Dredging in the Port of Antwerp: challenges and best pratice. Ing. Agnes Heylen Environment Manager Antwerp Port Authority

Transcription

1 Dredging in the Port of Antwerp: challenges and best pratice. Ing. Agnes Heylen Environment Manager Antwerp Port Authority

2 Port of Antwerp - intro North west Europe Distance to the sea: approximately 100 km

3 Port of Antwerp - intro ha total area ha available area for development 900 companies 8,7 million TEU container turnover 189 million tonnes cargo turnover 45 sea ships a day 168 barges a day 220 freight trains a day

4 Port of Antwerp - intro container 58% container liquid bulk 23% dry bulk 11% breakbulk 8% breakbulk dry bulk liquid bulk Total maritime traffic: 189 million tonnes in 2011 Forecast : 265 million tonnes in 2020 million tonnes Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q Q KNOT - Knowledge Transfer & Future Cooperation

5 Port of Antwerp - intro Classic port activities: storage and transshipment petro chemistry container terminals 2 shipyards Docks Right bank: tdm/year@ AMORAS Docks Left bank: only limited maintenance dredging in

6 Sedmentation: Maintenance dredging in Scheldt & docks 100 km Port of Antwerp 20 km Scheldt River + Tidal Docks, cays on Scheldt river: : 12.5 million m 3 /y 92 % of dredged material stays in Scheldt estuary 8% (sand) is used for different applications

7 2. Sedimentation Annual deposition: ~ 500,000 TDM/year Quantitative: (Soil erosion) + deposition caused by contact salty and fresh water: 80% Human activity: 19% Atmospheric deposition: 1% Quality negatively influenced by: Dumping or discharging (legal or illegal) Spillage from transhipment activities

8 2. Sedimentation Sedimentation in tidal zones Sedimentation in non-tidal zones Relocation of sediment Sedimentation of sewer disposal and spillage Locks Sedimentation in the port of Antwerp

9 2.Sedimentation Berendrechtlock Zandvlietlock Fact: sediment accumulation Cause: density flow

10 3. Dredging techniques Operational dredging activities: river Scheldt: Flemish authority docks: port authority with own fleet

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14 4. Disposal techniques Dumping in water Underwater cell (wet dumping) Sediment Dumping in the waterway Shore dumping (wet dumping) Separation and mechanical dewatering Non-process-related reuse: - Landscaping - Land restoration (Controlled) dumping (dry dumping) Process-related reuse: mainly for construction material

15 4.1. Dumping underwater Delwaide dock underwater cell Dumping cost: approx. 8 /m³ or 16 /TDS Capacity: 3,100,000 m³ or TDS Environmental permit: Permitted untill 2011 Filled up since July 2007

16 4.1. Delwaide dock underwater cell

17 End: dumping in Delwaide dock underwater cell => Start: dumping in Churchill dock underwater cell Delwaide dock: 3 mio. m³ Churchill dock: 2 mio. m³ Building Dumping Today

18 4.3. Dumping on land Zandvliet shore dumping Shore dump 1a Dumping cost: approx. 3 /m³ or 4.50 /TDS Capacity: 750,000 m³ or 500,000 TDS (shore dump 1a) Environmental permit: till April 2012

19 Zandvliet shore dumping

20 Exploitation versus expansion 130 ha

21 4.4. Today pratice = AMORAS

22 Pipeline Route 30 ha Sand Separation Storage 20 ha Underwater Cell Dewatering

23 Temporary storage Constant feeding of sand extraction facility Separation of material (>8mm) Sand separation (> 63 µm) 1. Underwater storage cell 2. Sand extraction KNOT - Knowledge Transfer & Future Cooperation coarse

24 2 feeding pipes 1 pipe for returning water 4 cells of m3 1 cell = 1 week of production 3. Pipeline (4km) 4. Thickening ponds KNOT - Knowledge Transfer & Future Cooperation

25 12 membrane filter presses 16 m3 / press after squeezing Dry matter of filter cakes = % Conditioning: lime milk, FeCl3, PE Physico-chemical process Biological process Capacity 250m³/h 5. Dewatering 6. Water purification plant KNOT - Knowledge Transfer & Future Cooperation

26 30 hectares Capacity: 14,5 million TDM For 30 year (at disposal rate of m3/year) 7. Disposal site tds/y filter cakes Low sand content (95% < 63µm) KNOT - Knowledge Transfer & Future Cooperation DM 60% - 65%

27 rainwater Run-off purificationsystem Consolidation water filtercakes Sand (dranaige) Consolidation water Run-off purificationsystem Consolidation water (historical)dredged material groundwater

28 4.4. Today pratice = AMORAS Environmental-Ecological Aspects Environmental performant installation: Soil: use of films/drainage on the disposal site Soil: historical clay barriere on the disposal site (cocoon syndrome) Air: treatment at the source no disturbing smell (suction capacity: m³/h) Noise: closed buildings Studies about re-using the filter cakes (VAMORAS) Residual heat of nearby incenerator is used for central heating of buildings and in the future for water purification plant Research on possibilities of installation windmills

29 4.4. Today pratice = AMORAS Environmental-Ecological Aspects Creation of a nature reserve Opstalvalleigebied (phase 1): Compensation measures for disappearing of Zandwinningspond In 2008 created 3 waterpools, 2 cane fields, 16m high buffer dam Compensation monitoring in 2009: OK

30 4.4. Today pratice = AMORAS Cooperation Partners: Opdrachtgever: Vlaamse Overheid Departement Mobiliteit en Openbare Werken Afdeling Maritieme Toegang Stakeholder: Gemeentelijk Havenbedrijf Antwerpen Aannemer: THV Jan De Nul - Dredging International (DEME), Envisan en DEC

31 4.4. Today pratice = AMORAS Finances Assigned amount: 482 million (incl. VAT, construction costs, finance costs, exploitation costs) Phase 1 Construction: 118 million (incl. VAT) Phase 2 Exploitation 27 million / yr. (incl. VAT) (of which 5 million /year 70 /tdm - 35 /M3 IN SITU

32 5. Reuse = VAMORAS A flexible installation A well monitored process Result = filtercakes = an alternative raw material Possibilities of AMORAS Light weight aggregates Concrete & mortar (filler) KNOT - Knowledge Transfer & Future Cooperation Demands for reuse Bricks Infrastructur e (bulk use)

33 5. Reuse = VAMORAS Goals - 10% substitution of natural clay for bricks - 10% 50% substitution of natural clay for light weight aggregates - Use as filler (fine fraction, 100% dry matter) for concrete & mortar - Bulk use in infrastructure works KNOT - Knowledge Transfer & Future Cooperation

34 5. Reuse = VAMORAS current state Concentration of pollutants is not a bottleneck for reuse Laboratory tests show that the physical properties are appropriate for different applications. But some (shrink, pressure strength, plasticity,...) are not perfect. Composition of the sediment seems constant o o High chlorine and sulphur concentrations (thermal processes air emissions Cl) Dry matter content of dewatered sediment (DM +- 65%) is not high enough for some applications Most technical limitations can be overcome by adjusting the proces at AMORAS or post treatment. Regulatory framework and economic feasibility and certification : to be investigated KNOT - Knowledge Transfer & Future Cooperation

35 The waste of today is the raw material of tomorrow Therefore the industry of materials has to be aware and start to act in this way On this matter a sustainable long term solution for dredged sediment is feasible

36 6. Sediment quality development Trend monitoring 2002 and 2010: 57 locations on the right bank 15 locations on the left bank 50 locations nearby harbour activities

37 6.1. Sediment quality development (program 1) Method: Van Veengrapp 4 graps for 1 analysis GPS Analyses: of physical parameters of chemical parameters Based on own licenses Based on European / Flemish standards

38 6.2. Sediment quality development (program 2) ~ 130 samples/year for m³ since 1996 Frequently dredged zones 2 campaigns a year Not frequently dredged zones 1 campaign a zone Number of samples based on: - m² to dredge - m³ to dredge Van Veengrapp Cores! -> difficult

39 6.3. Monitoring programs results (1) TBT concentration (mg/kg DS) Except: 3 PoA-zone ,5 PoA-zone R2 = 0,0233 Lineair (Reeks2) 2 1,5 1 0, year Mineral oil GHA-zone concentration (mg/kg DS) 3000 GHA-zone Polynoom (Reeks2) Polynoom (GHA-zone 3134) Linear 2 R = R = year

40 6.3. Monitoring programs results (2) 2. Historical pollution Left bank right bank South north

41 2010 Crit vrij gebruik bodem Crit owc Churchilldok Locatie 2010 Location Amoras crit 2 inert afval URS16 URS13 URS10 URS07 URS04 URS01 GHA52 GHA49 GHA46 GHA43 GHA40 GHA37 Lead Lood GHA GHA31 GHA28 GHA25 GHA22 GHA19 GHA16 GHA13 0 GHA GHA GHA mg/kgds 500 GHA01 URS16 URS13 URS10 URS07 URS04 URS01 GHA52 GHA49 GHA46 GHA43 GHA40 GHA37 GHA34 GHA31 GHA28 GHA25 GHA22 GHA19 GHA16 GHA13 GHA10 GHA07 GHA04 GHA01 mg/kgds 6.4. Monitoring programs results (3) 3. Relation between concentration and leaching is not clear Lead leaching 0, ,5 0,4 0,3 0,2 0,1 0

42 6.4. Monitoring programs results (4) Bottleneck cfr. European waste directive (inert waste): Chlorides and sulfates antimony (Sb) leaching mineral oil

43 6.4. Monitoring programs results (5) 1. Historical passive comparable with other ports 2. Quality-actions: Contingency plan (actions, communication and responsabilities in case of oilspills) Set up of specific harbour regulation for those activities that are not covered by other regulations (mobile shipyards, ) Advising on new environmental licences concession agreements -soilremediation Set up of environmental friendly aspects in tenders Monitoring of turbidity 3. Trend monitoring every five years to see evolutions remains important 4. Port of Antwerp = frequent monitoring comparing to other European ports one European approach! 5. Coring remains difficult in silty material

44 6.5. Scientific research: sediments in relation to waterquality 1. Chemical approach => bottlenecks for some pollutants in some locations (historical passive) 2. Biological approach => bottlenecks based on chronic and accute ecotox tests? First results => No accute/chronic toxicity except for some algea

45 6.6. Case study: dredging and risk based approach => turbidity monitoring Dredging project planned in 2012 in a zone with an historical passive (ship yard) dredging activity of m3 dredged material Still, polluted sediments will remain on place no environmental, ecological or human risk only risk of dispersion of polluted sediments => intensive monitoring of turbidity in order to controle sediment movements. Ship movements and their influence on turbidity are taken into account.

46 Situation before dredging

47 Situation after dredging

48 Monitoring setup turbidity - With small boat / fixed points Multiple depths (most 1m 5m above bottom) Before, during, after dredging Multiparametersonde (turbidity, oxygen) Suspended solids (#) Chemical parameters (#)

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