Download 3. London Gateway Port Project ,DI, Brett

Soil Treatment Workshop
11 June 2014
London Gateway Port Project
Beneficial use of dredged material for aggregates
DEME: creating land for the future
Member of the DEME Group
Katie Read
DEME: creating land for the future
Derek Knight
Member of the DEME Group
London Gateway Port Project
• Dredging, Reclamation and
Marine Design & Build Works.
• Start: March 2010.
• Completion: Early 2014.
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Dredging the Navigational Channel
•Length: 100 km
•Width: 300 m
•Depth: -14.5 to -17.0 m CD
•Volume: c. 30M m³
•Material: Silty sand, sand, gravel
and London Clay
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Reclamation
Pre works 2009
May 2012
SeptSept
2010 2010
April 2013
April 2011
Feb 2014
Beneficial Use
• Significant volumes material.
• Material sometimes used on the project
itself.
• Frequently not all sediment suitable.
• Other engineering projects or environmental
schemes may not be feasible as projects
often do not align.
• Disposal.
• Requirement to seek to use such material in
some beneficial way.
• Beneficial use broad societal, environmental
and financial benefits.
• However, does not incur unreasonable
levels of cost for the applicant / developer.
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The Regulations
• Waste Framework Directive / Waste Regulations
...“waste” means any substance or object which the holder discards or intends
or is required to discard...”
• Material dredged for navigational purposes classified as “waste”.
• May appear overly-bureaucratic.
• Implications of large volumes of material stockpiled on land.
• DEME, with guidance from EA, have beneficially used 3.5M tonnes as a
product with Brett Aggregates.
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Environmental Permit: Risk
Assessment – the process
SOURCE:
Sediment from the sea bed
to be dredged for navigation
INPUT:
•Sea bed sediment
•Detritus in the sediment
•Estuary Water
•
PROCESSING:
•Screening
Seperation of detritus
• Dewatering
OUTPUT:
Seperated detritus
OUTPUT:
Estuary Water and
particulates
OUTPUT:
Recovered product meeting
acceptance criteria
DESTINATION:
Recycling
DESTINATION:
Returned to estuary
DESTINATION:
Delivery to Client
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Environmental Permit: Outputs
Separated detritus
•
•
•
•
International Convention for the Prevention of Pollution from Ships (MARPOL).
DEME’s environmental management system.
Suitably competent people.
Disposed of in a certified way.
•
90% of all such waste was recycled or re-used.
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Environmental Permit: Outputs
Estuary water and particulates
Addressed in the project EIA.
Dependent on the potential impact on the environment, there could be several
possible mitigations.
Control measures can then be applied to the plant.
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Environmental Permit: Outputs
Recovered Product
In hopper
• Meeting Client’s acceptance criteria.
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Overview Cliffe
Marine operation with Jetty and c.170 acres land
Ship to shore discharge
facilities
Conveyors transferring
material to processing plant
(1.5 miles away)
Block paving plant
Rail head
Aggregate processing plant
Concrete batching plant
Cliffe - Normal Situation
•
Dredged Ballast from sea bed - English Channel & North Sea
– Ability to be selective (various licenced areas to select from)
– Historic aggregate technical data (minimal verification testing required for
Dredged Ballast to meet production needs)
– Typically carrying stock of dredged ballast of 80Kt
•
Ships
– 5Kt and 10Kt self discharge ships (small campaigns of 2-4 ships)
– Discharge capacity 3Kt per hour
– Discharge stocking area of c.50Kt
•
Material Handling
– Shovel fed via loading shovel into a reception hopper
– Moved to processing plant via conveyor belt
– C.90% directly fed to processing plant from jetty
•
Processing
– Planning for 24/7 availability. Receipts match demand and surplus stock
– Typically process in excess of 1Mt with capacity for 2Mt
Cliffe - LGP Situation
•
Dredged Ballast from sea bed – Gateway Material
– Limited ability to be selective, but material consistent with typical supplies
– Visual checks on all incoming ships for acceptance and tonnage received
reported to EA
– Verification testing on every cargo of Dredged Ballast received for
grading, oversize and shell. (Selective blending to meet customer
demand)
– Significantly higher level of spare stock holding required (c.1Mt)
•
Ships
– 10Kt self discharge ships (large campaigns 6-8 ships)
•
Material Handling
– Shovel fed via loading shovel into a reception hopper or dumper
– Move to processing plant or stock area via conveyor belt and dumper
– C.60% directly fed to processing plant to minimise Dredged Ballast stock
holding
•
Processing
– Planning for 24/7 availability. Receipts higher than immediate demand
– Processing increased to >1.2Mt
Brett Meeting The Challenge
Brett Aggregates Limited
Cliffe North Sea Terminal
Why Cliffe?
• Excellent location relative to project
• Brett has proven track record on major
infrastructure projects
• Largest storage capacity of any aggregate
producer on Thames giving flexibility to
programme
• High capacity plant on rail linked site to major
markets
• The wharf is well integrated with block factory
and ready mixed concrete plant
Cliffe meeting the
challenge
•
•
•
•
Unload vessels 3Kt per hour
Receiving and handling over 250Kt per month
Stock movement and traceability of stock
Aggregate specification check on every cargo
with grading analysis in <10 hours
• Increase production to over 1.2Mt/year
– Significant capital investment required to handle this
scale of operation
• Stock capacity for up to 1Mt
Stock Areas
>100Kt Jetty end
100Kt beside conveyor
>300Kt triangle
>300Kt Processing Area
Cliffe Summary
• Over 3Mt of high quality Dredged Ballast material
producing good quality aggregates for concrete (BS EN
12620)
• Visual inspections and sampling of every cargo
• Campaigns of 60-80Kt over 4 days (Discharge area
50Kt)
• Receiving more material than required for production
(over 250Kt in peak months)
• 1Mt of temporary stocking space required (critical in
delivering on our commitment)
• Project completed on schedule
• Good relationships built and smooth execution of
contract requirements
DEME’s reporting to EA
• Permit return - Confirmation of volumes.
• Monitoring results to EA – daily and
monthly.
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Conclusion:
•
•
•
3.5M T beneficially used.
Mechanism now there to help achieve better level of beneficial use from
navigational dredgings.
Mechanism for using material on other projects e.g. habitat creation.
Acknowledgements:
•
•
•
London Gateway Port Limited
Environment Agency
DEME Building Materials
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Questions?
Katie Read
DEME: creating land for the future
Derek Knight
Member of the DEME Group