Building railway infrastructure with less pollution

Building railway infrastructure with less pollution

The importance of the train from an economic point of view is beyond dispute. It emerged as one of the most extraordinary innovations in the Industrial Revolution, because although it is true that the first steam locomotives had already been created before, it was during this period when the potential of this new means of transport could be seen.

Over the years, it has become one of the preferred means of transport for citizens, because of its safety and speed, only surpassed by the airplane. Furthermore, in contrast to the use of private vehicles, rail service contributes to fuel economy per passenger and is therefore more sustainable than other means of transport.

According to data from ADIF (Administrator of Railway Infrastructures), in Spain a train passenger consumes 5 times less litres of petrol equivalent per kilometre than traveling by car, and 20 times less than traveling by airplane. Or, for example, transporting one tonne of goods by rail consumes 4 times less litres of petrol equivalent than by road, and 1,380 times less than by air.

But, what about the construction of the railway infrastructure necessary for the movement of trains? Is it sustainable?

This was the premise of the LIFE HUELLAS project, led by CARTIF, together with the companies Vias y Construcciones and IK-Ingeniería and the University of Granada. Its objective was to improve the construction process of railway tracks in terms of their environmental impact, with special emphasis on those aspects that affect climate change.

It should be borne in mind that the railway infrastructure is made up of civil works such as bridges, viaducts, tunnels and service roads, and of the superstructure, made up of rails, sleepers, fastening material, and electrification, signalling and track safety installations. The production, construction and maintenance of all this infrastructure has a high environmental impact.

The LIFE HUELLAS consortium considered that life cycle assessment techniques, combined with intelligent data analysis, could help reduce the carbon and water footprint of railway infrastructure works by 10% and 5% respectively.

After four and a half years of intensive work, the project has managed to reduce an average of 12.9% of the carbon footprint and 14.1% of the water footprint per kilometre built in the works that have been used as pilots, i.e. better results than expected. Quite a success.

The project began with an exhaustive collection of basic information to analyse the environmental impact of the construction of railway networks, based on previously identified variables. Later, participating companies focused their efforts on studying the transformation of environmental impact into carbon and water footprints, through the development of a consolidated assessment methodology.

From this compilation, a smart tool will establish different planning alternatives applying computational intelligence techniques and showing specific values of footprint and previously selected environmental indicators. That is to say, the objective is to help in the decision-making process during the planning phase of the works.

Furthermore, the research team has developed a free online tool that provides a detailed environmental diagnosis of the processes involved in the construction of this type of infrastructure. This tool, available on the project website, allows the development of railway projects with not only economic, but also environmental and social criteria.

For the development of both tools, the consortium has exhaustively studied more than 460 project units and a collection of relevant sustainability variables and indicators, grouped in:

  • Environmental indicators: carbon and water footprint, acidification potential, photochemical oxidation and eutrophication.
  • Social indicators: improving working conditions, health and safety, human rights, governance, community infrastructure and job creation.
  • Economic indicators: project costs.

Tests were carried out during the demonstration phase of the project in two real works; on the one hand, the Ponte Ambía (Orense)-Taboadela (Orense) section of the Madrid-Galicia high speed line for the track infrastructure, that is for the earthworks (embankments, trenches, tunnels, etc.) and for the factory works (bridges, drainage, viaducts and level crossings); and on the other hand, the Antequera (Málaga)-Loja (Granada) section, for the track superstructure over which the trains run, whose main elements are ballast, sleepers, rail, electrification and signalling.

With the aim of contributing to these processes in terms of sustainability, the consortium has compiled in a guide of Good Practices the main conclusions of the experience acquired during the development of the project, as well as the different sustainable alternatives proposed.

Although LIFE HUELLAS project has already been completed, railway works on which it has been validated have effectively reduced the carbon and water footprint of their construction phase, contributing to the environmental improvement.

In addition, free access to the calculator will remain available at for anyone to use. You can also find us at networking and dissemination events, transferring gained knowledge, since the objective now is to promote replicability by communicating obtained results to other companies and sectors. For example, many of the railway infrastructure construction operations are common to those that build other infrastructures, such as roads, so they can also benefit from the results of the project.

Sustainable public procurement and open data

Sustainable public procurement and open data

The Sustainable Public Procurement Initiative (SPPI) is nowadays the key policy instrument to promote sustainable development and move towards a green economy that fosters the development of products and services maximizing social and environmental benefits. EU public procurement directives oblige contracting authorities to base tendering decisions on the most economically advantageous tender (MEAT) principle, focusing on life-cycle costs and environmentally and socially sustainable products. Member States should generally promote the whole life-cycle cost analysis as standard practice in long-term investment.

Transport infrastructure investments have a positive impact on economic growth, creates wealth and jobs, but it has to be done in a way maximises these positive impacts and minimises negative impact on the environment. Specifically, rail transport causes 0.2% of global emissions in EU27. Infrastructure supposes 28% of these emissions, half of them caused during construction. This shows the high environmental impact of these activities.

According to the IODC post “Fighting climate change: the ultimate data challenge”, data are most powerful when they are available as open data and scientists are using data not only to monitor climate change but to help provide solutions, combining data science with climate science.

In line with these ideas an initiative, partially supported by LIFE+ Programme of the European Commission, combines life cycle assessment (LCA) techniques with intelligent data analysis, in order to improve sustainability of railway infrastructure construction processes as a whole, considering environmental, economic and social aspects. The goal is to reduce carbon and water footprints of railway infrastructure construction projects from their earliest stages, i.e. design and planning processes.

On a recent keynote speech, Martina Werner, member of the European Parliament and the ITRE Committee on Industry, Research and Energy, argues that many manufacturers concentrate on competing mainly on the basis of the mere purchase price. A thorough implementation of the procurement directives and particularly the MEAT principle gives suppliers a competitive advantage. Numerous factors now can be taken into account during the procurement procedure. This includes the reliability of the supply chain, services, maintenance costs, environmental factors and criteria of corporate social responsibility.

Based on environmental and social impact of most relevant tasks, an Open Access tool provides selected specific footprint values and environmental & social indicators as open data to the community, promoting the incorporation of environmental criteria on construction projects. This tool is available online, with all the information regarding LCA and Social LCA (SLCA) and it is intended for spreading the word on sustainable development and paving the way for the use of this or similar tools by public bodies or bidders.

C&D waste management around the world

C&D waste management around the world

Construction and Demolition Waste (C&D Waste or CDW) includes all the waste from the construction of new buildings, demolition of old ones and small refurbishment works. The generation and management of CDW is a serious environmental problem. Neglect or mismanagement produce negative impacts and can cause water, ground and air pollution, contributing to climate change and affecting ecosystems and human health.

Current regulations on CDW management determines the need for an ex-ante estimation of the debris type and volume a project will generate. The level of detail and accuracy should be adequate to allow an effective planning to carry out the management of this waste.

Concern about the amount of CDW generated and its environmental impact is growing. For this reason, governments and public authorities are reviewing their policies on how these wastes should be managed. In order to improve this management, it is necessary to know the composition and magnitude that should be dealt with, as well as some estimating method of waste generated in a project, in a region or a country.

Despite all the problems that CDW may cause, and difficulties on their treatment, when waste is properly managed become resources, or products that contribute to saving raw materials, conservation of natural resources, avoid climate change and thus to sustainable development, in accordance with the principles of the circular economy.

How to estimate the waste generated by construction and demolition activities varies significantly from place to place, as explained below.

In the United States, USEPA (US Environmental Protection Agency) estimates the amount of CDW generated in a specific region only from the built-up area, but regardless of whether the building is residential or not, or whether the works are new construction, refurbishment or demolition, which influences the type and amount of produced waste.

Another interesting case is Brazil, because it is an emerging country but CDW legislation is very similar to the European one, particularly the Portuguese. In this country, the civil construction sector is an important waste generator and national laws require manufacturers to take responsibility for the waste generated in their work and planning their management. A very important part of this effort is waste estimate to be generated, differentiating by waste type (brick, wood, glass, etc.) as each need a suitable deposit space and will be treated differently.

The situation in Asia varies greatly from one country to another. Except for Korea and Japan, lack of knowledge and awareness of efficient building practices results in natural resources overuse and generation of large amounts of CDW that is rarely recycled. Approximately 40% of the total generated waste comes from construction and demolition activities. This waste is  difficult to manage because it is heavy and bulky and can not be incinerated or used for composting.

The European Union, in the EWC (European Waste Catalogue) provides a classification of the CDW by category. According to statistics, there are huge differences in recycling and recovery rates between EU countries, between less than 10% and over 90%. In Spain, recycling rate is around 65% of generated CDW. Construction companies benefit from the reduced amount of generated waste by reducing landfilling associated costs and reducing raw materials purchasing budget.

CDW Management in Spain
Most of not recycled waste, at best, goes to landfills, taking up large discharge spaces and causing faster filling. In Spain, CDW estimation is usually done based on the floor area. To estimate each type of waste amount, a widespread criterion is 20 cm tall mixed waste per m2 built, according to use, with a standard density from 0.50 t/m3 to 1.50 t/m3. In order to obtain the weight by waste type, data based on studies about the composition of the CDW going to landfill could be used.

Summarizing, research in this field has focused in two ways: “hard” methods, measuring waste produced directly on site or through the weight of the trucks leaving the work, and “soft” methods, through questionnaires, interviews and surveys of experts and workers. When dealing with waste generation rates forecast, two approaches have been found. First is sorting waste into different categories, e.g. those established by the EWC. The second is managing waste as a whole and estimating the total volume.

A realistic approach to the problem undertakes to manage the project as a large number of interrelated and different task types (project units), in which each of these works affects differently in waste generation. Similarly, if forecasting models are developed based only on available historical data, without the necessary preliminary analysis and processing, a significant error could be introduced, as this information can come from heterogeneous and unevaluated sources.

Thus, analysis and thorough evaluation of all available information, complemented with expert information, is mandatory. Construction sector should incorporate these sustainability criteria, which will contribute to a better separation of waste in future C&D projects, a greater waste reuse and recycling degree, and therefore a reduced environmental impact.