Aquatic Environment 1999

7. Summary and conclusions

Through the Danish Aquatic Monitoring and Assessment Programme 1998-2003 (NOVA-2003), a comprehensive programme has been implemented for the period 1998-2003 whereby discharges, transport and effects of nutrients, heavy metals and hazardous substances will be monitored in the various parts of the aquatic environment.

Aquatic Environment 1999 is the first report to summarize the results of NOVA-2003. It assesses:

	Discharges of pollutants to the aquatic environment
	The current state of the environment and the overall trends
	The reduction targets and quality objectives set, and the measures implemented to achieve the various targets.

Discharges and inputs of pollutants to the aquatic environment are described in Chapters 3 and 4, with a brief summary being given here in Section 7.1. The current environmental state of the groundwater, watercourses, lakes and Danish marine waters is described in Chapter 5, with a brief summary being given here in Section 7.2.

7.1 Discharges and reduction targets - status and trends

The magnitude of nutrient inputs from most sources depends on the runoff. It is therefore not surprising that the total input of nutrients to the aquatic environment was high in 1998, as this was the second-wettest year since 1874.

Nutrient inputs in 1998

Total nutrient inputs to inland waters in 1998 amounted to approx. 110,000 tonnes nitrogen and approx. 2,100 tonnes phosphorus, cf. Table 7.1. Inputs to Danish marine waters in 1998 amounted to approx. 200,000 tonnes nitrogen and approx. 2,500 tonnes phosphorus, cf. Table 7.2.

	Nitrogen	Phosphorus
Wastewater treatment plants	2,710	274
Separate industrial discharges	66	4
Stormwater outfalls	723	190
Freshwater fish farms	1,241	92
Point sources, total	4,740	560
Agriculture and background1)	102,744	1,366
Sparsely built-up areas	989	226
Diffuse sources etc. total	103,733	1,592
Total	108,473	2,152

1) Atmospheric deposition on open water bodies is included, but comprises only a few tenths of a percent.

	Nitrogen	Phosphorus
Wastewater treatment plants	5,163	600
Separate industrial discharges	1,427	124
Stormwater outfalls	968	252
Fish farming (freshwater and mariculture)	1,508	121
Point sources, total	9,066	1,097
Background1)	12,536	311
Agriculture	135,783	990
Sparsely built-up areas	989	226
Traffic and power	47,025	0
Diffuse sources etc., total	196,333	1,527
Total	205,399	2,624

1) Excluding inputs from adjoining marine waters and biological fixation of atmospheric nitrogen (N₂).

The trend 1989-98

Since 1989, inputs of both nitrogen and especially phosphorus to the aquatic environment have decreased. This trend is attributable to improved treatment of wastewater. In the case of the point sources, the fall seen in the preceding years was superseded by a slight increase in inputs to inland waters in 1998, primarily due to the large amount of precipitation that fell in 1998. The increase is thus not expected to continue under normal climatic conditions.

The relative development in total inputs of nutrients to the aquatic environment relative to the level at the end of the 1980s is illustrated in Figure 7.1.

A

B

Figure 7.1
Relative development in inputs of nitrogen (A) and phosphorus (B) to the aquatic environment (inland and marine waters) from cultivated land, wastewater treatment plants, industry and the atmosphere during the period 1989-98. The 1989 inputs from the atmosphere, wastewater treatment plants and industry have been set to 100. As 1989 was a very dry year, the figures for runoff and inputs from agriculture are instead expressed relative to the average for the period 1981-88.

A tendency towards a slight fall in the diffuse losses of nitrogen to inland waters is apparent. Whether or not this statistically nonsignificant fall is due to reduced inputs from agriculture, sparsely built-up areas or background loss is unclear.

The marked fall in inputs from point sources has not been accompanied by a corresponding fall in inputs from agriculture. Model calculations of the leaching of nitrogen from the root zone indicate a fall of approx. 25% since 1989/90, cf. Section 3.3. This corresponds to a reduction in annual nitrogen leaching from agricultural land of 57,500 tonnes nitrogen per year. This assessment is in good accordance with the assessments made as the foundation for the Action Plan on the Aquatic Environment II, where it was concluded that the regulations implemented up to summer 1998 would reduce nitrogen loading from agriculture by 60,000 tonnes nitrogen per year.

The calculated fall in leaching of nitrogen from fields, however, is not yet reflected in the transport of nitrogen in watercourses and hence in nitrogen input to the marine waters.

In contrast to the calculations, measurements of the atmospheric deposition of nitrogen compounds on the sea reveal a statistically significant fall.

Inputs of hazardous substances

At the present time it is not possible to draw any general conclusions regarding the magnitude and overall trend in inputs of hazardous substances. This is expected to be done in connection with the theme report on hazardous substances planned for publication in 2002.

Agriculture

According to the Action Plan on the Aquatic Environment I, nitrogen losses from agricultural sources should be reduced by a total of 127,000 tonnes N per year from approx. 260,000 tonnes N per year to 130,000 tonnes N per year. The target was divided into 100,000 tonnes N reduction in the nitrogen load from fields and an approx. 27,000 tonnes N reduction in the farmyard load. In addition, farmyard phosphorus load was to be reduced from approx. 4,400 tonnes P per year in 1987 to a level of around 400 tonnes P per year.

Based among other things on NOVA-2003, it can be ascertained that:

	Model calculations of the actual cultivation practice during the period 1990-98 estimate that nitrogen leaching from fields will be reduced by approx. 25% within a period of years.
	The total nitrogen input to agricultural land has decreased 22% since 1985 as a result of improvements in agricultural practice during the monitoring period (1989-98).
	The surplus on the field nitrogen balances for the agricultural monitoring catchments and the country as a whole has decreased by 27-29%, and amounted to approx. 90 kg N per hectare in 1998.
	The phosphorus surplus has decreased correspondingly.
	1998 was the first year in which there was concordance between crop nitrogen requirements (commercially optimal) and the amount of effective nitrogen fertilizer applied (on average) at the national level (cf. Grant et al., 1999). This reflects a positive general trend, although it still encompasses both underfertilization of some fields, e.g. grass, and overfertilization of others.
	The farmyard load has been reduced to a practical minimum corresponding to approx. 5,000 tonnes N and approx. 400 tonnes P per year.

The expected reduction in the groundwater nitrate concentration in the 6 agricultural monitoring catchments as a result of the decreasing nitrogen input to agricultural land is not yet detectable in the upper groundwater. One explanation might be that the groundwater is old and that the nitrate it contains thus derives from the period prior to adoption of the Action Plan on the Aquatic Environment I.

In addition it can be concluded that:

	Overfertilization has been reduced and now takes place on approx. 10% of the land in the 6 agricultural monitoring catchments.
	Approx. 14% of the farms that used livestock manure in 1998 did not comply with the requirements on utilization of the N content of livestock manure.

The nitrogen surplus in the monitoring catchments and the country as a whole entails a considerable potential for leaching. It should be noted that the above-mentioned results are from 1998, which is before the Action Plan on the Aquatic Environment II entered into force. Implementation of the Action Plan on the Aquatic Environment II will further reduce nitrogen inputs. Utilization of the nutrient content of livestock manure is to be further improved and wetlands are to be re-established in order to enhance nitrogen turnover and retention.

The effects of the Action Plan on the Aquatic Environment II are not yet detectable, but the measures will be reflected in measurements and calculations of nitrogen leaching etc. in the coming years. It is expected that full compliance with the regulations already in force and fulfilment of the targets stipulated in the Action Plan on the Aquatic Environment II will enable the goal of a 50% reduction in nitrogen losses to be met. It will take some years past 2003, though, before the full effect of the measures and instruments implemented will be detectable and nitrogen leaching is halved in practice.

The use of commercial and animal fertilizer by the agricultural sector results in an annual phosphorus surplus on the livestock farms because only part of the phosphorus applied is removed in the crops. Thus in 1998, an average of 11 kg phosphorus was applied per hectare and the phosphorus pool in the soil is thus being continually built up. Through the 1990s, the surplus input of phosphorus at field level has been halved. However, it is of vital significance as regards phosphorus loss to the aquatic environment that farmers continue the positive trend and further reduce the amount of phosphorus inputs to the soil. This is rendered difficult by the fact that livestock production is unequally distributed though the country, thus resulting in local and regional phosphorus surpluses. On many livestock holdings, the application of livestock manure alone will result in a phosphorus surplus. In order to reduce the surplus it is important that the livestock manure is distributed optimally and that efforts are continued to reduce the amount of phosphorus in livestock manure through more effective feeding practices.

The loss of phosphorus from cultivated land is of great significance for the environmental state of the lakes and coastal waters in particular. It is therefore necessary to further improve agricultural practice so as to ensure that the amount of phosphorus applied corresponds to the needs of the crop. This will enhance the possibilities for attaining the environmental quality objectives in many Danish lakes and certain coastal waters.

Municipal wastewater treatment plants

According to the 1987 Action Plan on the Aquatic Environment, nitrogen discharges from municipal wastewater treatment plants were to be reduced from a level of 18,000 tonnes N per year to 6,600 tonnes N per year. Phosphorus discharges were to be reduced from 4,470 tonnes P per year to 1,220 tonnes P per year.

The Action Plan on the Aquatic Environment's reduction targets for discharges from municipal wastewater treatment plants were attained in 1996 for both nitrogen and phosphorus. Monitoring of discharges from treatment plants shows that:

	5,166 tonnes N, 601 tonnes P and 3,525 tonnes organic matter (BOD5) were discharged in 1998.
	Discharges of nitrogen, phosphorus and organic matter have been reduced by 74%, 90% and 94%, respectively, relative to discharge levels at the time the Action Plan on the Aquatic Environment was adopted. The reduction targets for nitrogen and phosphorus were 60% and 72%, respectively.
	The measured concentrations of heavy metals in the effluent from 4 wastewater treatment plants where measurements were made in 1998 were generally lower than the quality criteria for the recipient waters and hence were not critical relative to the criteria.

Industrial discharges

When the Action Plan on the Aquatic Environment was adopted in 1987 it was decided that separate industrial discharges were to be reduced by 3,000 tonnes N and 1,050 tonnes P, cf. Table 6.1. Nitrogen was to be reduced from 5,000 tonnes N per year to 2,000 tonnes N per year while phosphorus was to be reduced from approx. 1,250 tonne P per year to approx. 200 tonnes P per year.

From the monitoring results it is apparent that the reduction targets stipulated in the Action Plan on the Aquatic Environment for separate industrial discharges have been met. Thus:

	separate industrial discharges in 1998 amounted to 1,248 tonnes nitrogen, 124 tonnes phosphorus and 10,700 tonnes organic matter (BOD5), and
	discharges of nitrogen and phosphorus have been reduced by 71% and 90%, respectively, since adoption of the Action Plan on the Aquatic Environment, as compared with the reduction targets of 60% and 82%, respectively.

The discharge figures for hazardous substances are based on company in-house control data and county supervision data. The relevant information is lacking for 4 of the 14 Danish counties. There is therefore some uncertainty as to the actual amounts of hazardous substances discharged via separate industrial discharges, both as regards individual outfalls and on a national level. The monitoring work under NOVA-2003 planned for the next few years is intended to determine the magnitude of the problem. Thus from the year 2000, in-house control and county supervision will be supplemented with measurements at 17 selected companies with separate industrial discharges.

Reduction target status

With regard to the sector-specific reduction targets stipulated in the Action Plan on the Aquatic Environment I it can be concluded that:

	discharges of both nitrogen and phosphorus from wastewater treatment plants and industry have been reduced by more than stipulated in the Action Plan on the Aquatic Environment I,
	agriculture has attained the reduction target for the farmyard phosphorus load,
	agriculture has reduced the farmyard load for nitrogen by approx. 20-30,000 tonnes N per year to a practical minimum of approx. 5,000 tonnes N per year, and
	model calculations of actual cultivation practices during the period 1990-98 show that nitrogen leaching as a whole is expected to decrease by 25% over a period of years, corresponding to a potential reduction in the nitrogen load from fields of approx. 57,500 tonnes N per year (260,000 - 30,000) x 25%).

The present situation is thus that the targets stipulated in the Action Plans on the Aquatic Environment have not yet been fully attained, among other reasons because the Action Plan on the Aquatic Environment II will not have been fully implemented until 2003.

Nitrogen

Phosphorus

Figure 7.2
Reductions attained as per 1998 relative to the reduction targets stipulated in the action Plan on the Aquatic Environment I. If the status column is higher than the target column, the discharge has been reduced more than expected. Wastewater treatment plants and industry are assessed on the basis of the actual discharges in 1998. The estimated reduction in agricultural discharges of nitrogen is 57,500 + 25,000 = 82,500 tonnes per year.

Other sources of pollution of the aquatic environment

The Action Plan on the Aquatic Environment I did not stipulate specific reduction targets for sources such as freshwater fish farms, mariculture, stormwater outfalls and sparsely built-up areas.

Freshwater fish farms

The total discharge of nutrients from freshwater fish farms in 1998 was roughly the same as in the preceding four years - 1,250 tonnes N per year and 100 tonnes P per year. Since 1989, when the statutory order governing the organization and operation of freshwater fish farms entered into force, discharges have fallen considerably. The requirements of the statutory order that discharges be reduced seem to have had the desired effect. Further significant reductions in discharges as a result of the statutory order cannot be expected.

Consumption by fish farms of certain auxiliary substances seems to have increased relative to earlier years. Future attention will be focused on their consumption of medicines and auxiliary substances, in particular the magnitude of discharges and possible effects on the aquatic environment. In addition, consumption of these substances needs to be more closely coupled to the actual need for them.

Mariculture

Total discharges of nutrients from mariculture - both sea-based and land-based seawater fish farms - in 1998 were largely the same as in earlier years, i.e. approx. 300 tonnes N per year and just under 35 tonnes P per year. Even though discharges from mariculture are small relatively speaking, they can have significant effects locally.

Stormwater outfalls

Stormwater overflows are currently one of the reasons why many watercourses and lakes do not meet their quality objectives. In step with the reduction in discharges to inland waters from wastewater treatment plants and industry over the past 10 years, the impact of stormwater overflows on watercourses and lakes has become more apparent.

In 1998, discharges from stormwater outfalls amounted to approx. 968 tonnes nitrogen and 253 tonnes phosphorus. No general trend can be detected in discharges from stormwater outfalls.

Very little is known regarding how best to regulate stormwater outfalls. The Danish EPA is therefore participating in work that will result in proposals for guidelines that can be incorporated in official Danish EPA Guidelines. The work is expected to be completed in 2001.

Sparsely built-up areas

As with stormwater outfalls, the relative significance of discharges from sparsely built-up areas has increased in step with the reduction in discharges from wastewater treatment plants. The discharges from sparsely built-up areas - especially of organic matter and phosphorus - are responsible for many watercourses and lakes failing to meet their quality objectives.

Discharges from sparsely built-up areas in 1998 amounted to approx. 998 tonnes nitrogen and 228 tonnes phosphorus with the tendency being towards a decrease.

In the country as a whole, there are presently approx. 67,000 properties in rural areas that have individual discharges. As a result of a 1997 amendment of the Environmental Protection Act concerning wastewater treatment in rural areas these properties will have to improve sewerage and discharge conditions within the coming years. This will help improve the environmental state of inland waters, especially that of the small watercourses.

Hazardous substances

It can also be concluded that implementation of the Esbjerg Declaration's goal that the levels of hazardous substances etc. in the aquatic environment should be reduced to background levels in the case of naturally occurring substances and close to zero for true hazardous substances is still in its initial phase. The current status is that:

	the Pesticide Action Plan goal of halving consumption of pesticide active substance has for all intents and purposes been attained since sales of active substance have been reduced by 48%,
	the Pesticide Action Plan's goal of reducing pesticide treatment frequency has not been attained, and
	national strategies etc. for reducing pollution of the aquatic environment with hazardous substances etc. have already been adopted or are in the process of being adopted.

Future endeavours for a cleaner aquatic environment

In connection with the political agreement behind the Action Plan on the Aquatic Environment II it was agreed that a status report on the plan should be prepared at the end of the year 2000. This status report will focus on:

	an overall assessment of nitrogen balances, losses and the uncertainty associated with them,
	an assessment of the effects of the measures adopted, and
	means to reduce ammonia volatilization from agriculture.

As far as concerns further reductions in discharges from point sources, special emphasis will be placed on ensuring that:

	discharges of hazardous substances are limited through revision of discharge permits issued to wastewater treatment plants and industrial companies and permits for the connection of industrial discharges to municipal wastewater treatment plants,
	county and municipal authorities actually enforce the discharge permits issued in practice,
	in connection with their wastewater treatment plans, the Municipalities draw up targets and prioritized plans for renovating the municipal sewers in accordance with the Government's 1994 agreement with the National Association of Local Authorities in Denmark on renovation of the sewer network,
	all Counties submit information on discharges of hazardous substances from industrial enterprises etc., in the year 2000, and
	discharges of nutrients, auxiliary substances and medicines from freshwater fish farms and mariculture are reduced.

7.2 State of the aquatic environment - status and trend

The general state of the aquatic environment in Denmark has not changed significantly relative to previous years (1989-97).

Groundwater

After a couple of dry years, when the groundwater table was unusually low, it returned to a more normal level during the course of 1998, when the autumn in particular was very wet. Water abstraction in 1998 was extremely low: 741 million m³. The total abstraction has fallen by approx. 30% from 1989 to 1998, among other reasons because of water taxes and water-saving measures.

The groundwater monitoring shows that:

	nitrate continues to comprise a problem - especially in sandy-soil areas of Jutland. No clear trend can be detected during the monitoring period (1990-1998),
	in several localities, heavy metals and inorganic trace elements such as barium, aluminium, nickel and zinc are present in the groundwater in concentrations exceeding the limit value for drinking water. Several of the substances are naturally occurring in the groundwater and are to a large extent removed by ordinary water treatment at the waterworks. No clear trend is apparent in the occurrence of the substances during the monitoring period (1990-1998),
	organic micropollutants have been detected in nearly all abstraction wells at one time or another. The organic micropollutants comprise a large group of substances that can derive both from industry (e.g. chlorinated hydrocarbons) and from households (e.g. detergents), and which can also be formed naturally (e.g. chloroform). The majority occur in the groundwater in concentrations well under the limit values for drinking water. No clear trend is apparent during the monitoring period (1990-98),
	pesticides and pesticide residues are found in the upper groundwater in 40% of the abstraction filters investigated. In the deeper groundwater, pesticides are found in approx. 29% of the wells, with the pesticide content exceeding the limit value for drinking water in approx. 8%. The trend over the period 1994-98 is towards increasing detection of pesticides and pesticide residues - also at levels exceeding the limit value for drinking water. This is considered to be largely attributable to the fact that more substances are measured now than previously, and
	a decrease in the concentration of atrazine has been detected in the upper groundwater in the agricultural monitoring catchments.

It should be noted that all the pesticides or pesticide residues detected most frequently and in the highest concentrations are currently either prohibited or strictly regulated.

A general finding with regard to the groundwater monitoring is that with few exceptions, no clear trends are detectable for the substances analysed during the monitoring period (1990-98). Among other reasons this is attributable to the fact that the majority of the groundwater analysed was formed prior to adoption of the Action Plan on the Aquatic Environment.

The further work on ensuring clean groundwater will be based on the Government's 1994 10-point Programme for protection of the groundwater and drinking water and the Drinking Water Committee's 1997 report. Emphasis will be placed on:

	preserving the Danish water supply structure, which is based on decentralized abstraction of pure groundwater, and
	ensuring that curtailment of nutrient discharges to the groundwater takes place through promotion of organic farming, protection of particularly vulnerable groundwater abstraction areas, enhanced afforestation, and nature restoration, cf. the Government's 10-point Programme.

The recommendations of the Drinking Water Committee have been implemented in legislation in connection with the Action Plan on the Aquatic Environment II, which introduces the possibility to protect vulnerable areas through agreements with the agricultural sector, etc. With respect to pesticides, though, this necessitates building up the scientific foundation for identification of areas that are particularly vulnerable to pesticide leaching. A new measure is the power to impose restrictions on land use in return for full compensation. Regulations governing cooperation between county and municipal authorities and the waterworks have also been established and the possibility has been introduced to finance groundwater protection through water charges.

The recommendations of the Drinking Water Committee concerning safeguarding the groundwater resource against pollution by hazardous substances has, as with nutrients, led to the implementation of new measures. The county authorities identify sensitive agricultural areas where there is a need for special efforts to safeguard drinking water interests.

The overall framework for implementing goal-oriented, prioritized protection of the groundwater has now been established. However, considerable work remains on preparing official guidelines, statutory orders, etc. stipulating in detail the technical and administrative requirements pertaining to protection of the groundwater. It will therefore be several years before the work on drawing up official guidelines and statutory orders etc. is completed.

Watercourses and springbrooks

The watercourse monitoring shows that:

	the concentration of nitrogen in watercourses in cultivated catchments has fallen approx. 5% since 1989 when corrected for inter-annual variation in runoff. The fall is not statistically significant, however,
	there has been a corresponding marked fall in the concentration of total-P in the watercourses that were previously highly affected by wastewater from freshwater fish farms and treatment plants when corrected for the variation in runoff,
	discharges of phosphorus from sparsely built-up areas still comprise a major part of the total-P input to watercourses, and
	the concentrations of phosphorus in watercourses in cultivated catchments are still 3-fold greater than in watercourses in uncultivated catchments.

In addition, it can be concluded that the nitrate concentration of springs in cultivated areas is increasing, but that the increase does not correlate with the tendency towards a falling nitrogen concentration in many watercourses. One explanation could be that the groundwater in the springs is relatively old and hence might reflect agricultural practice in the years prior to adoption of the Action Plan on the Aquatic Environment.

NOVA-2003 and county watercourse supervision show that environmental quality is only acceptable in approx. 40% of watercourse reaches. The unacceptable state of the remaining 60% of watercourse reaches is often due to poor physical variation, for example as a result of channelization and hard-handed maintenance practices. Nevertheless, there are still some watercourses where the unacceptable environmental state is attributable to pollution from point sources and sparsely built-up areas.

Assessment of the environmental state of watercourses is not undertaken in the same manner in NOVA-2003 and the county watercourse supervision. This gives an inhomogeneous basis for a nationwide assessment of the current state and overall trend in watercourse quality. The recommended method - the Danish Stream Fauna Index - therefore needs to be used more widely as the assessment method.

The future endeavours to improve the environmental state of Danish watercourses will focus on ensuring that:

	efforts to create better physical conditions in the watercourses are enhanced and that restoration work is continued,
	watercourse authorities enforce the provisions of the Watercourse Act stipulating a 2-m wide cultivation-free border zone alongside all natural watercourses or watercourses with a high quality objective,
	the Counties in future employ the Danish Stream Fauna Index to such an extent and manner as to enable the county watercourse supervision data and NOVA-2003 to together provide a nationwide assessment of the environmental state of Danish watercourses, and
	measures are taken to re-establish good natural and environmental quality in watercourses where obstructions have a major negative impact on watercourse quality and hinder fulfilment of the quality objective.

Lakes

As a result of eutrophication, many Danish lakes have become so nutrient-rich that they have switched from a clearwater to a turbid state. Eutrophication has a number of negative effects on lake environmental quality. As a general rule, increasing eutrophication leads to impoverishment in the direction of fewer plant and animal species. Two important examples are the submerged macrophytes, which often disappear or markedly regress in the turbid water, and the fish stock, which becomes dominated by large populations of just a few species. In order to rectify these undesirable conditions, efforts have been going on for many years to reduce nutrient inputs to the lakes.

The lake monitoring results reveal that the majority of the investigated lakes are improving as a result of the reduction in nutrient inputs. Among other things this is reflected in:

	an increase in the water's Secchi depth,
	a decrease in planktonic algal biomass, and
	a tendency towards a greater depth distribution of submerged macrophytes.

It can also be ascertained, however, that:

	on the national scale, only 32% of lakes investigated fulfil their quality objectives, and
	there has not been any detectable improvement in compliance with quality objectives during the monitoring period (1989-1998).

The failure of Danish lakes to meet their quality objectives is largely attributable to the fact that nutrient discharges have not yet been reduced sufficiently. The main sources of this loading are probably diffuse inputs from cultivated land, point sources and sparsely built-up areas.

A basic premise for being able to improve water quality is that external nutrient inputs have to be reduced sufficiently. This means that the lake water concentration has to be reduced below an equilibrium concentration of 0.05-0.10 mg phosphorus per litre in shallow lakes and 0.02-0.05 mg phosphorus per litre in deep lakes. This can only be achieved by reducing nutrient inputs, especially phosphorus inputs, from cultivated land and sparsely built-up areas. Due to the resilience of lake ecosystems, the reduction in nutrient loading will not always lead to an immediate improvement. In the lakes where external nutrient loading has been reduced sufficiently, an improvement in environmental state can sometimes be promoted through lake restoration methods.

Marine waters

Monitoring of the marine waters shows that:

	the concentrations of phosphorus in the sea are still falling.
	there is a weak tendency towards a fall in the concentration of nitrogen.
	the incidents of oxygen deficiency in 1998 were limited in extent in the shallow estuarine fjords and coastal waters. In the deep marine waters with a stratified water column, it was mainly the areas that naturally suffer from oxygen deficiency that were affected.
	the concentrations of PAHs and heavy metals (with the exception of organotin compounds) in fish and mussels are less than the concentrations considered critical in an international context, and
	the concentrations of hazardous substances in fish and mussels are generally at a level considered to be of no significance.

The monitoring results also show that:

	the environmental state is very rarely satisfactory, largely due to high nutrient concentrations in the water, restricted distribution of perennial submerged macrophytes, oxygen deficiency, or the occurrence of undesirable, pollution-dependent plant growths,
	extremely high concentrations of hazardous substances can occur locally,
	the TBT concentration in fish and mussels is between 2- and 100-fold greater than the recommended international assessment criteria,
	TBT-induced hormonal disturbances have been detected in the majority of snails in the inner Danish marine waters, and
	the PCB concentration in fish and mussels is at a level where the occurrence of ecological effects cannot be excluded.

The progress so far made in reducing nutrient inputs to the sea have been insufficient to lead to a general improvement in environmental state. In the two dry years 1996 and 1997, inputs of nutrients to the sea were so low as to correspond to the expected effect of the Action Plans on the Aquatic Environment. The environmental state of the marine waters improved considerably during these two years. Among other things this was reflected in enhanced Secchi depth, enhanced depth distribution of eelgrass, less filamentous brown algae and sea lettuce, as well as less frequent and less severe oxygen deficiency.

The clear effects of tributyl tin presently detected in sea snails will presumably decrease considerably in step with implementation of the newly adopted international ban on its application (2003) and use (2008).

Pollution of the sea is a transboundary problem. It is therefore important that the reduction targets are achieved both nationally and by our neighbouring countries.

7.3 Overall conclusion

Progress towards improving the Danish aquatic environment is being made on many fronts. Discharges etc. of pollutants are decreasing as expected. It can thus be ascertained that:

	wastewater treatment plants and industry have reduced discharges of nitrogen and phosphorus by more than stipulated in the Action Plan on the Aquatic Environment I,
	the farmyard load has been reduced to a practical minimum corresponding to approx. 5,000 tonnes N per year and approx. 400 tonnes P per year,
	the nitrogen load from fields could be reduced by 25% within the space of some years, corresponding to 57.500 tonnes N per year,
	measured atmospheric deposition of nitrogen on marine waters is decreasing slightly, and
	pesticide sales to agriculture (measured in tonnes active substance) have been reduced by 48% and than the use of a number of pesticides, including those that most threaten the groundwater, has been prohibited or strictly regulated.

The general state of the aquatic environment in Denmark has not changed significantly relative to previous years, however. The nitrogen surplus still comprises a major problem, among other things in the form of nitrate contamination of the groundwater and springs. In the sea, it results in enhanced plant growth and unnaturally expansive and severe incidents of oxygen deficiency. The phosphorus surplus is also a considerable problem, especially in the lakes and certain coastal waters. The detection of hazardous substances in abstraction wells and in many watercourses and lakes and the sea is worrying.

There is no doubt, though, that with the existing action plans, strategies and international agreements Denmark is on the right track, and that once they have had time to take effect, improvement in the state of the aquatic environment will follow.