Water Pollution: Tackling the Issue of Eutrophication
Water Pollution: Tackling the Issue of Eutrophication.
Brian Jack
Introduction.
Eutrophication is an environmental problem that affects water bodies in both the Republic of Ireland and Northern Ireland. In the Republic of Ireland, the Environmental Protection Agency has reported that:
“Eutrophication, or nutrient enrichment, is the principal threat to water quality in Irish lakes.”[1]
Similarly in Northern Ireland, a recent consultation paper noted that:
“Northern Ireland faces a series of water quality problems affecting rivers and lakes and extending into marine waters. The largest and most widespread of these is nutrient enrichment arising from too much nitrogen, largely in the form of nitrate, and phosphorous entering the water. This causes an undesirable disturbance to the water’s ecology resulting in a phenomenon known as eutrophication.”[2]
However, eutrophication is not merely an environmental problem within Ireland; it is also a problem that has occurred throughout the European Union. For example the European Environment Agency has stated that:
“The main problems affecting the ecological quality of European lakes and reservoirs are acidification due to atmospheric deposition and increased levels of nutrients, causing eutrophication.”[3]
This paper will examine the position that measures to counter eutrophication adopt within the European Union’s broader environmental policy. The paper is divided into three sections. Section one examines the concept of eutrophication, its causes and also its prevalence in Ireland. Section two sets out the legislative framework that the European Union has adopted in order to tackle this environmental issue. Finally, Section three then considers a number of recent decisions of the European Court of Justice in relation to eutrophication and examines their implications for Irish Environmental Law.
1. Eutrophication as an Environmental Issue.
The principal source of water pollution in Ireland is organic, biodegradable material derived from domestic sewage, industrial sites and run- off from agricultural and urban land surfaces.[4] One of the consequences of such pollution is that it carries a number of nutrients, mainly nitrogen and phosphorous, into Ireland’s waterways. These nutrients already occur naturally in rivers and lakes, at background levels. However, the effect of pollution, in introducing enhanced nutrient levels, can be to cause eutrophication.
Eutrophication occurs as a result of a process through which the higher nutrient levels stimulate the growth of aquatic plants, especially algae, on the surface of still or slow moving water bodies.[5] This growth can particularly affect lakes and coastal areas such as estuaries. The impact of eutrophication in these areas can be measured both in ecological terms and also, in anthropocentric terms, in relation to its effect upon us.
In ecological terms, algal growth on the water’s surface limits sunlight penetration. Equally, photosynthesis by the algae also causes a reduction in the oxygen levels of affected waters. The level of de-oxygenisation is also increased by microbial action upon dead algae on the floor of the lake or estuary. Ultimately, these limitations in the available levels of sunlight and oxygen will reduce the diversity of plant and fish life that the affected waters can sustain.[6] This equally has an impact upon the potential use of these waters for recreational uses such as angling. At the same time, it should also be recognised that some of the algae associated with eutrophication are known to produce toxins that are harmful to humans and animals.[7] Humans can become exposed to these toxins through the consumption of contaminated waters, through direct contact with algae in the water or through an accumulation of the toxins within sea food. Depending upon the toxins in question, the symptoms experienced by humans can vary between fatigue, diarrhoea and vomiting.[8]
Researchers have sought to identify the principal sources of the nitrogen and phosphorous loads carried within our waterways. A report published by the European Environment Agency has stated that between 46 and 87% of the nitrogen load carried by inland waters in central and Western Europe is derived from agriculture.[9] This report also noted that in some catchments point sources, predominantly domestic sewage treatment plants, were also responsible for between 35 and 43% of this nitrogen load. Contrastingly, in relation to phosphorous, the report noted that within more densely populated areas 50 to 76% of the phosphorous load within inland waters derived principally from domestic sewage treatment plants, whilst agriculture was responsible for between 20-40 %.[10] In Ireland it has been estimated that phosphorous from agricultural sources is responsible for over 70% of the total pollution load carried by freshwaters.[11]
Eutrophication in Ireland’s Lakes and Coastal Waters.
In 2002 the Environmental Protection Agency reported that water quality had been surveyed in 304 lakes throughout Ireland in the period 1998-2000.[12] 260 of these lakes (85%) were found to have low or moderate algal growth, which was consistent with them suffering little of no pollution.[13] The remaining 44 lakes (15%) were, however, found to be suffering from eutrophication.[14]
The Environmental Protection Agency has also examined the quality of Ireland’s coastal waters. Between 1995 and 1999 the Environmental Protection Agency conducted a comprehensive survey of Ireland’s most important estuaries, bays and inshore coastal waters.[15] This survey classified 13 waters as being eutrophic.[16] It also identified four additional waters as being potentially eutrophic.[17]
2. Tackling Eutrophication: The European Community’s Legislative Framework.
The European Community has set out to directly tackle the problem of eutrophication through three directives:[18]
· Directive 91/676 concerning the protection of waters against pollution caused by nitrates from agricultural sources. OJ [1991] L375/1
· Directive 91/271 concerning urban waste water treatment. OJ [1991] L271/40
· Directive 2000/60 Establishing a Framework for Community Action in the Field of Water Policy. OJ [2000] L327/1
The Nitrates Directive.
The Nitrates Directive requires Member States to identify waters that are affected by ‘pollution’. Under Article 3(1) and Annex 1 of the directive, polluted waters are defined in terms of their nitrate concentration and also in terms of their eutrophic state. Member States are required to identify as polluted any surface freshwaters and groundwaters that have a nitrate content of more than 50 mg/l or which could develop such a nitrate concentration if preventative action is not taken. Additionally Article 3(1) and Annex 1 also require Member States to identify as polluted waters “any natural freshwater lakes, other freshwater bodies, estuaries, coastal waters and marine waters” that are eutrophic or which may in the near future become eutrophic if preventative action is not taken.
Once such polluted waters have been identified, Member States are then required to designate all lands which drain into these waters as being Nitrate Vulnerable Zones.[19]
The practical impact of the identification of land as a Nitrate Vulnerable Zone is that Article 5 of the directive then requires that Member States establish an action programme in respect of this land.[20] This action programme establishes mandatory measures that farmers are required to apply, primarily in respect of fertiliser and manure use and also livestock management.[21] The objective behind each action programme being to limit the amount of nitrate, whether in the form of fertiliser or animal manure, which escapes from each farm. The Nitrates Directive additionally requires that Member States review their designation of Nitrate Vulnerable Zones at least every four years.[22] Similarly they are also required to review their action programmes every four years.[23]
The other alternative to the identification of individual Nitrate Vulnerable Zones is that Member States may decide to establish and apply action programmes throughout their national territory.[24] This is the approach which both the Republic of Ireland and Northern Ireland currently intend to adopt. Elsewhere 6 other Member States (Austria, Denmark, Finland, Germany, Luxembourg and the Netherlands) have also taken this approach.[25]
The Urban Waste Water Treatment Directive.
The Urban Waste Water Treatment Directive is designed to ensure that sewage collection systems are established for domestic and industrial waste waters and that this waste water receives appropriate treatment to reduce its environmental impact before being released into our waterways.
The directive currently requires that sewage collections systems should be in place for all settlements with populations of more than 15,000.[26] From 31st December 2005 this obligation will apply to settlements of more than 2,000.[27] The Directive then also goes on to introduce obligations for Member States to ensure that this sewage is treated before being discharged into waterways. At the moment waste water discharges from settlements with populations of more than 15,000 must undergo a process of secondary treatment, which accords with the requirements of the directive, before being discharged.[28] From 31st December 2005 these requirements concerning secondary treatment will apply to all sewage discharges from settlements of more than 10,000.[29] Additionally, from that date, the directive will also institute this same requirement in respect of all discharges of waste waters into freshwaters or estuaries from settlements of 2,000 or more people.[30]
Domestic sewage is an important source of nutrients such as nitrogen and phosphates. The Urban Waste Water Directive has therefore sought to put additional measures in place to guard against the danger of eutrophication. The directive requires Member States to identify as ‘sensitive areas’ all:
“natural freshwater lakes, other freshwater bodies, estuaries and coastal waters which are found to be eutrophic or which in the near future may become eutrophic if protective action is not taken.”[31]
This process of identification was initially required to be completed by 31st December 1993.[32] The identification of sensitive waters must also be renewed at least every subsequent four years.[33] The practical impact of the identification of a particular waterway as being a ‘sensitive area’ is that Member States were then required to ensure that, by December 1998, waste water discharges from settlements with populations of more than 10,000 underwent even more stringent treatment prior to their release.[34] This applied to both discharges that went directly into the ‘sensitive waters’ themselves and also discharges into their catchment areas. Once again the directive stipulates the parameters of the treatment that the waste water is to undergo, in this case the emphasis being on the need to radically reduce the levels of phosphorous and nitrogen carried within it.[35]
The Water Framework Directive.
This directive requires Member States to identify the individual river basins that exist within their territory and then to draw up separate river basin districts.[36] This river basin district, which for example might encompass one large river basin and several smaller basins, therefore becomes the level at which the directives environmental objectives have been pitched. Member States were then required to identify an appropriate competent authority for each river basin district that would be responsible for ensuring that the directive’s environmental objectives were being met in each river basin district.[37] In reality the directive has created three main environmental objectives for each river basin district:[38]
· The aim of achieving good surface water status by, at the latest, October 2015
· The aim of achieving good groundwater status by, at the latest, October 2015
· Achieving compliance with any standards and objectives established in European Community Law for protected areas by, at the latest, October 2015.
Within each River Basin District, the Directive’s environmental objectives will have important implications for the control of eutrophication. In order for surface waters to be classified as having ‘good surface water status’ the directive requires that both the ‘ecological status’ of that water body and also its ‘chemical status’ should be classified as being good.[39] Normative definitions of ‘good ecological status’ and ‘good chemical status’ are then set out in Annex 5 of the directive. These definitions cover a number of different elements of every water body’s ecological status. In relation eutrophication, for both rivers and lakes, for example, they stipulate that….
“There are slight changes in the composition and abundance of planktonic taxa compared to the type-specific communities. Such changes do not indicate any accelerated growth of algae resulting in undesirable disturbances to the balance of organisms present in the water body or to the physio-chemical quality of the water or sediment.
A slight increase in the frequency and intensity of the type-specific planktonic blooms may occur.”
The Legal Definition of Eutrophication in European Union Law.
Although there are several pieces of European Community legislation that play a role in tackling eutrophication, only two actually provide a definition of the concept. In the Nitrates Directive eutrophication has been defined in the following terms:
“ ‘eutrophication’ means the enrichment of water by nitrogen compounds, causing an accelerated growth of algae and higher forms of plant life to produce an undesirable disturbance to the balance of organisms present in the water and to the quality of the water concerned.”[40]
The Urban Waste Water Treatment Directive also provides a similar definition which differs only in relation to the nutrients that it identifies as being the root cause:[41]
“ ‘eutrophication’ means the enrichment of water by nutrients, especially compounds of nitrogen and/\or phosphorus, causing an accelerated growth of algae and higher forms of plant life to produce an undesirable disturbance to the balance of organisms present in the water and to the quality of the water concerned.”
3. The European Court of Justice’s Approach to Eutrophication.
The European Court of Justice has delivered two judgements on the correct interpretation of the legal definitions of eutrophication that are set out in the Nitrates and Urban Waste Water Treatment Directives. In Case C-258/00 European Commission v France (hereinafter ‘European Commission v France (Nitrates Directive)’) the Court examined the definition of eutrophication contained in the Nitrates Directive. More recently, in September 2004, the Court dealt with similar issues in relation to the Urban Waste Water Treatment Directive, in Case C-280/02 European Commission v France (hereinafter ‘European Commission v France (Urban Waste Water Treatment Directive’). Both of these cases were enforcement actions that the European Commission brought against France on the basis that France had failed to fully comply with its obligations under these directives. As such, these cases are therefore also important in establishing the extent of Member States’ obligations to tackle eutrophication issues. A number of legal issues concerning eutrophication were also raised in the European Court of Justice’s judgement, delivered in March 2004, in Case C-396/01 European Commission v Ireland.