Nutrient reduction strategies in Denmark
The primary means of achieving the quality objectives for surface waters
is a reduction in nutrient discharges and emissions.
In the January 1987 Action Plan on the Aquatic Environment and the April
1987 Report on the Action Plan on the Aquatic Environment the goal of
reducing nitrogen and phosphorus loads to the aquatic environment was
set to 50% and 80%, respectively. This corresponds to a reduction in annual
discharges and losses from a level of around 283,000 tonnes N and 9,120
tonnes P at the time the plan was adopted to a level of ca. 141,600 tonnes
N and ca. 1,820 tonnes P (see Table 3.1 for details).
The Action Plan covers the 3 major sources: agriculture, municipal wastewater
treatment plants and separate industrial discharges.
It should also be noted that losses of phosphorus from cultivated land
are not included, because of the uncertainties that are related to these
Since the mid 1980s, a number of action plans and strategies have been
adopted by the Danish Parliament to regulate development of the agricultural
sector, one of the main sources of nutrients to the aquatic environment,
and its impact on the aquatic environment. The action plans include:
- The 1985 NPo (Nitrogen, phosphorus and organic matter) Action Plan.
- The 1987 Action Plan against Pollution of the Danish Aquatic Environment
with Nutrients (Action Plan on the Aquatic Environment).
- The 1991 Action Plan for Sustainable Agriculture.
- Parts of the Governments 10-Point Programme for Protection of the
Groundwater and Drinking Water from 1994.
- The 1996 Follow-up on the Action Plan for Sustainable Agriculture.
- The 1998 Action Plan on the Aquatic Environment II.
Reduction targets for nitrogen and phosphorus stipulated in the Action
Plan on the Aquatic Environment I are an approximate 50% reduction of
nitrogen loads and the elimination of the phosphorus farmyard load to
avoid unintended eutrophication of the aquatic environment. The reduction
targets were to be attained by 1993 through the following measures carried
out by the agricultural sector:
- Establishment of sufficient capacity to store 9 months of manure production
so that manure can be stored until crop growth season begins.
- Establishment of crop rotation and fertilisation plans to ensure that
nitrogen content of fertiliser is optimally exploited.
- Fields must have green cover during winter period.
- Manure has to be ploughed in or in some other way deployed into the
soil within 12 hours of application.
- Limits on the amount of livestock manure applied to fields.
It soon became clear that it would not be possible to attain the reduction
targets by 1993. The measures stipulated in the Action Plan on the Aquatic
Environment I were therefore tightened in 1991 in the Action Plan for
Sustainable Agriculture. The reduction target was maintained but the time
frame was extended to the year 2000. The measures were:
- Fertilisation accounts so that fertiliser application can be documented.
- More stringent and fixed requirements on utilisation of the nitrogen
content of livestock manure.
- All farms must establish sufficient capacity to store 9 months of
A ban on the application of liquid manure between harvest time and February
except on fields cultivated with winter rape or grass. After the Action
Plan for Sustainable Agriculture, there have been a number of follow-up
plans for reducing the impact of the agricultural sector on the aquatic
environment, including the Government’s 1994 10-Point Programme
for Protection of the Groundwater and Drinking Water in Denmark.
The need to further tighten the regulation of agricultural loads
of nitrogen has become even more necessary because Denmark must comply
with the EU Nitrates Directive by the year 2003. The directive restricts
application of livestock manure to 170 kg N hectare-1 yr-1.
In the case of some types of farms this is less than levels currently
permitted. Denmark has sought permission to derogate from the 170 kg N
hectare-1 rule on cattle holdings so as to enable application
of up to 230 kg N hectare-1 yr-1 on a small number of these
In February 1998, the Danish Parliament adopted several new instruments
aimed at achieving the reduction targets stipulated in the Action Plan
on the Aquatic Environment I. As a supplement to the Action Plan on the
Aquatic Environment I, the Action Plan on the Aquatic Environment II will
reduce nitrogen leaching by a further 37,000 tonnes N yr-1 so as to enable
the reduction target of 100,000 tonnes N yr-1 to be achieved
no later than the end of the year 2003 (table 3.2).
The following measures have been implemented under the Action Plan on
the Aquatic Environment II:
- Re-establishment of 16,000 hectares of wet meadow to help reduce
nitrogen leaching to the aquatic environment due to their ability to
convert nitrate to N2.
- Afforestation in Denmark and planting 20,000 hectares forest before
the year 2002.
- Agri-environmental measures including financial support to farmers
willing to utilise sensitive agricultural areas in a more environmentally
sound manner by using less fertiliser or by completely refraining from
cultivating the land. There has hitherto been very little interest in
- Improved fodder utilisation and changes in feeding practice.
- Implementation of stricter harmony criteria governing livestock density.
- Stricter requirements on utilisation of the N content of livestock
- Converting 170,000 hectares to organic farming; catch crops on a further
6% of a farmers land.
- Reducing the nitrogen norm by 10%, e.g. farmers may now only apply nitrogen
in amounts corresponding to 90% of the economically optimal level.
If the measures in the Action Plan on the Aquatic Environment II are
implemented as changes in agricultural practice, 20 years of nitrate policy
(1985-2003) is likely to result in a 100,000 tonnes N yr-1
reduction in leaching from agricultural land. Moreover, consumption of
nitrogen in the form of commercial fertiliser will decrease from approximately
400,000 tonnes N yr-1 in 1985 to approximately 200,000 tonnes
N yr-1 in 2003 (Iversen et al. 1998).
In connection with the Action Plan on the Aquatic Environment I it was
estimated that nitrogen loads could be reduced by a total of 127,000 tonnes
N yr-1 by 1993. The reduction targets were 100,000 tonnes N
yr-1 for the nitrogen load from fields and 27,000 tonnes N
yr-1 for the farmyard load. In the Action Plan for Sustainable Agriculture
it was estimated that by the year 2000, the measures stipulated in the
Action Plan on the Aquatic Environment I would only have reduced nitrogen
loads by 50,000 tonnes N yr-1 and that further measures were
therefore needed to achieve the total reduction of 127,000 tonnes N yr-1.
The existing measures and targets under the Action Plan on the Aquatic
Environment I and the Action Plan for Sustainable Agriculture were reevaluated
in 1998 in connection with the preparation of the Action Plan on the Aquatic
Environment II. It was concluded that by the year 2003, the existing measures
would reduce nitrogen loads by 89,900 tonnes N yr-1. Together
with the expected reduction under the Action Plan on the Aquatic Environment
II, it was concluded that nitrogen loads would be reduced by 127,000 tonnes
N yr-1 by 2003.
Not all measures in the Action Plan on the Aquatic Environment II will
have taken full effect by 2003. The Action Plan on the Aquatic Environment
II also encompasses so-called regional measures. These represent implementation
of recommendations of the Drinking Water Committee concerning the protection
of groundwater resources considered particularly vulnerable to nitrate
Discharges from municipal wastewater treatment plants are regulated by
the Environmental Protection Act, the Urban Wastewater Directive and derivative
statutory orders and official guidelines.
The EU Council Directive 91/271/EEC of 21 May 1991 concerning Urban Wastewater
Treatment as amended by Commission Directive 98/15/EU of 27 February 1998
- commonly referred to as the Urban Wastewater Directive – is one
of the most important legal documents in the EU legislation on the aquatic
environment. The purpose of the directive is to protect the environment
against negative effects associated with discharge of inadequately treated
urban wastewater and biologically degradable industrial wastewater from
enterprises within the food processing industry. According to the directive,
wastewater discharges have to be subjected to a level of treatment appropriate
to the environment at the place in question and the use to which the recipient
water bodies in question are put. Denmark implemented the provisions of
the directive in Danish legislation in 1994.
The Action Plan on the Aquatic Environment’s reduction targets
for municipal wastewater treatment plants were adjusted in 1990 on the
basis of the results of the Nation-wide Monitoring Programme (Danish
EPA, 1991). In the case of nitrogen, annual discharges in treated
wastewater are to be reduced from ca. 18,000 tonnes N to ca. 6,600 tonnes
N. Phosphorus discharges are to be reduced from ca. 4,470 tonnes P to
ca. 1,220 tonnes P. The reduction in nitrogen discharges from municipal
wastewater treatment plants corresponds to all new or upgraded plants
exceeding 5,000 PE and all existing plants exceeding 1,000 PE having to
implement biological treatment with nitrogen removal down to an annual
average of 8 mg N l-1. In 1987 this was considered as low as
it is practically possible to reach with biological nitrogen removal.
As regards to phosphorus, municipal wastewater treatment plants exceeding
5,000 PE have to remove phosphorus down to an annual average of 1.5 mg
The reduction target for nitrogen of 6,600 tonnes N yr-1 was
achieved in 1996, as was the reduction target for phosphorus of 1,200
tonnes P yr-1.
The Environmental Protection Act, the EU Directive on Pollution Prevention
and Control (IPPC Directive) and derivative statutory orders and official
guidelines regulate separate industrial discharges.
The IPPC Directive aims at integrated prevention and control of pollution
by major industries. The directive specifically regulates the energy industry
(power stations and refineries, etc.), production and processing of metals,
the mineral industry, the chemical industry, waste management plus a number
of other activities such as paper manufacturers, textiles pre-treatment
and dyeing, slaughterhouses and dairies, as well as installations for
intensive rearing of poultry and pigs exceeding a certain capacity. The
IPPC Directive contains measures designed to prevent or, where that is
not practicable, to reduce emissions to the atmosphere, water and land
from the above mentioned activities.
Because of large differences between individual enterprises and their
discharges of wastewater, the Action Plan on the Aquatic Environment I
did not stipulate general discharge requirements for industry as for wastewater
treatment plants. Industry was to reduce its discharges through application
understood as the level of treatment that is technically attainable and
economically viable for the industry in question.
A number of other sectors and types of sources also contribute to nutrient
loading to the aquatic environment. These include freshwater fish farms,
mariculture, transport, combustion plants (heat and power production),
sparsely built-up areas and stormwater outfalls. The Action Plans on the
Aquatic Environment did not specify specific reduction targets for these
sectors and types of source but instead describes a number of other measures.
The Ministry of Environment issued the Statutory Order on Freshwater Fish
Farms on 5 April 1989 to reduce nutrient loading. It gives guidelines
for the County authorities to stipulate the maximal permitted feed consumption
at fish farms, minimum requirements as to treatment measures as well as
minimum requirements as to utilisation and quality of feed.
In 1987 a moratorium was placed on establishment of new farms and expansion
of existing farms until 1990 when Statutory Order No. 640 on mariculture
was issued. This stipulated general regulations on feed quality and consumption
as well as consumption of feed relative to production. In addition, upper
limits were placed on nutrient discharges to the surrounding aquatic environment
from each individual farm. In 1996 the Danish EPA requested the Counties
not to issue any permits for new sea-based or land-based mariculture farms
or for extensions of existing farms and were urged to assess whether environmental
or operational benefits could be obtained by moving or merging existing
farms. In June 2001 the 1996 request was lifted and the Danish EPA published
a new strategy to reduce loads of nutrients and organic matter from mariculture.
A revision of the existing Statutory Order is being negotiated and is
expected to be implemented in 2003.
When the Action Plan on the Aquatic Environment was adopted in 1987, the
Danish EPA was instructed to prepare a report containing a specific reduction
programme for power station NOx emissions. Regulation
of NOx emissions in Denmark has concentrated on
improved combustion technology and flue gas abatement at power stations
(e.g. Statutory Order No. 885 of 18 December 1991 on Limitation of Emissions
of Sulphur Dioxide and Nitrogen Oxides from Power Stations), enhanced
use of natural gas and renewable energy (e.g. the Government’s 1990
Energy Action Plan) as well as implementation of the requirement for catalytic
converters on cars (e.g. Ministry of Justice Statutory Order on Detailed
Regulations for the Motor Vehicle Design and Equipment from 1990). Under
the EEC Convention on Transboundary Air Pollution, Denmark has entered
into an international agreement to reduce emissions of NOx
by 30% over the period 1986-98. However, the measures needed to meet this
goal are inadequate in Europe as regards acidification and eutrophication.
In June 1999, the EU Commission, therefore, issued proposals for two directives
on acidification and ozone formation at ground level (Proposal for a Directive
on National Emission Limits for Certain Polluting Substances and Proposal
for a Directive on the Ozone Content of the Air). These two directives
stipulate national limits for emissions of NH3 and NOx.
In the case of Denmark, the proposed directives will limit ammonia (NH3)
emissions to 71,000 tonnes per year and nitrogen oxide (NOx)
emissions to 127,000 tonnes per year from 2010.
The relative contribution of nutrients from sparsely built up areas has
in-creased over the past 10 years because of point source reductions from
wastewater treatment plants and industry. It is expected that future improvements
in treatment of wastewater from sparsely built-up areas will occur resulting
from initiatives in connection with the 1997 amendment of the Environmental
Protection Act concerning wastewater treatment in rural areas. According
to state instructions to the Counties concerning revision of the Regional
Plans in 2001, the Countries have specified areas in which the treatment
of wastewater from properties in rural areas is to be improved, they must
stipulate quality objectives for individual recipient waters in its Regional
Plan, identify watercourses and lakes that are vulnerable to pollution,
and based on its knowledge of the environmental state and pollution load
on the individual recipient waters, has to assign each individual recipient
a maximal environmentally permissible level of pollution.
Rainwater outfalls are one of the reasons that many watercourses and urban
lakes as well as some coastal marine waters fail to meet the agreed quality
objectives. Despite the increasing importance, there is a lack of knowedge
of how to manage rainwater outflows. Ongoing work by the Wastewater Committee
under the Danish Engineering Association and the Danish EPA is intended
to result in proposals for guidelines that can be incorporated in official
The effects for a number of measures in Action Plan II from 1998 are based
on an assumed development in agricultural practises. Therefore, the plan
was subject to a mid-term evaluation in 2000/2001. This evaluation concluded
that the realised changes in agricultural practices could not match the
expected changes. The losses of nitrogen from field were estimated to
be 93,000 tonnes of N, indicating an annual under-fulfilment of 7,000
tonnes of N. The results of the political mid-term evaluation were presented
in May 2001. The conclusions included:
- Changed rules for funding of reestablishment of wetland, in order
to make this more attractive.
- Reduction of bread wheat subsidies in order to ensure that the area
receiving subsidies matches the needs for bread wheat.
- Revision of nitrogen standards.
The amendments to Action Plan II include an over-fulfilment by 175 tonnes
N yr-1 compared to the measures agreed in 1997.
An Action Plan III on the Aquatic Environment is on the programme of the
Danish Government and is planned to be negotiated in 2003. The parties
behind Action Plan I and II have agreed that Action Plan III shall focus
- The nitrogen balance of the Danish agricultural sector, in particular
on the magnitude of losses from Danish agriculture in the mid 1980s.
- General measures to reduce discharges and losses from the agricultural
- Losses of phosphorus from fields, which so far have been excluded
from action plans.
- Possibilities to implement regional measures in order to protect specific
Sector specific reduction targets for annual discharges
and losses of nitrogen (tot-N) and phosphorous (tot-P) in tonnes to the
aquatic environment in Denmark (Danish EPA, 2000).
|Seperate industrial discharges
|Seperate industrial discharges
Summary of measures and estimated reductions (in
tonnes N per year) in nitrogen discharges and losses from agriculture,
cf. Action Plan on the Aquatic Environment I, Action Plan for Sustainable
Agricultural Development, follow-ups hereto, and Action Plan on the Aquatic
||Action Plan on the Aquatic Environment I
||Optimal utilisation of livestock manure
• NPo Action Plan
• NPo Subsidy Act
• Further initiatives
Programme for improved utilisation
• Systematic fertilisation plans
Improved application methods
• Winter green fields –
catch crops and
ploughing down of straw
• Winter green fields – further
||Action Plan for Sustainable Agricultural
|| • Improved utilisation of livestock manure
in commercial fertiliser
• Protection of groundwater in particularly
• Reduction in agricultural acreage
• Structural development, other measures
||Action Plan on the Aquatic Environment II
|| • Wetlands
• Sensitive agricultural areas
• Improved fodder utilisation
• Stricter livestock density requirements
requirements on utilisation
of N content of manure
• Organic farming
crops on a further 6% of the fields
• 10 % reduction in