Jargon Buster

Simple definitions that explain any specialised words and phrases you might be unfamiliar with – all clarified in plain language.


Search:





(clear)

Category: All categories air pollution allowing heavier loads) relative to the level of network outputs funded at the last relevant periodic review. Usually Blacklist who:-prepares or modifies a design













  • a


  • A sequence of adaptation investments or policy actions that work together to achieve resilience over time, efficiently and affordably. Adaptation pathways supports strategic, flexible and structured decision-making. It allows decision makers to plan for, prioritise and stagger investment in adaptation options - with trigger points and thresholds to identify when to revisit decisions or actions.

  • The ability to adapt to the changing climate by embedding resilience and adaptation into everything we do. This improves understanding and management of climate change within our organisation and/or the industry as a whole.

  • An ‘adverse’ weather day is when the public would expect normal service to be maintained during poor weather (e.g. frost/light snow, warm or windy days) yet the conditions impact reliability and cause delays.

  • As Low As Reasonably Practicable - Reasonably practicable involves weighing the risk/benefit against the effort, time and money needed to control it. Any requirements within this standard should be applied to ALARP using a whole-life cost approach for their consideration. 

  • Any item, entity, or property owned by Network Rail and regarded as having actual or potential value or function to the operation of the rail network, to other Network Rail business activities, or to other stakeholders. 

  • b


  • Biodiversity Action Plan

  • British Agrochemicals Standards Inspection Scheme - BASIS is a UK professional certification and regulatory body that sets training and competency standards for people involved in the sale, supply, and advice of pesticides, herbicides, fertilisers, and related agricultural products.

  • The variety of plant and animal life in a particular habitat – from tiny insects to 100-year-old trees. This includes terrestrial, marine, and other aquatic ecosystems and the ecological complexes they are part of.


  • A policy approach that aims to counter the negative impacts of development projects on the environment by using environmental mitigation measures.

  • Biodiversity Net Gain - An approach (usually in the context of development) to works which makes sure that habitats for wildlife are left in a better state than before development. In Wales, this approach is referred to as ‘Net Benefit for Biodiversity.’ In Scotland, the term applied is ‘positive impact on biodiversity’.

  • Best Practicable Means - BPM is defined in Section 72 of the Control of Pollution Act as “reasonably practicable for the local conditions and circumstances, using measures including good design, good practice installation, maintenance, manner and periods of operation of plant and machinery, acoustic structures and the financial implications of each.

  • Building Research Establishment Environmental Assessment Method - An international scheme that provides third-party certification for the assessment of sustainability performance for projects, infrastructure and buildings.
  • Biodiversity Units are the primary means for measuring changes in biodiversity value on a given site. They quantify the ecological worth of habitats based on their condition, area, and distinctiveness, as well as strategic significance. This measurement is achieved through the Biodiversity Metric, developed by Natural England, which standardises the calculation process.

  • c

  • The greenhouse gas emissions associated with the creation, refurbishment and end of life treatment of an asset.
  • The circular economy is a system where products, materials and assets never become waste and a circular flow of resources is maintained. This means enabling recovery, repair, reuse, cascading uses, or fully closed loops (e.g. remaking a product back into the same product with no waste) for technical or biological resources.

    This approach extracts the maximum environmental, social, and financial value, and reduces embodied carbon, water, and social impacts whilst supporting nature regeneration.

  • Contaminated Land: Applications in Real Environments is a UK not-for-profit organisation that helps the construction industry manage and reuse land in a safe and sustainable way. It provides practical guidance, training, and tools - such as the Definition of Waste Code of Practice (DoWCoP) - to support the responsible reuse of excavated materials and the remediation of contaminated sites, in line with environmental regulations.

  • The process of adjustment to current or expected climate change and its effects. Adaptation seeks to reduce risks, moderate harm, and exploit beneficial opportunities from today’s changed climate conditions, and to prepare for impacts from future changes.
  • The ability of a system and its parts to anticipate, absorb, accommodate, and rapidly recover from the impacts of adverse and extreme weather conditions and gradual or erratic changes in weather patterns due to climate change.
  • A grassroots movement that helps communities get the most from their local railway. It is the membership body for over 75 community rail partnerships and 1,300 station adoption groups.

  • An individual with the defined standards of knowledge, skills and behaviours required to successfully undertake a specific task. To attain a competency, the holder has to be assessed against these standards.
  • Any building or engineering work involving the creation, alteration, maintenance, or removal of structures. This includes site preparation, assembly or disassembly of prefabricated elements, installation of fixed services, and cleaning using high-pressure or hazardous methods. Activities related to mineral exploration or extraction are excluded. For the full definition of construction work, please refer to the Construction (Design and Management) Regulations 2015.

  • Land that has legally been defined as 'contaminated land’ where substances are causing or have the potential to cause:- significant harm to people, property or protected species- significant pollution of surface waters (e.g. lakes and rivers) or groundwater- air pollution- harm to people as a result of radioactivityLand can become contaminated with: - hazardous and/or non-hazardous materials from human activity (e.g. previous land uses, fuel spillages, fly tipping)- invasive non-native species- naturally-occurring hazardous substances like radon gas 
  • Any person or organisation (including a non-domestic client) who, carries out, manages, or controls construction work.  This can include a Network Rail business function that is contracted to complete work on behalf of another Network Rail business function.
  • Community Rail Partnerships act as a backbone for the community rail movement, engaging local groups and partners to work with the rail industry. There are 75+ partnerships across Great Britain.

  • d

  • Department for Environment and Rural Affairs - The government department responsible for environmental protection, food production and standards, agriculture, fisheries and rural communities across the United Kingdom.
  • Delegation of Authority refers to the authority that has been delegated from the Board to the ELT and from the ELT to people in specific roles, to subsidiary company boards, or to specialist committees and panels. For the Environment, this refers to the delegation of authority for signing and being held accountable for environmental permits, licences and consents.
  • Design includes any production of drawings, design details, specifications and bills of quantities (including specification of articles or substances) relating to a structure, and calculations prepared for the purpose of design.

  • Any person or organisation, including a client, contractor or other person, who:-prepares or modifies a design, -arranges for, or instructs, any person under their control to do so, relating to a structure, or a product or mechanical or electrical system intended for a particular structure. A person is deemed to prepare a design where a design is prepared by a person under their control. This can include a Network Rail business function that is contracted to complete work on behalf of another Network Rail business function.
  • Department for Transport
  • Diversity Impact Assessment - The method Network Rail uses to assess the potential impact our work has on people who share protected characteristics, whether they are an employee, passenger, or our line side neighbours.

  • The authority that has been delegated from the board to the Executive Leadership Team (ELT), then from the ELT to people in specific roles, to subsidiary company boards, or to specialist committees and panels. For the environment, this refers to the DoA for signing and being held accountable for environmental PLCs.

  • e

  • Environment Agency - A non-departmental public body, established in 1996 and sponsored by the United Kingdom government's Department for Environment, Food and Rural Affairs, with responsibilities relating to the protection and enhancement of the environment in England. It is primarily responsible for flood management, waste management, regulating land and water pollution, and conservation.

  • Under the Environmental Permitting Regulations, emergency works are when there is:-serious risk of flooding-serious detrimental impact on drainage; and/or-serious harm to the environment.The activity can not be a pre-planned activity.Emergency works as defined under the Railway Act does not align with the emergency works as defined by environmental regulators.
  • Any role within Network Rail responsible for managing and delivering the contracted project or works activity at a given stage in the project/works life cycle. For example, a contract manager, development manager, project manager, or asset manager.
  • Environment Management System - An environmental management system is a framework designed to help organisations monitor, control, and continuously improve their environmental performance.

  • Schemes to change network outputs, usually involving construction, that improve network capacity or capability (e.g. enabling higher speeds, allowing heavier loads) relative to the level of network outputs funded at the last relevant periodic review. Usually, outputs are required at specific times (in contrast to most renewals).Definition from Office of Road & Rail (ORR)Enhancement projects include:-Projects in the Rail Network Enhancement Pipeline (RNEP).-Projects listed in the Network Rail Enhancements Delivery Plan (EDP) which is updated quarterly.-Projects funded by third parties (not DfT or Transport Scotland) but delivered by a Network Rail enhancements team.-Any additional transport construction or engineering enhancement projects/programmes which require submission of formal business cases to national government agencies to secure funding approval before the project/programme is authorised to proceed.
  • Environment that is around us, which includes both living and non-living things such as soil, water, animals and plants.
  • Close calls are events that could have caused harm but did not, and reporting these helps prevent future incidents e.g. incorrect storage of fuels and oils.
  • An Environmental Incident is defined as a specific unplanned event or occurrence that has an environmental impact and may require an immediate response in order to minimise the impact.
  • An independently verified and registered document that communicates transparent and comparable information about the life-cycle environmental impact of products. The International EPD System is a global programme for environmental declarations based on ISO 14025:2006 and EN 15804:2012.
  • Environment & Sustainability. Sustainability has three pillars - environmental, economic, and social. As many roles in Network Rail deal with environmental legal compliance, we still refer to E&S - where environmental issues are part of the wider sustainability agenda.
  • Environment and Social Appraisal. Network Rail PACE product. The ESA is a Network Rail tool owned by the Employer's Representative that enables Network Rail to collate pre-construction information on sustainability risks and opportunities.
  • Environment and Social Management Plan - provides Network Rail teams and suppliers with a formal plan to address Environment and Social Performance themes following use of the ESA. ESMPs can be presented as Design ESMPs (DESMPs) and Construction ESMPs (CESMPs).
  • An ‘extreme’ weather day is when the railway is not expected to operate without disruption and delay given the nature of the weather experienced (e.g. a storm, prolonged rainfall/flooding).

  • f

  • Forestry Commission - a non-ministerial government department responsible for the management of publicly owned forests and the regulation of both public and private forestry in England.
  • Any material derived from forestry, including timber, composite timber products, paper, card, etc.

  • g

  • Greenhouse gases - a group of gases, both natural and human-created, that can warm the atmosphere. When released into the atmosphere they will absorb and emit radiation at specific wavelengths within the spectrum of infrared radiation emitted by the Earth’s surface, the atmosphere and clouds.
  • Greener Railway Hub is a Network Rail managed website designed as a central resource for colleagues and supply chain partners. It provides easy access to key information, answers to frequently asked questions, and contact details for further support. All sustainability guidance notes, and technical manuals can be found on the Hub. Please refer to the site first for any queries or further information.

  • h

  • The HSE KPI Tool is the system that our contractors use to input safety, health and environmental data. The data is submitted periodically and used for reporting and monitoring purposes by Network Rail.  Access to the system - https://nr-hse-kpi-reporting.co.uk/
  • Health & Safety File - A file prepared to satisfy regulation 12(5) of the Construction (Design and Management) Regulations 2015. The purpose of the HSF is to confirm that, at the end of a project, the client has information that anyone carrying out subsequent construction work on the same site or structure would need to be aware of in order to plan and carry out work safely and without risk to health.

  • i

  • Indications of performance and/or the likelihood of meeting targets. The most significant of these, for a business, are key performance indicators.
  • This includes:
    - owners and operators of rail infrastructure such as Network Rail and HS1
    - organisations designing and building new infrastructure such as HS2 and East West Rail
    - Integrated Transport Authorities and Transport Authorities such as Transport for London and Transport for Wales

  • l

  • Taking materials from the Earth, making products from them, and eventually throwing them away as waste.

  • m

  • Activities that allow us to keep an asset in use, or restore it, so it can keep performing its required function.
  • Marine Management Organisation - an executive non-departmental public body of the Department for Environment, Food and Rural Affairs. They license and regulate marine activities in the seas around England and Wales so that they're carried out in a sustainable way.

  • n

  • An executive non-departmental public body, sponsored by the Department for Environment, Food & Rural Affairs.It is responsible for ensuring that England's natural environment, including its land, flora and fauna, freshwater and marine environments, geology and soils, are protected and enhanced. It also has a responsibility to help people enjoy, understand and access the natural environment.
  • An executive non-departmental public body of the Scottish Government responsible for Scotland’s natural heritage, especially its natural, genetic and scenic diversity. It advises the Scottish Government on nature conservation, and acts as a government agent in the delivery of conservation designations, i.e. national nature reserves, local nature reserves, national parks, Sites of Special Scientific Interest (SSSIs), Special Areas of Conservation, Special Protection Areas and the national scenic areas.
  • Nature-based Solution The development and use of nature (biodiversity) and natural processes to address diverse socio-environmental issues.

    These issues include climate change mitigation and adaptation, human security issues such as water security and food security, and disaster risk reduction.

    The aim is that resilient ecosystems (whether natural, managed, or newly created) provide solutions for the benefit of both societies and biodiversity.

  • Greenhouse gases, generated by human activity like burning fossil fuels, contribute to global warming. These greenhouse gases are commonly referred to as carbon emissions. Achieving ‘net zero’ carbon means getting a balance between the emissions we create and those we eliminate or offset for example, through planting trees.
  • No Net Loss (of Biodiversity) - an environmental policy approach that aims to counterbalance the negative impacts of development projects on the environment by using environmental mitigation measures.

  • An environmental policy approach that aims to counterbalance the negative impacts of development projects on the environment by using environmental mitigation measures.
  • Works outside the scope of construction works might include non-intrusive surveys and inspections carried out as part of the pre-construction phase, vegetation clearance that is not associated with the construction phase, and structures examinations.
  • Natural Resources Wales - is a Welsh Government sponsored body responsible for the sustainable management of natural resources in Wales, focusing on environmental protection and regulation.

  • o

  • Office for Environmental Protection - is a public body that protects and improves the environment by holding government and other public authorities to account.
  • Building resilience into specific assets or systems leading to a measurable improvement in performance and safety ‘on the ground’. For example a flood alleviation scheme at a junction which experiences frequent disruption; replacement of old overhead line equipment, installation of back-up power supplies or air conditioning on trains. This is in contrast to resilience improvements achieved through enhancements in adaptive capacity.

  • p

  • Project Acceleration in a Controlled Environment - describes how Network Rail manages and controls investment projects on the rail network. Network Rail has developed this approach to managing projects in order to minimise and mitigate the risks associated with project development and delivery.
  • Polychlorinated Biphenyl PCBs are a group of man-made, toxic chemicals with a range of physical properties, including oily liquids or waxy solids. This made them very effective as dielectrics and coolant fluids in electrical apparatus such as transformers and other types of electrical equipment. However, it was later discovered that PCBs are toxic to human health and harmful to the environment and they have since been banned.

  • Group term for equipment with a fluid (oil) containing total mixture of PCBs > 50ppm and a total fluid (oil) volume ≤ 5 litres, or Equipment manufactured prior to 1987 containing or assumed to be containing a fluid (oil) volume > 5 liters with unconfirmed PCB content.Total mixture means the total amount of all types of PCB structures that might be present in the oil.PCB Contaminated Equipment is required to be registered with the relevant Environmental Regulator.
  • Preliminary Ecological Appraisal - a rapid assessment of the habitats and ecological features, present or potentially present, within a site and within the wider zone of influence of a project or work site. A PEA normally comprises a desktop study and a site walkover survey such as an Extended Phase 1 Habitat Survey. The PEA will determine the need for further Phase 2 surveys. PEAs need to be conducted in accordance with the most current edition of Chartered Institute of Ecology and Environmental Management (CIEEM) Guidelines for Preliminary Ecological Appraisal.
  • Environmental Permit, License or Consent - these are required to support Network Rail and its supply chain to meeting its compliance obligations under current UK legislation.
  • A pollution pathway is the route by which a contaminant (pollutant) travels from a source to a receptor, such as humans, watercourses, or wildlife. It includes all environmental media or mechanisms (e.g. air, soil, water, groundwater) through which the pollutant can move. Pollution pathways are a key component in assessing environmental risk and are sometimes also referred to as pollution linkages.
  • Water that is safe to drink.
  • The Preliminary Risk Assessment (Contaminated Land, Phase 1 desktop study) is the first stage of the contaminated land assessment process. This involves analysing historical and environmental information for the site and within a 250m radius around the site as detailed in the Environment Agency’s Land Contamination Risk Management (LCRM) guidance. A risk assessment report with conceptual site modelling will be undertaken. If this demonstrates no risk from contamination, the planning will be released, subject to local authority agreement.

  • r

  • A chart that shows who is Responsible, Accountable, Consulted, and Informed for each task in a project.
  • Where waste is used to replace other materials, for example when waste is used to produce energy.
  • Where waste products are reprocessed into new products, materials or substances.
  • Major capital works or replacement of the network in order to maintain its required capability. These may be required at specific times but are more often carried out according to Network Rail's own timetable. Definition from Office of Road & Rail (ORR).
  • The ability of assets, networks and systems to anticipate, absorb, accommodate, and rapidly recover from the impacts of adverse and extreme weather conditions and gradual or erratic changes in weather patterns due to climate change.
  • Reuse is when original products or materials are used for the same purpose for which it was designed.
  • Rail Social Value Tool A web-based tool used to record social value impacts on projects and schemes. RSVT is free to access for all Network Rail employees and suppliers working on our projects.

  • s

  • Emissions that arise directly from the fuel we burn as a company.
  • Emissions from the power used in our assets.
  • Carbon emissions associated with our suppliers who provide us with goods and services, as well as those generated through activities by train and freight operating companies.
  • Sustainable Development Goals - a collection of 17 global objectives established by the United Nations in 2015 as part of the 2030 Agenda for Sustainable Development.
  • The Scottish Environment Protection Agency - is Scotland's environmental regulator and national flood forecasting, flood warning and strategic flood risk management authority. Its main role is to protect and improve Scotland's environment. SEPA does this by helping business and industry to understand their environmental responsibilities, enabling customers to comply with legislation and good practice and to realise the economic benefits of good environmental practice.
  • An environmental assessment method, benchmark and standard for non-domestic fitouts, led and owned by the Royal Institute of Chartered Surveyors (RICS).
  • Sustainable Land Use - is the practice of managing land resources in a way that meets current needs without compromising future generations.
  • The extent to which Network Rail's operations, activities and decisions impact people - including passengers, employees, suppliers, communities or other groups affected by Network Rail's physical and socio-economic presence.

  • Social sustainability focuses on how businesses impact people - positively and negatively. It involves proactively addressing impacts and relationships with stakeholders such as employees, supply chain, customers, and local communities.  

  • The UK faces economic and social challenges, made worse by the cost-of-living crisis, social value is about adding benefits that aid the recovery of our local communities, for example, through employment, re-training or supporting local businesses. The term 'social value' is sometimes used interchangeably with the term 'social performance’.

  • a) Any building, timber, masonry, metal or reinforced concrete structure, railway line or siding, tramway line, dock, harbour, inland navigation, tunnel, shaft, bridge, viaduct, waterworks, reservoir, pipe or pipeline, cable, aqueduct, sewer, sewage works, gasholder, road, airfield, sea defence works, river works, drainage works, earthworks, lagoon, dam, wall, caisson, mast, tower, pylon, underground tank, earth retaining structure or structure designed to preserve or alter any natural feature, and fixed plant; or similar, b) Any formwork, falsework, scaffold or other structure designed or used to provide support or means of access during construction work.
  • The term used within Network Rail contracting to refer to a Designer and/or Contractor.
  • A Network Rail interal mobile app that connects consumers with local stores offering surplus, imperfect, or overstocked goods at discounted prices, promoting sustainability and reducing waste.
  • Meeting the needs of the present without compromising the ability of future generations to meet their own needs.

  • t

  • The energy used to move trains.

  • u


  • Union Internationale de Chemin de fer - International Railway Union (based in Paris).
  • Also known as non-emergency unplanned works. Works that were not planned but have to be undertaken urgently when a rail asset has failed due to a sudden and unforeseen event, fault or defect. There is not involvement from emergency services, but the work is deemed urgent in order to restore the rail network to a safe operating condition.

  • w

  • The ability of assets, networks and systems to anticipate, absorb, adapt to, and/or recover from disruptive weather events.
  • The sum of all asset-related carbon and other GHG emissions and removals over the life cycle of an asset, including its design, construction, operation, maintenance/repair and disposal.
  • The Waste and Resources Action Programme - is a UK-based registered charity that works with governments, businesses, and communities to accelerate the transition to a circular economy. Its mission is to reduce waste, promote sustainable product design, and improve resource efficiency across sectors including food, textiles, and plastics.

Latest Updates

Latest Case Studies

Latest Environment Bulletins