The ENVIBASE-Project

Documentation / Online Handbook

Water

Description of the Problem

The territory of Rome is rich in groundwater. Due to the activity of the close volcanic area of the "Castelli Romani" (Roman Castles) there are several mineral springs. Natural springs with sparkling water are the indicators of such a variety. The hydro-geological particularity of the Roman countryside consists in the presence, usually in the deep layers and only in some areas in the surface layer, of clay soils, geologically originated in a marine environment and in the plio-pleistocenic period (complex of the marine clays). Such soils, because of their low permeability and their thickness, represent the impervious layer beyond which no groundwater exists.

The topic is important for the city of Rome because of the importance of water bodies in the landscape of the Roman countryside. For this reason, keeping a good level of quality both for groundwater and for surface water is an important task to be accomplished. On the other hand, the circulation of groundwater is threatened by great transformations in natural physiographic systems completely upset by great peripheral urban settlements. In northwestern and western areas, a great part of the soil geological structure in the Rio Galeria watershed was completely modified by quarries, changing the groundwater circulation, producing in some part dry soils, which had been previously rich in groundwater because of the action on the upper water table. This is a typical example of the negative effect of soil and land use management on water resources. On the other hand, the effects of local land use management on uses like drinkable water are limited since Rome is supplied by springs located several tens of and, in some cases, more than one hundred km from the city. The local springs contribute marginally to the supply, only for the Acqua Vergine Spring and some mineral water springs.

The groundwater quality is consistently damaged by the extensive urban development, characterised by large new districts developed without respecting regulations (average dimension of thousands of inhabitants), and by the excessive quantity of wells connecting the upper water tables, often polluted, with the deep water tables, generally non-polluted. In about 53 % of wells, coli bacteria were found, while the percentage drops to 16% for the deepest wells (more than 100 m deep). The disposal of effluent waters from these districts, made by uncontrolled septic tanks, leads to the soil pollution and the leakage in the underlying water tables. The requirements for drinkable waters are fixed by the Decree of the President of the Republic n. 236/88, which followed the European Union Directive 80/778 and which fixed a set of about sixty-two control parameters. The controls are made by a regional office which has been operating since 1979.

The surface waters shaped in geological areas in the roman countryside landscapes of great value, in some parts with large agricultural flood plains, in others with narrow gorges, and created the dense hydrographical network of the tributaries of the Tiber and Aniene Rivers.

The rivers and streams in the Roman territory have a very variable discharge. In the case of the Tiber River, this is not only due to the characteristics of the river and its watershed, but also to the dams built upstream mainly for production of hydroelectric power, to the water intakes from the river, mainly for irrigation, and from springs located in the watershed. Some of the tributary streams of the Tiber and Aniene Rivers in drought periods are completely dry, while others have a consistent discharge during all the seasons. The water intakes for different uses (agricultural, industrial, households) produced a general degradation of river ecosystems.

The hydrological network is the receptor of seventy-one public sewers, which were not previously treated by the treatment plants located in the territory of the city. The effluents brought by those sewers correspond to about 500,000 inhabitants. This fact leads to an organic pollution, characterised by the consistent presence of coli bacteria, high values of BOD, and low values of DO. Moreover, the same water bodies collect about 1316 private sewers, surveyed by the province of Rome, which is responsible for the sewers cadastre, which was instituted by the National Law 319/76, the law dealing with the control of water quality. During the surveys made by the province, a significant quantity of unauthorised sewers was detected.

The criteria for the management of water resources are fixed by the National Law 36/94, the so-called "Legge Galli," which establishes the rules to be followed to manage all stages of water use, from the water intake to the release in the rivers and streams network.

The standards for water quality controls for recreational purposes are fixed by Regulation n.22/83 released by the Ministry of Public Health (Circolare n.22/83 del Ministero della Sanità), while the standards for the preservation of fish are fixed by the Decree 132/90. Following the last regulations, monitoring campaigns started in the 90s, applying biological methods (EBI or BMPW) still in the process of experimentation by scientific organisations.

From the point of view of management of the physiographic unit represented by the river and its watershed, the main law is the National Law 183/89, which establishes the principles of planning and programming of the actions and interventions in the watershed. There are three levels of watersheds: national, inter-regional, and regional. The extension of the watersheds belonging to the first two levels is defined according to the real dimension of the watersheds, while for the third level the small watersheds are grouped to manage territorial dimensions of a given importance. For each watershed, a River Watershed Authority is instituted, which is appointed for the programming and planning activity. Tiber River Watershed is one of the six watersheds of the national level. For the Tiber, the watershed plan is going to be developed by Partial Plans (Piani Stralcio). One such plan is related to the flood plains north of Rome, which are of great importance from the point of view of the prevention of floods in the city. Such a plan establishes zoning and regulations aiming at the conservation of the natural functions of flood plains, such as spilling areas which prevent higher discharge downstream. Concerning the vulnerability of river ecosystems due to low discharges in dry periods, studies are ongoing to define criteria and methods for managing the river in such periods of minimum flow and determining a minimum standard of water quality and biological function. For the urban area, the Tor Vergata University is in charge of the study. The research is intended to find correlations between, on the one side, river morphology and stream hydrodynamics, and on the other biological characteristics and life conditions for fish, which, respectively, are represented in terms of life conditions of the biomass, biochemical properties of water, and development of fish species.

Because of the abundant resources, there is no problem of shortage of drinking water for the territory of the city of Rome. Nevertheless, it is necessary to diminish the water consumption in order to achieve the result of a sustainable use of water; in fact, in the city of Rome, the per capita/per day consumption is about 450 l, one of the highest in Europe. There is a lack of good practice of water re-use, due to the quantity of available resources; it would be better to develop it in order to solve, with this type of low-quality water, the demand for non-drinkable water, such as water for the irrigation of public gardens, for industry, for representative fountains, particularly in dry seasons typical of the Mediterranean climate.The goal for the water quality is to reach a given biological quality class and to respect the limitations established in the rules and regulations on aquatic life.

Data Sources

The management of the water cycle, for the part concerned by the uses due to human activities, is developed by a unique management entity, the ACEA (acronym for "Azienda Comunale Energia e Ambiente," that is "Municipal Public Utility for Energy and Environment). Such a company is obliged by law to make controls on drinkable water resources to be supplied and on effluents from water treatment plants, the last stage of the cycle. ACEA has been developing monitoring campaigns on Tiber River water quality since 1989, particularly with the aim of controlling the efficiency of the water treatment plants managed by themselves.

The Institution appointed to the control of surface and groundwater is the Multizone Office for the Preventative Intervention (Presidio Multizonale di Prevenzione - PMP). Since 1979, t has been engaged in a systematic monitoring of groundwater and non-systematic surveys of surface waters.

In a non-continuous and non-systematic way, surveys are made by research institutions (ENEA, Universities, National Research Council - CNR). Such surveys are aimed at specific research objectives limited in time. There is a lack of systematic knowledge about and research activities for determining the biological characteristics of water. In order to know the quality of streams, both for the water quality and the preservation of natural banks and the natural conditions of the watersheds, studies were commissioned by the city of Rome from private consulting firms, which developed a specific database and implemented software.

Concerning hydrology, the National Hydrographic and Sea Service (Servizio Idrografico e Mareografico Nazionale), Rome Section, has had data availabile since the last century and implemented a series of remote sensing stations to measure and survey rainfalls and snowfalls, temperature, hydrometric levels, wind direction, and speed. The gauge stations communicate in real time by means of radio waves with the central office, which is able to collect and manage the database. No monitoring activity on the water table depths is performed.

Methods

The surveyed data, both on surface water and groundwater quality, allow one to measure the pollution level at the survey station. The use of models of pollution compounds’ behaviour is mainly developed to know the distribution of polluting compounds along the river reaches. The use of models of pollution dispersion in rivers is developed on a experimental basis; it is not implemented for the creation of risk assessment maps.

For river water quality, a classification was used, elaborated by CNR (Research Institute on Water - Istituto di Ricerca sulle Acque), which makes an evaluation by means of six chemical and biological parameters (DO, BOD, COD, NITROGEN AMMONIA, PHOSPHORUS and COLI BACTERIA). According to the mix of values of the parameters, the range of water quality is divided into four classes.

For biological monitoring, the main method in use is the Environmental Biotic Index (EBI), which classifies the collected samples in five quality classes according to the taxa found in the samples.

For some types of pollution, such as oil losses, there is no implemented method of monitoring because the spots move much too rapidly, and there are no procedures available to analyse and evaluate the damages due to strong stress and accumulation of toxic compounds in living organisms.

Results

The water quality data surveyed by different organisations (ACEA, PMP) are managed by the "Hydrodat" Software, used by the Tiber River Watershed Authority. The hydrological data are managed by the "Marte" Software, used by the Hydrographical Service. The data surveyed in the studies developed by the city of Rome are managed with either specific or standard software (MS ACCESS) and can be partially downloaded from the internet homepage of the city of Rome:

(http://www.comune.roma.it/ustl/dipeng.html).

The province of Rome has developed a cadastre of outlets from sewers with more than 6,000 survey forms coming both from specific survey campaigns and from authorisation procedures. The cadastre is managed by a GIS (GEODIS) making use of standard DBMS (INFORMIX/ORACLE).

Degrees of vulnerability of water resources have not been defined, and at the moment, there are no implemented evaluation procedures of sustainable use, both from the point of view of the basic environmental component "water" and from the point of view of the complex component "territory - land use."

Uses

The main use of water quality data and elaborations is the river water quality control, related to quality ceiling or floors established by law. Such a control is operated by the PMP. Nevertheless, this available information is not easily accessible to citizens or even to public administrations.

Moreover, as was previously mentioned, since there are no implemented evaluation procedures, no use is made of the available information to support decision making according to sustainable development criteria.

As a possible development, the sustainable management of water resources and of the water cycle was indicated among the goals of sustainable development in the Preliminary Report of the Environmental Action Plan, the definition of which is ongoing according to the participation procedures established by the "Agenda 21," which are designed to make citizens and economic entrepreneurs informed and active in the environmental decision-making process.