EWA Brussels Conference 2013 «Water – Investing Today for the Future
The Oslo Fjord – a blue jewel – how to preserve it in a future mega-Oslo with Climate change ?
Haakon Thaulow NIVA Norwegian Institute for Water Research
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Outline - • The Inner Oslofjord – a blue jewel • Water pollution abatement - a sucess story • Challenges – urban growth and climate change • Goals – the role of the Water Framework Directive • New measures needed ! • Berge, Ledang, Magnusson and Bjerkeng
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The Inner Oslofjord
Berge, Ledang, Magnusson, Bjerkeng
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Recreation playground for 1 mill: Swimming, Boating etc.
60 N !
Haakon Thaulow
6. oktober 2011
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Outer fjord: Mostly non-urban
The Oslofjord – Large contrasts
Inner fjord: Urban area
Berge, Ledang, Magnusson, Bjerkeng 20. november 2013
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The Inner Oslo fjord (inside the Drøbak sill): • Area: 192 mill. m2 • Volume: 9288 mill m3 • Volume above 20 m:36 % of total volume • Volume below 20 m: 64 % of total volume • Tidal amplitude: 14 cm • Average freshwater input: 25 m3/s • Surface salinity variation: 20-30
Bathymetry of the Inner Oslofjord.
Berge, Ledang, Magnusson, Bjerkeng
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Oxygen conditions in the Inner Oslofjord 2012/2013.
Depth (m)
Depth (m)
Depth (m)
Berge, Ledang, Magnusson, Bjerkeng
20. november 2013
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Calculated water reneweal in the whole Inner Oslofjord below 20 m depth.
No calculations
Berge, Ledang, Magnusson, Bjerkeng
20. november 2013
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Vestfjorden
Bunnefjorden
Forfatter
20. november 2013
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Oxygen variations in deep water 1990-2012
Berge, Ledang, Magnusson, Bjerkeng
20. november 2013
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Total discharges of Nitrogen and Phosphorous from land to the Inner Oslofjord.
Berge, Ledang, Magnusson, Bjerkeng
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Copper and Zink in sediments Bunnefjorden High levels: 1960-1975
Forfatter
20. november 2013
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Conditions in 1950-ties, 60-ties and 70-ties were very bad ! • Sewage: local disposal with minimum treatment • Floating debris, garbage from overflows • Excessive algae growth – not clear water • Anoxic conditions in deep water due to algae mass decay
• Recreation during summer, beaches in inner fjord «abandoned» Forfatter
20. november 2013
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Discarges related to the human population is the main source for N and P Berge, Ledang, Magnusson, Bjerkeng
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sewage treatment plants and tunnel systems. Discharges at 50 m depth.
Berge, Ledang, Magnusson, Bjerkeng
Antrophogenic discharges of Nitrogen and Phosphorous to the Inner Oslofjord. 180
6000
P-Menneskeskapt N-Menneskeskapt
160
5000
120
4000
100 3000 80
60
2000
40 1000 20
0
0 År
Berge, Ledang, Magnusson, Bjerkeng
Nitrogen (tonn)
Phosphorous (tonn)
140
Winter observations of Tot-P in The Vestfjord and in The Bunnefjord. The Vestf jord (Dk1) 0-8 meters depth. Winter time (December-Februar)
The Bunnef jord (Ep1) 0-8 meters depth. Winter time (December-Februar)
90
90 Mean v alue Mean v alue
80 70
Mean v alue
± standard error
Mean v alue
80 70
Very bad
60
Very bad
60 Bad
40 Less good 30
10
Bad
50
Good
Tot-P (µg/l)
Tot-P (µg/l)
50
20
± standard error
40 Less good 30 Good
20
Very good
Very good
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1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012
0 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012
0
Y ear
Y ear
Improvement over time !
Berge, Ledang, Magnusson, Bjerkeng
«Clean and clear water with fish and shrimps we can eat»
Secchi depth development
Forfatter
20. november 2013
20
Semi decadal developement from 1973 to 2010 with 2012 Each sub row in a column equals one meter secchi depth.
2.16 3.39 3.95 4.39 5.24
3.00 Oslo 4.44 4.84 5.14 6.36
2.68 3.60 4.05 4.52 5.69
2.95 4.03 4.30 4.91 6.05
Ap2
Sandvika
Oslo
Each sub row in a column equals 1 µg/l.
8.40 6.00 3.01 2.57 3.00
18.00 9.60 5.27 2.92 3.80
2.57 ***
Aq3 11.90 7.00 4.41 2.08 3.60
Sandvika
Bn1
Bl4
9.70 6.60 3.61 1.82 2.90
Bn1
Bl4
Ap2
Cq1
4.12 5.16 5.40 5.71 6.70
5.60 4.40 2.61 1.93 2.60
3.51 4.99 5.13 5.57 6.96
Dk1
8.50 5.00 3.25 1.62 2.10
Dk1
Ep1
Ep1
+ (secchi depth)
Cq1
Secchi depth (m) mean values june-august 8.00
- (Chl –a)
8.00 1973-19828.00 8.00 1983-19908.00
Chlorophyll -a (µg/l) mean values june-august
0.00 1991-2001 0.00 0.00
Increased area with >1% ligh from 1973-82 til 19912001:
2002-2010 0.00
(map base: www.gislink.no)
0.00 2012 Null Maks
8.1*106m2 or 1350 football stadiums Drøbak
Drøbak
(Map base: www.gislink.no)
Berge, Ledang, Magnusson, Bjerkeng
20. november 2013
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Areas for trawling prawns (Pandalus borealis) in the Inner Oslofjord - around 1906 (Source: Wollebæk, 1906).
Berge, Ledang, Magnusson, Bjerkeng
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Number of individuals/100 m3
Prawns (Pandalus borealis) in the deep water in the Inner Oslofjord 1 mg/ O
350
2
300 250 200 150 100
50 0 0
1
2
3
4
5
6
Oxygern (ml/L) in bottom water
Berge, Ledang, Magnusson, Bjerkeng
20. november 2013
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Generally higher concentrations of contaminants in fish (cod liver) from the Inner fjord than from the outer part the Oslofjord PCB-7 Torsk liver 36B Færder area
Trend: / I
1800
µg/kg(v.v.)
1600 1400 1200 1000 800 600 400 200 0 1989
1994
1999
2004
PCB-7 Torsk liver 30B Indre Oslofjord
2009
Trend: / III
4500
µg/kg(v.v.)
4000 3500 3000 2500 2000 1500 1000 500 0 1989
1994
1999
Berge, Ledang, Magnusson, Bjerkeng
2004
2009
20. november 2013
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Status for soft bottom macrofauna 2009
Improvements: Good benthic quality status is not achieved at most localities in the Inner Oslofjord
Berge, Ledang, Magnusson, Bjerkeng
20. november 2013
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Increase in connection to treatment plants
Population Growth
Forfatter
20. november 2013
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Increased temperature Vestfjorden deep waters
Berge, Ledang, Magnusson and Bjerkeng
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More frequent and heavier hourly rainfalls - -
Forfatter
20. november 2013
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August precipitation - - - -
Berge, Ledang, Magnusson and Bjerkeng
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Status • The Oslo-fjord i clean- but not clean enough! Not all environmental conditions are satisfactory. • Capasity at large treatment plants exceeded • Increasing stormwater overflow episodes also in the summer season: recommendations to avoid swimming • Oxygen situation detoriating; depending on increased discharges, rainfall and wind • Increased demand for clean water in the inner harbour areas the «Fjord City» • Water Framework Directive – a new driver for new abatement measures Berge, Ledang, Magnusson and Bjerkeng
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sewage treatment plants and tunnel systems. Discharges at 50 m depth.
Berge, Ledang, Magnusson, Bjerkeng
Bekkelaget treatment plant to Capasity to be extendet 550
Bekkelaget ra. Årlig tilrenning /forurensningstilførsel som PE (personekvivalenter)
Optimaliseringsprosjekter 2011-12
500
Sum tiltak 86,5 mill kr,
450
Utvidelse Bekkelaget renseanlegg Etter KS2:
P50 2 350 mill. kr. P85 2 660 mill. kr.
1000 pe
400
350
tilknytt…
Tilkobling Midgardsormen
300
Dimensjonerende kapasitet, etter oppgradering
250
Dimensjonerende kapasitet, opprinnelig
200
VEAS
• I 2020 27% increase • 0,7 mill p.e.
«Sewage, inleaking water and rain water at VEAS 2010» 5
4
3
Mill m3 pr uke 2
1
0
Snitt to tørreste uker 2010
Snitt to våteste uker 2010
Overvann pga nedbør Fremmedvann (innlekket drikkevann, sigevann) "Ekte" avløpsvann (180 l/p*d)
Året 2010
«The Fjord City»
Forfatter
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Goals for the Oslo fjord Goal relevant to
Goal element
Recreation – outdoor activities
Acsess, estetics, bathing water quality
Commercial Fishing and Catch (prawns)
Good –ecology , micropollutans ,stock management
Water Framwork Directive
Good ecological status Good chemical status - Chl a - Lower algae growt limit - Bottom fauna - O2 and Secchi dept/sediment s are Berge, Ledang, Magnusson and Bjerkeng supporting criteria
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Oslo fjord and the WFD • Not good ecological status because of micropollutants and chemical status in sediments • Recreation relevant criteria; good status • Natural anoxic conditions in deep waters in Bunnefjorden and other deep water pockets • WDF – back to near «natural conditions» • Less focus on deep water oxygen conditions, more on recreational criteria - - ?
Berge, Ledang, Magnusson and Bjerkeng
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Strategy -measures • Increased capasity treatment plants • Upgrading/rehabilitation of sewers • Good stormwater management-separation sewage/stormwater,treatment • Outlets from treatment plants and large overflows in deep water • Water saving • Micropollutants – control at sources • Warning system city-near beaches • Fish stock management Berge, Ledang, Magnusson and Bjerkeng
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Good Water Management IWRM • Knowledgebased • Problemdriven • Solution-oriented
Haakon Thaulow
6. oktober 2011
39
Thank you for your attention
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