buildings or other structures located in the vicinity  of  the  works.  Thus,  for  example,  when  compacting  an  embankment,  it  is important to study the geomorphology of the land in order to understand in advance how vibrations will propagate in the ground, and then identify the best working techniques.

During the works, periodic monitoring of both noise and vibration is carried out. Where it is critical that disturbance be limited, the working time of machines is reduced to prevent disturbance to the people and buildings concerned.


The performance of infrastructure projects requires the implementation of special protection measures when the sites are adjacent to or within sites of special natural interest, so that construction activities interfere as little as possible with the fauna and flora present. In these situations, the Group makes extra efforts in terms of monitoring and mitigation measures, undertaking to preserve and protect the biodiversity of the areas surrounding its operational sites.

Impregilo works closely with local authorities in order to ensure full compliance with the applicable legislation. The protection  of flora and fauna is obtained by careful management of water, the working areas, quarries and areas used for storing rubble and waste materials.