A TRIP ROUND THE SITE BEFORE THE DOME

In 1997 a society from the north arranged a trip round the Greenwich Peninsula to see the works on-going to remediate the site and build the Dome.  The following notes were written up after the event by one of the participants.

 PLEASE REMEMBER THAT THESE ARE NOTES TAKEN BY SOMEONE ON A COACH TRIP ROUND THE SITE  FROM MEMORY – THEY ARE NOT AN AUTHORATATIVE ACCOUNT BY AN OFFICAL PARTICPANT OR A CONTRACTOR AND ARE NOT NECESSARILY WHAT ACTUALLY HAPPENED. THEY DO, HOWEVER,  GIVE AN IMPRESSION OF THE SITE.

GREENWICH PENINSULA DEVELOPMENT. By English Partnerships

Notes on the project team’s presentation.

Original proposals to retrospective planning brief in 1980s

1992 Planning consent for revised masterplan after intervention by Michael Heseltine

Jubilee Line brought back south of the river by amendment of Bill in Parliament

  1. Better ground for train marshalling
  2. £25m from British Gas [Hansard]

3rd Blackwall Tunnel affirmed

1993 Reports proposing national Millennium Exhibition at Greenwich (incidence of any lottery) Greenwich eventually selected in later Millennium competition.

English Partnerships involved summer 1996

£147 ½ m of infrastructure in the next 2 years

Acquire freehold June/February 1997 from British Gas of whole Peninsula except industries on the west side. Long term renewal irrespective of Millennium Festival. (This followed British Gas’s statutory remediation. English Partnerships now to do development remediation.

Lead consultants W.S.Atkins with sub contractors including Richard Rogers master planners.

Refinements of master plan currently ignoring continued existence of the Millennium Dome.

18 separate development remediation contracts. Starting with the Dome site – first segments handed over in June. ( third of site) Piling able to start day after government announcement confirming the project.

See English Partnerships ‘The Millennium Riverbank Experience” . Some parts set back to become salt marsh/ reed bed.  Planted stepped terraces rather than vertical piling

Constraints of highways and utilities

Power supply in new tunnel from north side of the river 40MW capacity (including 10MW for the exhibition).

Gas main relocated – just started £27m

Water supply under regeneration – may include pipe jacking

A102M Northern Gateway Junction – new roundabout and four lane widening

Replacement of Horn Lane as distributor road

Outcome of Public Enquiry expected (fast track of four weeks to decision)

Question – How is the regeneration being recorded?? For use and reassurance of future developers

  1. Site investigation records
  2. Statutory remediation – including built records and test data. ‘Health and Safety’ file handed over to English Partnerships.
  3. ‘As built’ records of capping layers, etc. And records of tests etc . in development remediation.

Each contract has outturn survey and formal handover to succeeding contractor.

Not on Global Information Systems (too early)

  1. Will be similar handover to successive developer

Question – Local reactions

Pleased but worried about future traffic

Exhibition will be car free

Question – Extent of breaking out

Foundations being broken to 1m below formation to allow for services, etc.

Hot spots of contamination being dealt with, as found.

Capping layers being suited to end users

Coach park will be solid paved, so no capping.

Removal of 200,000 t in each of two phases of statutory remediation and an equivalent quantity removed subsequently.

Transport

Rail congested and trips limited

Road used for disposal to 10 different tips in the south east at contractors discretion

(?? Illegible) material via private river wharves

Exempted from land fill tax

Each consignment fully audited

Quantity of material to each tip agreed with HM Customs and Excise

Dutch guidelines about what must be taken off site based on statistical sampling of soil which is stock piled and retested.

Quantitative and qualitative risk assessment

Retesting of cleansed material.

In situ remediation taking longer period of time than available.

————————————

Statutory remediation was aimed at protecting environmental receptors only assuming no site development or public access.

All monitored by the Environment Agency and the London Borough of Greenwich who receive results of all monitoring.

———————————————–

No changes after tender without a Control Order

Contract is ICE 6 with client amendments to fixed price lump sum with most risks lumped onto contractors.

  • Premium found to be quite small. Contractors now experienced in the site and price has come down. (but second and third bidders are within 5%)
  • Outturn price certainly essential for this project
  • Premium at 5 – 6% without contingencies
  • Tenderers offered as much information as is available but not many take this up.
  • 4 weeks to bid and 3 weeks to award
  • Contracts £1m to £5m
  • Demolition of jetty will be £3/4m (programmed Sept –Feb 1999)

Contaminated land work £20m including capping

Statutory decontamination was also £20m.

Disposal costs of waste are the largest

£30m/3 for low grade, free of tax

£50-60m/3 for high grade waste, free of tax

Going away to Kent, Bedfordshire, etc

None came forward with river transport

Relative economies of different sites not the concern of the client

——————

Contingencies for inflation and 10% for extras

£55m on south 1/3 of site outside the Millennium site additional to the £147 ½ m for the Millennium site.

A Charitable Trust will be endowed with a sinking fund to repair the river walls and it will levy a service charge for maintenance of open spaces, etc.

 Notes on tour of Greenwich Gasworks remediation site

The tour of the site was by vehicle with photos taken through the window

Driver/guide was working on the statutory remediation by British Gas followed by the development remediation by English Partnerships this year.

  1. Millennium Dome site. The north end of the Peninsula had a large tar works. Huge tar tanks 30m x 8m full of tar mixed with rubble, replaced with London clay.  Soil was remediated by 300 well points, first subjected to vacuuming to remove volatiles followed by 16 weeks of bio remediation using air blowing. 90% of volatiles removed. Handed over to Dome contractors in three stages June to August 1997.
  2. Dome masts all erected. Bigger than they look. Ventilator stack of 2nd Blackwall Tunnel will peep out of the surface of membrane. Founded on driven piles (except close to the Jubilee Line).
  3. River Wall. Renewed April – September 1997. Sheet piles and grab irons to mainly stepped ‘ecological’ profile. Will incorporate salt marsh plants.
  4. Jubilee Line Station. Curvaceous roof over transport interchange, being clad. Long slot for station box was excavated across the Peninsula just north of the gas works jetty and parallel to its railway approaches. Contiguous bored piles. Space above will be public open space.

Ground was 5m of made ground. Alluvial clays, peats and Terrace gravels. London clay and WRB, surface falling to north.

  1. Gas Works site. Had mass concrete piers to gravel/bedrock. (for walls??) and mass concrete rafts 2 – 3 m thick. (for plant?) crushed for hardcore.  Top metre removed and reclaimed. (The Millpond was deepened into a cooling pond come settling pond in the 1950s. Contained 4m of silt in thin layers, difficult to dig, contaminated with tars),  Jetty awaiting demolition.
  2. Coalite site. Large mounds of earth, largely from the Jubilee Line excavation being placed as capping layer – sandy clay being compacted in layers.   Soil washing plant about to be dismantled. Handled 70,000m 3. Conveyors, rotary washers and screens. Fine filter cake for disposal was 20 – 30% of original soil – coarse particles returned to site after stock piling and testing. There was a water plant to clean the washing water.
  3. South site. C19th to late C20th domestic rubbish
  4. Site south of Bugsby’s Way, partly playing fields. Was remediated some years ago

Return to Gas Works

Return to Dome

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