Helmut Kroiss, Christoph Lampert, Matthias Zessner

daNUbs-project: Nutrient management in the Danube Basin and its impact on the Black Sea (EVK1-CT-2000-

00051)

NEW CHALLENGES FOR NUTRIENT MANAGEMENT IN THE

DANUBE BASIN

Institute for Water Quality and Waste Management, TU Vienna,AUSTRIA; CO-ORDINATOR

Danube Delta National Institute for Research and Development, Tulcea, ROMANIA

Stichting Waterloopkundig Laboratorium, Delft Hydraulics, Delft, NETHERLANDS

Bureau of Sustainable Agriculture, Hanhofen GERMANY

Institute of Fisheries and Aquaculture - Varna, BULGARIA

Institute for Freshwater Ecology and Inland Fisheries, Berlin, GERMANY

Institute of Hydraulics, Hydrology and Water Resources Management, TU Vienna, AUSTRIA

Institute for Land and Water Management, Petzenkirchen, AUSTRIA

Institute for Marine Research, University Kiel, GERMANY

National Centre for Marine Research, Athens, GREECE

Romanian Marine Research, Constanta, ROMANIA

Institute for Water Pollution Control, Vituki Budapest, HUNGARY

Department of Sanitary and Environmental Engineering, Budapest, HUNGARY

Institute of Public Finance and Infrastructure Policy, TU Vienna, AUSTRIA

Department of Meteorology and Geophysics, University of Sofia, BULGARIA

Institute of Water Problems, Bulgarian Academy of Sciences, Sofia, BULGARIA

Department of Systems Ecology, University of Bucharest, ROMANIA

Partners

map catchment

DANUBE RIVER2.857 km longcatchment: 817.000 km2 Population within: 85 million

BLACK SEATotal catchment: 2.300.000 km2 population within: 190 million surface area of 461.000 km2, average depth 1.240 m.WESTERN BLACK SEAsurface area: 30.000 km2 depth coastline Bulgaria: 70 m, average depth shelf: 140 m

13 Danubian countries (with area >2000 km²)

Danube catchment area

Germany

AustriaHungary

Slovakia

Croatia

Serbia-Montenegro

Romania

Bulgaria

Bosnia-Herce-govina

Czech Republic

Ukraine

Moldova

Slovenia

Aspects of nutrient management

Why are nutrients especially interesting:Nutrients are matter of transboundary transport and

pollutionNutrient discharges affect the marine coastal areas by

eutrophication (even if river quality standards are met)Emissions stem from diffuse and point sourcesStorage capacity of nutrients in the catchment is orders

of magnitude higher than yearly turnover (delays of effects)

Nearly the whole population is contributing (life style)

CONCEPT of the daNUbs project

(i) MONERIS

(ii) DWQM

(iii) DDM

(iv) Shelf Model

(i) nutrient balancesagriculture, nutrition, diffuse

pollution etc.

(ii) transportin rivers

(iii) Effects onBlack Sea

Emissions to surface water

In stream transports, fluxes to Delta

Fluxes to Black Sea

Sources, pathways and stocks in the catchment

Critical nutrient loads

(i) Handbook fornutrient balances

(ii) scenarioevaluation

Processunderstanding

Legend:

Model Strategicplanning

Results

(I.) (II.) (III.)

Solutions for nutrientmanagement

Actual results from Danubs research project

• Danube is the main contributor to eutrophication phenomena in Western Black Sea coastal area.

The situation in WBSC has improved significantly since the late eighties and early nineties. Reduced nutrient inputs led to :

reduced eutrophication (algae production),

Bottom hypoxia has disappeared

regeneration of zoo-benthos and

regeneration of phytoplankton.

• Since 1997 hypoxia has disappeared from the Western Black Sea (RO, BG) except a very short period (1-2 days) in 2003. The situation is close to the sixties now.Hypoxia is clear indicator of eutrophication.

• loads in 1997 (MONERIS): TP 25 kt/a, 400 kt DIN

critical loads??

Saturation of dissolved oxygen near the bottom in September 1996, 1999 and 2003 on the Romanian shelf of the Western Black Sea

from A. Cociasu.

28.6 29.0 29.4 29.8 30.0

43.8

44.0

44.2

44.4

44.6

44.8

45.0

28.6 29.0 29.4 29.8 30.029.8 30.029.8 30.029.8

43.8

44.0

44.2

44.4

44.6

44.8

45.0

28.6 29.0 29.4 29.8 30.028.6 29.0 29.428.6 29.0 29.428.6 29.0 29.4

43.8

44.0

44.2

44.4

44.6

44.8

45.0

43.8

44.0

44.2

44.4

44.6

44.8

45.0

43.8

44.0

44.2

44.4

44.6

44.8

45.0

September 1996 September 2003

Danube

September 1999

Danube Danube

Oxygen saturation at the bottom

Total N- and P-emissions into the Danube river system by pathway

MONERIS Results: Nitrogen loads for river outlets 1998 - 2000

N-retention240 kt/a N

LoadDIN = 390 kt/a NTN = 450 kt/a N

DIN-emissions

}}

MONERIS Results: Phosphorus loads for river outlets 1998 - 2000

P-retention45 kt/a P8.4 kt/a P Iron Gate

P-load22 kt/a P

}}

Decrease since 1990: N: minus, 25%, P minus 50%. P is the limiting nutrient now in the Western Black Sea.

Main reasons for the decrease of nutrient discharges:

• Economic crises Reduced fertilizer applicationReduced fertilizer productionClosure of large animal farms

• Introduction P-free detergents

• P and N removal at treatment plants (A, D,CZ)

• favourable weather conditions (e.g. wind directions)?

Main risks for not reaching good ecological status in respect to WBSC eutrophication:

Development of sewerage (fulfilling EU Urban Waste Water Directive)

Recovery of the economic situation in the Eastern Danubian Countries (EDC) in the future

Actual situation of agriculture is not sustainable from the economic point of view

A “stand-still” scenario can only be related to the nutrient load to the Black Sea but not to the economic development.

Economic development in these countries is desired even it leads to an increase of nutrient emissions e.g. from agriculture in some regions.

Management of nutrient emissions is required even the quality of the Western Black Sea has improved!

connections (% of population)

to sewer systems and ww treatment plants

sewer systems wwtp• Slovak R. 54 51• Slovenia 53 35• Czech R. 75 69• Hungary 61 34• Bulgaria 72 63• Romania 51 30

As compared to:• Germany (Danube Basin) 91 90• Austria 85 84

Impact of the Urban Waste water Directive

about 50% of the population is connected to a sewerage system;

about 20% of the collected waste water is discharged untreated now (40% out of this stem from settlements < 2000 inh.).

85% of the population lives in settlements > 2000 inh. and have to be connected according the Urban Waste Water Directive (UWWD):

UWWD: C-removal is required:

35% N-removal,

0,6 g P/inh.d removal (ca. 30%)

in 2000: 13 200 t P = 0,44 g P/inh.d

laundry detergents: A, D: 0 gP/inh.d

others: 0,08 – 0,74 g P/inh.d

assumption: all countries except A and D use 2 g/in.d in laundry detergents:

+ 37 600 t P = 50 800 t P

= 1,7 g P/inh.d

P-free detergents are an important measure

use of detergents in the DB

Entwicklung der Phosphoremissionen im Donaueinzugsgebiet

0

20

40

60

80

100

120

140

1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 1 2

river

load

s an

d em

issi

ons

[10

00 tP

/a]

diffuse emissionsindustrial and agricultural point sourcesmunicipal point sources

scenarios:1: UWWD without P-removal2: UWWD with P-removal

Danube river load

Development of phosphorus emissions and river loads (Danube discharges to the Black Sea) in the Danube catchment 1955 - 2000 (adopted from Behrendt et al., 2004) and waste water scenarios for future development.

0

20

40

60

80

100

120

140

1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 1 2

river

load

s an

d em

issi

ons

[10

00 tP

/a]

Danube river load

Entwicklung der Phosphoremissionen im Donaueinzugsgebiet

0

20

40

60

80

100

120

140

1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 1 2

diffuse emissionsindustrial and agricultural point sourcesmunicipal point sources

Danube river load

Development of phosphorus emissions and river loads (Danube discharges to the Black Sea) in the Danube catchment 1955 - 2000 (adopted from Behrendt et al., 2004)

Spatial distribution of nitrogen contributing areas; Regional geologic, morphologic and climatic conditions heavily modify N-surpluses

Soluble P reduction from point sources has a fast response in P discharge to the receiving Sea.

Measures for the reduction of diffuse N-emissions have no immediate effects.

The retention in the groundwater (denitrification) heavily modifies the area specific N-surpluses; large areas in “dry” do not contribute to the N-load of the rivers.

Danube Delta and wetlands along the large rivers have only a small relevance for nutrient retention (main flow through main channels)

Summary

The ecological improvement is endangered by the (desired) economic development in the eastern european countries. Increased nitrogen emissions from agriculture in these countries have to be anticipated.

Development of sewerage (fulfilling EU UWWD) has to be strictly bound to adequate waste water treatment with nutrient (N and P) removal otherwise nutrient loads will increase.

A “stand-still” scenario can only be related to the nutrient load to the Black Sea but not to the economic development - nutrient management is crucial

Summary

daNUbs Team

project homepage: http://danubs.tuwien.ac.at/16.12.2004: Conference: “NUTRIENT MANAGEMENT IN THE DANUBE BASIN AND ITS IMPACT ON THE BLACK SEA”Venue: Vienna University of Technology