Population Equivalent (pe)

The concept of population equivalent was developed to enable the comparison of various types of sewage (municipal, household, industrial) in terms of organic pollution. Using conversion factors, an estimation is made of how many inhabitants would be required to produce (with normal domestic sewage) the same amount of pollution. By definition, one population equivalent corresponds to 60 g of BOD5 per day.

Regulatory Authority for Energy, Networks and the Environment (ARERA)

Formally independent authority established under Law 481/1995 which has the goal of promoting the development of competitive markets in the electricity and methane sectors, mainly by regulating rates, network access, market operation and protecting the interests of end users. In 2012, the ARERA was assigned functions in the area of the quality, rates and costs of integrated water services and in 2018 functions concerning waste management services.

Water and Waste Regulatory Authority (ATO)

Pursuant to Law 36/1994, the Water and Waste Regulatory Authorities define the local level of organization of integrated water services to overcome the fragmentation of management and to reach suitable sizes for the areas served.

Ammoniacal Nitrogen

The term ammoniacal nitrogen (NH4) identifies the concentration of ammonia ions in water. It provides an index of biodegradation of nitrogenous organic substances. It is expressed in mg/l.


The term biogas identifies a mixture of types of gas (mainly methane) produced by natural bacterial fermentation (in anaerobic conditions, i.e. in the absence of oxygen) of organic residues from waste.


The term BOD (biochemical oxygen demand) is used to define the amount of oxygen consumed during a specific time period (5 days for BOD5), at a given temperature, to biodegrade the organic matter present in the water via bacterial action (uptake of oxygen by micro-organisms). High biochemical oxygen demand indicates intense biodegradation of organic matter, and may highlight the presence of organic pollution. It is therefore an indirect measure of pollution levels. Its value is expressed in mg/l.


A listed financial instrument of indebtedness issued by a company. These are long-term loans: investors are guaranteed the right to annual interest payments at a fixed rate, with return of the capital on a set date.

Services Charter

A Services Charter is a document that any entity that supplies a public service uses to outline its performance standards, declaring its goals and recognizing specific rights to the public/users/consumers, and therefore to pledge to respect specific levels of quality and quantity, with the intention of monitoring and improving its supply and management methods. It was set by law 273/95, which stated that all suppliers of public services must adopt their own Services Charters on the basis of the general guidelines issued for specific sectors.

Green Certificate (GC)

GCs offer incentives to generate electricity from renewable sources. As required by law 244/07, GCs are issued by the Energy Services Manager (ESM) and concerns the production of electricity from renewable sources of the previous year or the production expected during the current year or during the following year. They represent 1 MWh of electricity. Each individual producer or importer must feed into the grid for 2012 a 7.55% share of electricity produced by renewable sources: this quota decreases linearly starting in 2013 and reaches zero in the year 2015. The requirement can also be satisfied by purchasing GCs from other parties. 


The term COD (chemical oxygen demand) identifies the amount of oxygen required for the complete oxidation of organic and inorganic compounds present in a water sample. Thus, this is an index for measuring the degree of pollution, mainly organic, in the water from substances which can be oxidized. It is expressed in mg/l.

Code of Ethics

Document setting forth for all business activities a number of principles and specifying conduct, commitments and ethical responsibilities to be put into practice by members of the Board of Directors, staff and collaborators of the company.

The Code may be described as a “Constitutional Charter” of a company, a charter of moral rights and duties that establishes the ethical and social responsibilities of all those who work within the organization.


Simultaneous production of electricity and thermal energy (in the form of steam).


Aerobic treatment (in the presence of oxygen) of biodegradable organic waste, whose final product is compost, a soil improver, which can be used in vegetable cultivation.

Social Cooperatives

Cooperatives governed by Law 381 of 8 November 1991. This law breaks these cooperatives down into two types:

– type A = cooperatives providing social, health and educational services;

– type B = cooperatives operational within the production and labour sectors which have, among their members or employees, a level of at least 30% who are differently-abled or otherwise face hardship.

Corporate Governance

The set of processes, policies, practices, laws and institutions which influence how a company is managed and controlled. Corporate Governance also covers the relations between the various players involved (stakeholders, those who have a vested interest of any type in the company).


A warning is a deed issued by the Public Administration and/or supervisory bodies in cases where, in exercising their inspection and control activities, they detect existing or possible future deviations from regulations and provisions of national and regional law: the warning sets a term by which breaches must be eliminated.

Dispatching (electricity sector)

Activities that provide instructions for the coordinated use and operation of production plants, of the transmission grid and of auxiliary services (Bersani Decree).

Dispatching (gas sector)

Activities that provide instructions for the coordinated use and operation of extraction and storage plants, the transport and distribution network and auxiliary services (Letta Decree).


EU Regulation 761/2001 which requires businesses to implement environmental management systems based on policies, programmes, procedures and objectives aimed at improving the environment, and to publish an Environmental Statement, to be validated by the Ecoaudit Committee.

Primary Energy

Primary energy is the energy potential presented by energy carriers in their natural form, for example oil, natural gas, coal, natural uranium, water and other renewable energy sources. In the majority of the cases, the primary energy must be transformed into secondary energy in electricity power stations, refineries, etc.

Enterprise Value (EV)

Expresses the overall value of a company as the sum of its market capitalization and its net financial indebtedness.
When comparing a company’s value compared to others of the same industry the Enterprise Value is in relation to economic indicators such as EBITDA and EBIT.
Higher EV/EBITDA or EV/EBIT ratios mean higher value of one company over another.

Focus Group

A surveying technique based on discussions between members of a group of persons. The main aim is to conduct an in-depth study of a specific issue in relation to given targets. Interaction between focus group members provides the basis for the surveying action.

Ethical Funds

This term is used to describe mutual investment funds whose choice of shares, bonds and government securities is inspired by ethical selection criteria. These parameters are defined as exclusion/inclusion.

Renewable Energy Sources

Renewable energy sources are: wind, solar, geothermal, wave motion, tidal, hydraulic, biomass, landfill gas, purification process residual gas and biogas. Biomass means the biodegradable part of products, waste and residues generated by farming (including vegetable and animal substances), forestry and associated industries, as well as the biodegradable part of industrial and municipal waste.

Greenhouse Gases

These gases are transparent with respect to solar radiation, and prevent the dispersion of heat from the Earth, thus leading to the overheating of the atmosphere. Over and above greenhouse gases of natural origin, the main greenhouse gases produced by mankind are carbon dioxide, methane, chlorofluorocarbons and nitrogen oxides.


The science that studies the internal energy of the Earth and its practical applications as an energy source.


Key Performance Indicators are specific indicators selected on the basis of corporate information needs They are used to carry out corporate monitoring. KPIs may be financial, production-oriented, commercial, environmental or social in nature, or may regard multiple aspects.

Mobility Management

Mobility management identifies an internal corporate department in charge of managing staff commuting.


Normal cubic metre, the volume of gas at 0 °C and 0.1 MPa.

OHSAS 18001: 2007

The OHSAS 18001 (Occupational Health & Safety Assessment Series) standard is an internationally recognized benchmark for the certification of workplace health and safety management systems.

Nitrogen Oxides

Nitrogen oxides (mainly NO and NO2), gases produced by the combustion of fossil materials. Nitrogen oxides contribute to the formation of ozone in the lower atmosphere and acid rain.

PCB (polychlorinated biphenyls)

Highly toxic organic compounds used in a wide range of applications e.g. as fluids for capacitors and transformers. When managing and disposing of them careful attention must be paid to ensure they are not released into the environment, in accordance with laws in force.


The substance resulting from water and other liquid mixtures filtering through waste.


Particulate matter of a diameter of less than 10 microns generated by a broad range of natural and man-made sources, PM10 includes a diverse variety of solid or liquid particles that tend to remain suspended in the air, due to their small size.

Heat Pump

A device capable of transferring heat from a body at a lower temperature to a body at a higher temperature, using electricity.


Legislative Decree 22/1997 defines waste as “any substance or object which the holder discards or intends or is required to discard”. This decree classifies waste based on its origin, as urban or special, and, according to the level of hazardousness, as hazardous or non-hazardous.

SA 8000

International certification standard regarding respect for human rights, respect for workers’ rights, safeguards against exploitation of minors, and guarantees with respect to workplace health and safety conditions.

Default Service

The default service is activated by the distributor responsible for the area when under certain circumstances, a customer has no supplier but is still connected to the network and can therefore continue to draw off gas. In such cases the provision of gas is assigned to a specific vendor selected by the Single Purchaser (Acquirente Unico) by means of a tendering process.


The term TSS (total suspended solids), which are the cause of the turbidity of liquids, means the total of suspended solids and filterable solids. This represents the total amount of substances present in the sample following drying, at 105 °C. Its value is expressed in mg/l.


Stakeholders are persons with vested interests. They may or may not belong to the company of which they are a stakeholder, with different interests and needs, and they may have a bearing on the decisions, conduct or success of a company.

Sustainable Development

“Sustainable development is development that meets the needs of the present without compromising the ability of future generations to meet their own needs” (Bruntland Report, World Commission for Economic Development, 1987).

District Heating

Remote distribution of heat generated by thermoelectric power stations, cogeneration plants or waste-to-energy plants using an energy carrier (hot water, superheated water, or steam).


Tonne of oil equivalent. The conventional unit of measurement of sources of energy defined as 10,000 Mcal, the amount of energy released by burning one tonne of crude oil.

Waste-to-Energy Plant

A plant that uses waste as a fuel to produce heat or energy.

Primary Treatment

Aims to remove mainly organic TSS (Total Suspended Solids) from the in-flowing liquid waste. The process can be facilitated by using special flocculants that increase the degree of aggregation of the particles and therefore their sedimentation.

Secondary Treatment

Aims to remove biodegradable organic matter and remove solids in colloidal form, non-sedimentable and, therefore, not separable by physical treatments.

Tertiary Treatment

Aims to improve purification by reducing the load of nutrients (phosphorus and nitrogen) in the secondary effluent. In some cases tertiary treatment eliminates poorly biodegradable substances that have not been eliminated by the bacterial metabolic treatment.


Machine that transforms a given kind of energy (e.g. potential energy) into mechanical energy, made available for use via a rotating shaft. The resulting energy may in turn be used for the production of other energy (e.g. by coupling an alternator to the turbine to enable the alternator to exploit the mechanical energy to produce electricity).

EN ISO 9001:2008

International technical standard for the certification of quality management systems.

EN ISO 14001: 2004

International technical standard for the certification of environmental management systems.