3. Notes on the analysis and evaluation of environmental impacts

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3.1 Limits and guidelines in Germany and other industrialised countries

Existing quality standards in the Federal Republic of Germany, in the member states of the European Community (EC) and in other industrialised countries are mainly focussed on the question of supply with satisfactory drinking water. In the main, these standards lay down limits or guideline or maximum values for constituent concentrations and bacterial counts which must be observed for certain uses in order to rule out risks to the health of humans. Consequently, the environmental relevance of these standards lies chiefly in their aim of preventing repercussions on health and hygiene from an unsatisfactory supply.

In the Federal Republic of Germany, drinking water supply is governed by the standards and guideline values in the Trinkwasser-Verordnung (TVO - drinking water regulations), but these cover only the most important types of substances (of the 650 or more that have so far been classified as hazardous to water). In addition to this, there are generally sectoral codes in the Federal Republic of Germany for assessing and, where applicable, preventing impacts generated by water supply on environmental resources. For historical reasons, the Republic has a federal structure and because of this structure it is possible that the implementing regulations in particular may be different in different federal states. For this reason alone, there may be major problems in transferring standards to other countries.

The most important sectoral statutory instruments are concerned with water management (the "Wasserhaushaltsgesetz" (Federal Water Act) and the water laws of the individual federal states), and nature conservation and care of the landscape (Landespflege und Naturschutzgesetze). However, the sectoral division means that other statutory instruments, such as mining law, may also have an indirect bearing on the question of limiting environmental impacts generated by water supply.

The most important guidelines relating to the setting up of supply wells are concerned with the laying down of so-called water protection areas.

The areas are divided into three hazard zones and in them restrictions on use are laid down. The aims of these restrictions are as follows:

(1) to prevent pollutants from entering the soil and groundwater in the vicinity of wells.

(2) to ensure that pollutants are properly degraded as they pass through the soil and are carried into the groundwater (the 50-day line).

(3) to ensure that if accidents occur outside the protection zones, enough time is available for countermeasures to be implemented.

The implementing provisions that apply in the Federal Republic of Germany (e.g. DIN standards) help to ensure that, for example, there is no uncontrolled entry of pollutants into the groundwater when wells are being sunk and, by providing authoritative directions for assessment and analysis, that decisions likely to create environmental stress are not made later on.

Guidelines and standards from other industrialised countries are, on the whole, intended to achieve similar objectives to those in the Federal Republic of Germany.

However, depending on the intensity of use and the historical background, laws and regulations in given countries may be very different, especially with regard to the precise values laid down and the number of quality requirements specified for drinking water. In the EC, there have already been some initial successes in harmonising the drinking water standards of the member states.

3.2 Other national guidelines

Specific laws and guidelines applicable to the environmental impacts of water supply are as yet unknown in many countries.

In some regions there are traditional codes relating to the abstraction and distribution of water that govern matters such as:

- the use of water from springs,
- the limits set for the withdrawal of water from wells and well fields,
- recharging of groundwater
- use of suitable wastewater for irrigation,
- management of the water from impoundments,
- distribution of surface water for irrigation,

These may very well be important for environmental protection and an endeavour should be made to take them into account on appropriate projects.

However, it should be remembered that there is often only an inadequate foundation for:

- water budgets,
- forecasts of multi-sectoral water requirements,
- forecasts of future water quality,
- priority needed to be given to the allocation of water resources for human use,
- statutory water regulations,

due to a lack of basic data.

Internationally, it is chiefly the World Health Organisation (WHO) International Standards for Drinking Water that serve as a main reference tool. However, it should be remembered when carrying out projects in countries where conditions are extreme that the WHO standards are only recommendations and that exceptions may be allowed in cases where there are good grounds for doing so. Over past years greater importance has been attached to the WHO's minimum hygiene requirements (bacterial counts, pathogens) than to the maximum concentrations of water constituents.

It is often the case that, although broad guidelines and regulations may already have been laid down at national level, there are no mechanisms or resources for implementing them.

3.3 Rating of environmental impacts

For rating environmental impacts, there are different priorities that may be adopted at the outset. In countries where there is already a scarcity of water resources, overriding priority may be given to assessing how much water will be available in the medium and long term. Where water resources are adequate in terms of quantity, then priority in evaluating the environmental impacts of urban water supply will be given to the hygiene and compatibility with good health of the water distributed for human consumption, bearing in mind that if the resource is not adequately safeguarded for the future or is not adequately protected, this may jeopardise the urban water supply's long-term benefit to those supplied.

A very negative view should be taken of uncontrolled and wasteful use of water, e.g. where, in an arid region, the private growing of wheat by irrigation is allowed to take precedence over long-term use of scarce groundwater resources for general human consumption.

2.6 Environmental protection measures and recommended options.

4. Interaction with other sectors

Projects in the urban water supply sector have a multiplicity of interactions with other sectors; the most important of these occur where there are:

a) competing uses for the water resource (urban water supply, irrigation, consumption by trade and industry, power generation) or other stress-creating demands on it,

b) activities that may pose a threat of pollution to the water resource (use of fertilisers and pesticides, incorrect storage of refuse and trade and industry waste, pollutant-charged precipitation caused by emissions, non-secure transport of pollutants),

c) plans, and their physical results, that make it necessary for the waste water disposal system to be improved,

d) planning that causes interference with groundwater recharge (impoundment or diversion of surface waters, changes to vegetation, drainage operations, building).

Table 1 is an overview of the sectors that interact with urban water supply and contains cross-references to other environmental briefs that are of crucial importance for evaluating consequential impacts.

The urban water supply system is a essential part of any overall town-planning scheme. The best opportunity for avoiding consequential environmental impacts therefore lies in balanced planning for urban development with due consideration for regional planning and for water framework planning. This is particularly true of the interactions between urban water supply and water disposal and the rule that should be followed in practice is that supply with drinking water and discharge of waste water should be planned together to rule out the possibility of overloading. It is only in the last few years that the later consequences of incorrect waste disposal, and particularly the disposal of industrial waste, to urban water supplies have been realised in the industrialised countries. Given the industrial development that is going on in many countries, it is clear that consideration also needs to be given to choice of location and waste water disposal when urban water supply projects are in prospect.

Table 1 - Environmental impacts from related sectors

5. Summary assessment of environmental relevance

Generally speaking, it will not be possible to assess the severity of the impacts created by urban water supply systems by following a standard, fixed procedure and it will be more a matter of weighing the good intention of developing a life-preserving resource against the related consequences of interfering with the ecological equilibrium that will follow under the laws of nature. Those responsible for the project also need to be aware of the fact that drinking water performs the role of a pacemaker, in the widest sense of the word, for sociocultural and socioeconomic conditions and care therefore needs to be exercised in bringing it into play as a contributory factor to structural improvement.

An assessment of the environmental relevance of urban water supply can be undertaken by considering the following questions:

- the appraised water resources, and multi-sectoral use,
- evidence for efficient water use in present and planned urban water supply systems combined with efficient disposal,
- planning considerations of significance for environment-orientated urban water supply projects.

5.1 Appraised water resources, and multi-sectoral use

- Evaluation of the current availability and quality of water resources in the light of multi-sectoral use and seasonal variations in availability, quality and use.
- Reliable appraisal of the future availability and quality of water resources and reliable monitoring of their present availability and quality (constant measurement, hydrogeological, hydrological, chemical, physical and biological checks, and professional analyses and appraisals).

5.2 Evidence for efficient water use in existing or planned urban water supply systems coupled with efficient disposal

- Constant monitoring of the use of water resources by the body operating the urban water supply system in collaboration with other water resource users.
- Consumption monitoring, control of consumption (during dry periods), monitoring of water losses, and quality monitoring of the water supplied from the urban water supply system.
- Evidence of the need for rehabilitation work to be done on the urban water supply system, and particularly on the water distribution system, classified by priority.
- Efficient implementation of statutory codes and regulations,
- Efficient disposal and disposal monitoring,
- Effective provisions for improving the availability of water resources by means of artificial infiltration, retention basins, dams.
- Efficient re-use of cleaned water.

5.3 Curative measures for inefficient water use in existing urban water supply schemes and inefficient disposal

Curative measures may need to be applied to one or more of the items listed in 5.2

5.4 Important planning considerations for environment-orientated urban water supply projects

There is no fundamental reason why urban water supply systems should not be planned and constructed in an environment-orientated way. However, for this to be the case, there are a number of preconditions that have to be met which, in particular cases, may sometimes entail severe restrictions on water consumption.

The planning of environment-orientated urban water supply projects will call for:

- the environmental impacts of planned urban water supply systems to be checked for improvements, amendments and extensions likely to affect the acceptability of a project and the considered need for and benefits from it, against the background of country-specific value systems. (Simple unquestioning adoption of standards from the industrialised countries may lead to major planning errors.)
- an attitude of problem-awareness directed to regional conditions to be created among project planners and population in connection with the environmental implications of water consumption. (Policies restrictive of consumption in areas short of water and areas at risk ecologically, the importance of introducing cost-covering tariffs, the implementation of statutory codes and regulations).
- careful on-site investigation of conditions, such as what the requirement is, water availability and quality, the regenerative capacity of the resource, the risk of pollutant intrusion, and impacts of water abstraction on the ecology, with the services of specialist multi-disciplinary bodies being called upon to deal with particularly involved questions (depletion of water resources, consequences of water table lowering).

These on-site investigations must also cover the condition of existing systems and an assessment of existing shortcomings and obvious errors in the techniques employed likely to have repercussions on the improvement of the existing systems and practices.

The local investigations should pay particular attention to socio-economic questions, such as family income, income of women, stress on women caused by transporting water, attitude of the population to the scarcity and importance of water as a resource, willingness to pay, and other questions such as the willingness of the population to assist in keeping a watch on the efficient use and distribution of water and to play some part in repair work.

- assistance with the setting up of indigenous monitoring bodies to ensure that the requisite environmental precautions specific to the project are taken.

6. References

Albert, G.: Ökologische Prognosen in Grundwassergewinnungsgebieten,lecture,4.DVWK-Fortbildungslehrgang Nutzbares Grundwasserdargebot, 11 to 14 October 1982.

BMI-Fachausschuß-Wasserversorgung und Uferfiltrat: Künstliche Grundwasser-anreicherung, 1984.

DVGW-Regelwerk: Richtlinien für Trinkwasserschutzgebiete, W101: Schutz-gebiete für Grundwasser, W102: Schutzgebiete für Trinkwassertalsperren, W103: Schutzgebiete für Seen, ZfGW-Verlag, Frankfurt 1975.

DVWK (Deutscher Verband für Wasserwirtschaft und Kulturbau) - Fachausschuß Grundwassernutzung: Ermittlung des nutzbaren Grundwasserdargebotes DVWK-Schriften H. 58, 2 Teilbände, 1982

Environmental Protection Agency: National Interim Primary Drinking Water Regulations, July 1st 1983.

Gesetz zur Ordnung des Wasserhaushalts: (Wasserhaushaltsgesetz, WHG) of 16.10.1976 and Wassergesetze der Länder.

Ministerium für Ernährung, Landwirtschaft und Umwelt Baden-Württemberg, "Leitfaden für die Beurteilung und Behandlung von Grundwasserverun- reinigungen durch leichtflüchtige Kohlenwasserstoffe", Stuttgart, 1983.

EC Council directive on quality required of surface waters intended for the abstraction of drinking water in the Member States of 16 June 1975

EC Council directive on quality of water intended for human consumption of 15 July 1980

EC Council directive on the protection of groundwater against pollution caused by certain dangerous substances

Umweltbundesamt (German Federal Environmental Agency): Synopse nationaler und internationaler Gewässerschutzregelungen, April 1979.

Verordnung über Trinkwasser und über Brauchwasser für Lebensmittelbetriebe (Trinkwasser-Verordnung) of 31.10.1975.

WHO-World Health Organization: International Standards for Drinking Water, Geneva, new edition (1984).

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