Further description:-  Diffuse pollution 

Glossary Entry
Pollution from widespread activities with no one discrete source, e.g. acid rain, pesticides, urban 
run-off, etc.
Level 1: Diffuse Pollution:

Further information:


Diffuse distribution of chemical substances is ubiquitously occurring including urban spaces as well as rural regions. Industrial development has brought prosperity to millions of people, but has also left a legacy of environmental damage that continues to impact natural resources and ultimately the human well being. A wide range of man-made chemicals designed for use in industry, agriculture, pest control, consumer goods and emissions from the combustion of fossil fuels are the main sources for diffuse pollution of soils. Within the water cycle, soils act as the key zone for storage, filtration and transport of water and associated pollutants (Fig. 1). If the accumulation of pollutants exceeds the buffer capacity, then soils or sediments can become a source of diffuse pollution releasing pollutants to adjacent compartments such as groundwater and surface waters.


Diffuse inputs to soil and groundwater can be of various nature. Typical inputs resulting in soil contamination are:

·        Agricultural practices; i.e. direct input of nutrients (fertilisers) and pesticides, application of sewage sludge and manure.

·        Atmospheric deposition of exhaust gases and particles from vehicles and industry.

·        Sedimentation of diffuse particles from waste water discharges in surface waters

Major impacts of diffuse inputs to soil and groundwater are

·        Decrease of soil quality,

·        Decrease of groundwater quality due to leaching processes of nutrients, organic matter, and pesticides and other pollutants

·        Eutrophication of surface waters due to sedimentation processes.



Figure 1: The pressure of diffuse pollution on soils: polluted soils will eventually loose their important function as filter and buffer in the water cycle. Soils are the key element in the water cycle determining the quality of groundwater, surface water, and finally drinking water



Key publications

Halm, D. and Grathwohl, P. (2004): Integrating Soil and Water Protection Against Diffuse Pollution. The Parliament Magazine: 176, March 2004 (in press), Brussels. (http://www.parliamentmag.com).

Grathwohl, P. and Halm, D. (eds.) (2004): Integrated Soil and Water Protection: Risks from Diffuse Pollution (SOWA): SOWA-Report 1 (http://www.uni-tuebingen.de/sowa).

Halm, D. and Grathwohl, P. (eds.) (2003): Proceedings of the 2nd International Workshop on Groundwater Risk Assessment at Contaminated Sites (GRACOS) and Integrated Soil and Water Protection (SOWA). 2nd International GRACOS/SOWA Workshop, Tübingen, Germany 20/21.03.2003. Tübinger Geowissenschaftliche Arbeiten (TGA) C 69, 260p., ISSN 0935-4948 (http://w210.ub.uni-tuebingen.de/dbt/volltexte/2003/794/).

W. Walther, F. Reinstorff, E. Worch, and S. Wohnlich: Diffuse input of chemicals into soil & groundwater – assessment & management. Workshop, Dresden, 26 – 28 February, 266 p., Dresden



Policy and regulations

The conservation of European groundwater resources and the establishment of a common policy started decades ago and was continually revised. Recent developments are e.g. the Water Framework Directive (WFD) which defines the management of groundwater at the scale of river basins (despite of national boundaries), postulates environmental quality objectives (good chemical status) and the “no deterioration clause” and sets a clear time frame to achieve the defined objectives. A consequent product of the WFD is the so called “Groundwater Directive” which can be considered as tool to achieve the objectives of the WFD, in particular the quality criteria to achieve “good chemical status” and to prevent and limit groundwater pollution.

In contrast to groundwater conservation the need for a common European Soil Policy has only recently been perceived. As a first step in the development of an encompassing EU policy to protect soils against degradation, erosion and pollution, the Commission has published a Communication "Towards a Thematic Strategy for Soil Protection". As consequence three thematic working groups, being “soil contamination”, “soil organic matter” and “soil erosion” and two horizontal working groups being “soil monitoring” and “research” have been formed in 2003 and are currently busy to draft a successful strategy for soil protection. In the beginning of 2004 results of the working groups are expected which will form the basis for the future EU regime on soil policy.



The working group on “soil contamination” includes a specific task force on “diffuse inputs”, two major strategies have been defined as basis for further action:

·        To reduce diffuse inputs to soil to tolerable levels as far as technically and economically achievable when no clear benefit of the action resulting in inputs can be recognised.

·        To abate effects of contaminants that are added to the soils in relation to a beneficial agricultural or other activity.


Proposed future measures so far identified are:

·        To review diffuse inputs to soil in quality and quantity and to consider their effects in a broad environmental context: i.e. soil-water-air.

·        Reconsider intensification of agriculture. The proposed revision of the Common Agricultural Policy (CAP) will pave the way for a new agricultural regime in Europe. The proposal decouples agricultural subventions from production quantities (direct payments to individual farms linked to environmental services) and puts emphasis on strengthening rural areas, the production of high quality products, and conserving the environment.

·        Good agricultural practices (GAP) need to be promoted and continually improved in view of soil and water protection

·        Existing approval system for agrochemicals and pesticides need to be reviewed in a broader environmental context, in particular in view of leaching to groundwater.

·        The existing directive on biowaste recycling needs to be reviewed in view of the general decrease of organic matter in European soils.



Figure 2: EU environmental policies relating to diffuse pollution





The EU Water Framework Directive - integrated river basin management for Europe:

Directive 2000/60/EC of the European Parliament and of the Council establishing a framework for the Community action in the field of water policy.



Groundwater Directive:

 COM(2003)550, 19th September 2003: Groundwater protection against pollution under the Water Framework Directive. The European Commission adopted a proposal for a new Directive to protect groundwater



Thematic Strategy for Soil Protection:

COM (2002)179 final. Communication of the European Commission "Towards a Thematic Strategy for Soil Protection", 16 April 2002

More information on the working groups can be found at http://europa.eu.int/comm/environment/soil/


Common Agricultural Policy:

COM (2003) 640 final. Proposal for a Council Regulation adapting (EC) No 1782/2003, establishing common rules for direct support schemes under the common agricultural policy and establishing certain support schemes for farmers, Regulation (EC) No. 1786/2003 on the common organisation of the market in dried fodder, and Regulation (EC) No. 1257/1999 on support for rural development from the European Agricultural Guidance and Guarantee Fund (EAGGF) by reason of the accession of the Czech Republic, Estonia, Cyprus, Latvia, Lithuania, Hungary, Malta, Poland, Slovenia and Slovakia to the European Union.


Clean Air for Europe (CAFE):

(COM(2001)245). Clean Air for Europe (CAFE) is a programme of technical analysis and policy development which will lead to the adoption of a thematic strategy on air pollution under the Sixth Environmental Action Programme by mid 2005. The major elements of the CAFE programme are outlined in the Communication on CAFE



Landfill Directive:

Council Directive 99/31/EC of 26 April 1999 on the landfill of waste entered into force on 16.07.1999. The deadline for implementation of the legislation in the Member States was 16.07.2001.



Sewage Sludge Directive:

Directive 86/278/EEC. The Sewage Sludge seeks to encourage the use of sewage sludge in agriculture and to regulate its use in such a way as to prevent harmful effects on soil, vegetation, animals and man.



Nitrate Directive:

Report COM(2002)407. The Implementation of Council Directive 91/676/EEC concerning the Protection of Waters against Pollution caused by Nitrates from Agricultural Sources



Compost (biodegradable waste):

COM(96) 399. The management of specific waste streams represents an important element of the general EU Waste Management Strategy by helping to reduce the impact of waste on the environment, by ensuring that waste is treated in an environmentally sound manner. Action on a specific waste stream is occasioned by its volume, its hazardousness, its treatment properties and its effects on the ecosystem.


So far, biodegradable waste has been regulated in order to reduce its negative consequences on the environment (Landfill Directive 99/31/EC). The Sewage Sludge Directive 86/278/EEC, the Organic Farming Regulation (EEC) No. 2092/91 and the eco-label for soil improvers and growing media (Commission Decision 2001/688/EC) are the EU instruments relevant to this waste stream.


EU Chemical Legislation:

REACH (Registration, Evaluation and Authorisation of CHemicals):

COM 2003 0644 (03) Proposal for a REGULATION OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL concerning the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH), establishing a European Chemicals Agency and amending Directive 1999/45/EC and Regulation (EC) {on Persistent Organic Pollutants} Proposal for a DIRECTIVE OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL amending Council Directive 67/548/EEC in order to adapt it to Regulation (EC) of the European Parliament and of the Council concerning the registration, evaluation, authorisation and restriction of chemicals




Decision support / management tools

Presently, diffuse pollution of soil and water is tackled by sectorial approaches. Water or soil protection usually focus on their specific domains and do not sufficiently coordinate their efforts. The sectorial focus is also reflected in the legislative basis of these activities. Different laws relate to soil and water protection. As chemicals are cycling in the environment between different compartments, problems in one compartment often are caused by activities in another compartment. The nitrate problem in groundwater is a perfect example. Even severe overfertilisation of agricultural land does create a serious problem for soil quality. Excessive nitrate loads can be quite rapidly removed through the uptake by plants which are subsequently harvested or via leaching. In waters on the other hand, as pointed out before, nitrate is a pollutant of prime concern. Even rather low fractions of the nitrogen fluxes which are turned over in agricultural cropping systems can already cause very serious pollution if they are exported into water bodies. Problems of this kind demonstrate that a holistic, integrative approach is desperately needed. Fig. 3 shows the interconnections between the environmental compartments, animals/cattle, and humans and the pressure pathways of pollutant inputs. The arrows and especially the crosspoints of arrows indicate the problem zones for ecosystem management, which have to be tackeled together in an integrative way.



Figure 3: Pollutant fluxes into and out of soil, groundwater and surface water compartments, as well as pathways to human, animal and crop plant receptors.



Country information / Library


Germany: relevant laws / legal texts (in German): e.g. Federal Soil Protection Law, Federal Soil Protection Ordinance, Water Budget Law, Fertiliser Ordinance)




Authors: Dietrich Halm, Peter Grathwohl, Rainer Schulin




Who does what?


SOWA – Integrated Soil and water Protection: Risks from diffuse pollution




Until today, a close interaction of soil and water has not been considered in a holistic, integrative way. Scientific disciplines often still see soil and water as separate bodies and a complete understanding of the functioning of the soil and water as an integrated system is missing. A sound scientific basis, however, is the prerequisite for the mitigation of the impacts of diffuse pollution and the management of our soil and water resources. Therefore, the European Commission funds currently an interdisciplinary group of scientists (SOWA) in the current RTD Framework Programme under “Global Change and Ecosystems”. The main task of this group is to co-ordinate and structure European research work and to provide an open platform for scientists and regulators for innovative strategies in soil and water protection. The SOWA consortium meets regularly – for more information see: http://www.uni-tuebingen.de/sowa.




No Author information available