Defining ecological quality: The water framework challenge

The 2000 water framework Directive comprises some 70 pages of text which set out radical new requirements for water quality which remain, for the moment, largely unfathomable. The way in which water quality targets are defined in the Directive simply cannot be translated into the present UK water quality framework.

How "good ecological status" will eventually be defined was a key topic addressed at a conference hosted by the Chartered Institution of Water and Environmental Management in November. Two visions of what good ecological quality might mean were presented - one from academic ecologist Professor Brian Moss, and the other from an Environment Agency practitioner.

Ecologist's view
Professor Brian Moss of Liverpool University began with a lesson in freshwater ecology, explaining how pristine aquatic ecosystems function - "high ecological status" waters, in the Directive's language. The point is far from an academic one, because the Directive defines good ecological quality in terms of the amount of distortion or deviation from pristine, undisturbed conditions (see box ).

Professor Moss used the rivers of the remoter parts of North America as an example, making the point that truly pristine habitats were nowhere to be found in the UK.

Rivers in their undisturbed state contain low levels of nutrients like nitrogen and phosphorus of the order of 10 to 100 times less than is common in the UK. Little nutrient leaches from the surrounding land because the banks are covered in nutrient-hungry vegetation and the main energy input to the river is through autumn leaf fall from the surrounding forest.

Leaf litter is decomposed by fungi and invertebrates, the latter producing particles and faeces which in turn nourish filter-feeding river invertebrates and films of algae and diatoms which coat rocks and other surfaces. All provide food for larger invertebrates and fish.

The ecosystem shows a tight economy of nutrients and the productivity of the forest and the river are closely tied. One notable twist to the tale is that salmon, nurtured in the gravel beds of upland rivers, migrate to the sea. When they return they import marine nutrients back into the river.

The heroic struggle of salmon to spawn in the river's upper reaches inevitably ends with the fish dying and releasing nutrients back to the water, or else being caught by bears and other predators and contributing nutrients to the forest. Professor Moss told the meeting that this nutrient source could be surprisingly significant, with 25% of nitrogen in some forest trees coming from the sea via salmon.

In the river's lower reaches, the summer channel meanders across the landscape, forming areas of fast and slow moving water rich in wildlife habitats. But the channel also widens to form flood plains to accommodate the massive volume of winter rains.

Besides being rich in habitats like swamps, water meadows and ox bow lakes, the flood plain removes nutrients from the river, collects silt and allows groundwater infiltration. "It is a grave mistake to think of such a river unfortunately flooding what should be dry land from time to time," Professor Moss warned.

Sources of damage
In contrast to that pristine ideal, Professor Moss said that even upland rivers in Britain are significantly damaged by acidification, excessive penetration of sunlight increasing the water temperature, soil erosion clogging the gravel banks where fish spawn, and dams and weirs blocking the passage of migratory fish.

In the lowlands the picture is worse, with no rivers having intact floodplains since these are generally regarded as "land to be protected from water in the interests of development or agriculture". Summer channels have also been straightened to carry water more quickly to the sea.

Intensive agriculture pollutes the water with large supplies of nitrogen and phosphorus. The result is the destruction of plants and animals designed to cope with very limited nutrients and their replacement with choking mats of filamentous algae and occasional toxic blooms.

In addition, there are the subtle and unknown impacts of chemical pollutants which result from various agricultural and urban activities.

Changing the landscape
Professor Moss told the conference that maps of water quality produced by successive Environment Departments over the past 20 years showing apparent steady improvements in water quality were "a fiction".

Present systems of monitoring and managing river quality are "historical baggage", he said. They only accurately represent the solution to the largely 19th century problem of gross organic pollution and ignore much larger current problems.

Professor Moss concluded that the Directive required management of the whole catchment - including wetlands and floodplains - and not just the water-filled rivers and lakes.

Achieving good ecological status would require nutrient levels to be reduced by a factor of ten, and to achieve this he suggested that a 50% reversion of land from agriculture to semi-natural vegetation would be needed.

The changes to the landscape would be immense, with the current pattern of islands of semi-natural vegetation in an intensive agricultural or urban setting having to be transformed into a semi-natural landscape with pockets of urban development or agriculture.

The new landscape would not only protect waters from nutrient pollution, but also provide the continuity that good ecological status habitats require to be viable.

To demonstrate the point, Professor Moss cited attempts to restore clear water and plant life to a turbid, nutrient-rich Netherlands lake after it had been treated with herbicides.

Biomanipulation to increase the numbers of algae-eating water fleas proved successful in clearing the water and allowing bottom-rooting aquatic plants to return. However, the restored habitat proved so popular with local coot populations that they soon ate all the plants and the lake reverted to its former state.

The moral he drew was that good ecological quality may not be viable in small parcels. These cannot be protected by ring-fencing, and a more comprehensive approach is needed to meet the Directive's requirements.

A regulator's view
Whether Professor Moss' view of what the Directive has in store is a pipe dream or prescience remains to be seen. A contrasting and more down-to-earth view was presented to the meeting by Geoff Phillips of the Environment Agency's water framework Directive programme.

The programme consists of almost 40 staff and is expanding as the work of implementing the Directive grows. One of its task is to collaborate with other European environmental regulators on the Directive's common implementation strategy (CIS). The CIS aims to produce non-statutory guidance on the technical aspects of the Directive to aid effective and consistent implementation across the EU.

The CIS comprises ten working groups, each specialising in a particular aspect of the Directive and reporting through a strategic coordination group to a steering committee comprised of national water directors. There are also three expert advisory fora dealing with hazardous substances, groundwater and reporting.

Mr Phillips outlined the strategy for defining the ecological status of waters which focuses on defining the boundaries between high and good status and good and moderate status. The Directive requires that the boundaries should be defined by ecological criteria - not surrogates such as nutrient levels or physico-chemical parameters. In other words, good ecological status will be defined by biology and not by oxygen levels, pH, nutrients or salinity.

In practice, this is likely to mean taking a close look at certain more diverse aquatic communities. Invertebrates in rivers, for example, respond to organic enrichment and the Agency's current biological classification depends on measuring their diversity. Algal communities in lakes might be another example.

Since the Agency does not yet have a view on what good ecological quality means, Mr Philips ventured his own opinions. Taking lakes as an example, he interpreted the Directive's Annex V (see box ) to mean that good ecological quality might be defined as a state in which human impacts did not disrupt ecological processes or result in the extinction of functional groups of organisms.

In the case of increased nutrient pollution, for example, algal growth in a lake might increase and levels of organic carbon suspended in the water would therefore also increase. A consequence would be that there would be a larger anoxic area at the bottom of the lake as this organic matter decayed.

Provided these processes were slight and did not go too far, the lake could retain good status. However, excessive levels of algae would have secondary impacts such as shading out bottom-rooted plants and increasing the anoxic area in the lake bottom to such an extent that some fish species might be wiped out. In that case, the lake would cross a threshold which might be taken as the transition to moderate ecological status.

Intercalibration exercise
The task for ecologists is to be able to recognise and define these transitions in all kinds of lakes, rivers, estuaries and coastal waters across the European Union. Given the enormous variation in these waters, and the many different pressures likely to impact on their ecology, the task is far from simple.

CIS working groups are currently considering how the waters can be classified into representative types and how pressures and impacts on waters can be analysed. But the key process that will shed light on the true meaning of good ecological status is intercalibration.

The Directive requires that Member States identify waters for a pan-European intercalibration exercise in 2004. The process aims to check that definitions of high, good and moderate ecological status are consistent across national boundaries. It should ensure that, no matter what methods Member States choose to use to measure impacts, the results are robust and can be compared with those in other countries.

One of the key issues is what constitutes the high ecological status through which other categories are defined. Paul Logan, the Agency's water framework Directive policy manager, had little sympathy with the view that it should be based on some theoretical ideal.

"All of Europe is impacted and even Alaskan waters are not pristine. Do you want to create an ideal which doesn't exist? That would mean having five categories instead of four."

The intercalibration exercise, he says, will be about looking across Europe to reach a view about what high status is and where the boundary of high/good ecological status lies. High status is therefore likely to be defined by the best European habitats - which must meet ecological, physico-chemical, chemical and hydromorphological criteria.

The Agency currently holds a draft list of sites which will be submitted in 2004, along with information on the pressures affecting each water body. The sites are intended to be selected to represent the thresholds between high/good and good/moderate status.

Mr Logan explained that the rules effectively required the Agency to decide where the boundaries were before the process began. However, it would be an iterative process and the sites chosen would represent a "first stab".

The intercalibration exercise will begin in 2005, although exactly how it will operate is not yet clear. Nevertheless, by 2006 Mr Logan expects the exercise to yield a firm view of what good ecological quality actually means.

Once definitions of good ecological quality are available, work can start on monitoring waters and developing river basin management plans. These will address water quality and quantity issues on a catchment-by-catchment basis and set objectives and programmes of improvement measures to be achieved, generally on a six-year time frame. The plans are to be put out for public consultation in 2008 and completed by 2009.

A role for economics
The Directive requires good ecological status to be achieved by 2015, but also makes provision for derogations which are likely to be widely taken up. The grounds for derogation are principally that the measures required would be "disproportionately expensive", that natural conditions do not allow good status to be achieved, or that the necessary measures may only be feasible over a longer period (see box ).

How "disproportionately expense" may be defined is not explained by the Directive. But it implies that a cost-benefit assessment will be needed to set the costs in the context of the potential benefits - though cost-benefit assessment is not expressly mentioned in the text.

There are, however, many other references to economics in the Directive. Article 5 requires Member States to complete an "economic analysis of water use" in each river basin by 2004. And Article 9 requires them to take account of "the principle of recovery of the costs of water services, including environmental and resource costs."

The detail of what the economic analysis should contain comes in Annex III. The analysis should provide enough information to calculate "the economic costs of water services", to forecast the investment needed to achieve the Directive's objectives, and to judge the most cost-effective measures.

There will therefore be plenty of opportunity for the Agency to employ the expertise in costing environmental benefits that it has gained during the water industry price review process.

Professor Joe Morris of Cranfield University, who spoke on the role of economics in the Directive at the CIWEM conference, explained: "Although the Directive explicitly requires the use of cost effectiveness analysis to decide the most appropriate measures, it is likely to require the use of cost-benefit analysis. This is because the impacts of the measures are likely to have very different impacts across different sectors and across different water users."

While the emphasis on economics might be welcomed for ensuring that the measures proposed in improvement programmes are proportionate to the benefits, in fact there is no guarantee that they will be. And Member States can only delay compliance with good ecological status on economic grounds for up to 12 years.

The economic analysis, which will inform the river basin management plans, may also present a threat to abstractors and dischargers. For example, it might show that the activities of particular water users impose too great a burden on a catchment and should be curtailed in favour of more lucrative uses. In that case, the environment agencies might respond by reducing abstraction rights or tightening discharge consents.

Hazardous substances
Hazardous substances also have an impact on the definition of good ecological quality. The Directive provides for environmental quality standards (EQSs) to be set for "priority substances" by 2006. The Commission has since drawn up an initial list of 33 substances (ENDS Report 317, pp 37-38 ).

Key decisions have yet to be made on the CIS Expert Advisory Forum about how EQSs will be set. If agreement can be reached between Member States, then common standards may be adopted across the EU. Otherwise, the Directive lays down procedures for them to derive their own values.

If waters fail to meet these standards, they will not pass the threshold of good chemical quality and therefore will not achieve good ecological quality.

DEFRA has already conducted a regulatory impact assessment of the policy on priority substances (ENDS Report 324, p 43 ). It puts the cost at £1-4 billion over 30-40 years and identifies the chemical industry, particularly organochlorine, PVC and pesticide manufacturers and the power, steel and metal industries as likely to be hardest hit.

Stakeholders' perspectives
Bob Breach, Severn Trent Water's head of quality and environment, told the meeting that the water industry welcomed the aims of the Directive. But he criticised the "lack of pace, urgency and leadership from Government" and the "apparent 'defer to the last possible minute' policy".

While heartened by the Environment Agency's latest statistics on river water quality, he thought it inevitable that good ecological status would require further investment in infrastructure from the water industry: "What are customers to make of an almost certain increase in bills that will arise in [2010-2015] as a result of [the Directive]?"

The cost of the Directive to the industry will fall in the PR05 price review in 2009. With average price increases of 30% now being sought by water companies in PR04, Dr Breach questioned whether water customers would have the stomach for more increases to pay for environmental improvements.

Dr Breach said that the industry wants to see the Directive implemented with three key economic tests obeyed - cost effectiveness, proportionality and equitable cost recovery.

The structure of the Directive gives little guarantee of the first two of these. However, much of the industry's enthusiasm for the Directive can be explained by Article 7.

Article 7 requires Member States to identify drinking water sources and ensure that they receive the "necessary protection" to avoid deterioration in quality in order to "reduce the level of purification treatment required".

The industry has long sought an end to the cross subsidy paid by its customers for treatment of water sources polluted by agricultural inputs. Companies will be expecting real progress in reducing pollution by pesticides, nitrates and the phosphate inputs which increase filtration costs by generating excessive algal growth.

Among environmental groups, the Royal Society for the Protection of Birds has been following the Directive's implementation most closely. Ruth Davis of the RSPB maintained that the Environment Agency and Environment Department were predicting an 80-90% failure rate for UK rivers.

However, this was not confirmed by the Agency. Paul Logan maintained that the Agency still had no idea what proportion of waters would meet the requirements, since these are still uncertain.

Ms Davis told ENDS that she expected political pressure to downgrade the Directive's standards to become evident next year: "The regulators are afraid of frightening the horses," she said. "And the horses are frightened. Farmers will regard the setting of high ecological standards as a betrayal of British farming."

The National Farmers Union told a parliamentary inquiry last year that the Directive threatened to impose "very significant costs...that would be unsustainable for most farmers".

The NFU wanted to see the Directive met by "pragmatic improvements along the lines of good agricultural practice, incentive schemes, technology transfer and advice and guidance, if necessary supported by regulation."

It remains to be seen whether the Environment Department and the environment agencies can come up with a package of sufficiently attractive subsidies to bring farmers on board (see pp 12-13347011).

However, without strong measures soon to curb diffuse nutrient inputs, it is unlikely that any substantial improvement in ecological quality of UK waters can be realised before the Directive's 2015 deadline.