White Young Green Environmental

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• White Young Green Environmental
• Environmental Aspects of Non nuclear related
  clean up during decommissioning
• 13th October 2006
• Dr. Phil Studds

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Contaminated Land - Background

• Applying non nuclear experience to
  decommissioning
• Non-nuclear contaminants account for 80-90 of
  remediation (site area basis)
• Contaminants associated with former MoD sites
• Hydrocarbons - fuel, lubricants and solvents.
• Explosives - unusual contamination e.g. chemical
  weapon residues
• Other contaminants - asbestos, metals and general
  waste from workshops, storage and operational
  facilities.
• Recent issues
• LA / EA more involved with nuclear sites
  (decommissioning process) and will concentrate on
  non-nuclear issues since more familiar
• Current waste tips created at nuclear sites used
  to accommodate non-nuclear waste

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Background cont.

• Contaminated land hot topics
• Soil guideline values (SGVs) how to determine
  land as contaminated
• Waste Licensing Issues in Brownfield
  Reclamation
• Issues associated with Incorrect Waste
  Classification

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Part IIa Definition of Contaminated Land

• Is it nuclear or non-nuclear?
• Previously radioactive contamination was excluded
  from the Part IIA regime but this changed on 20th
  January 2006
• However, nuclear sites were excluded. They fall
  within the Nuclear Installations Act 1965 (NIA)
• The Radioactive Contaminated Land (Enabling
  Powers) (England) Regulations 2005
• Environmental Protection Act 1990 (amended 1995
  Part IIa)
• Part IIa - definition of contaminated land is
  intended to embody the concept of risk assessment
  and it is defined as
• Any land which appears to the local authority in
  whose area it is situated to be in such a
  condition, by reason of substances in, on or
  under the land that,
• significant harm is being caused or there is a
  significant possibility of significant harm
  (SPOSH) being caused or
• pollution of controlled waters is being, or is
  likely to be caused.

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Pollutant Linkage
For a risk of pollution or environmental harm to
occur as a result of ground contamination a
significant source pathway receptor
pollutant linkage must be established. A
pollutant linkage requires
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Non-nuclear Contaminants

• Metals
• PAHs (Poly-Aromatic Hydrocarbons)
• Chlorinated Solvents (VOCs and SVOCs)
• Phenols
• TPH (Total Petroleum Hydrocarbons)
• BTEX Petroleum Range Organics
• Diesel Range Organics
• Mineral Oils / Lubricants
• Fuel Oils
• Kerosene / Paraffin

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Key Stage of Risk Assessment

• 3 key stages to assess significant risk
• Preliminary Risk Assessment (typically
  qualitative) - development of the conceptual site
  model and establishing a pollutant linkage
• Generic Quantitative Risk Assessment - comparison
  of contaminant concentrations to generic
  screening values e.g. SGVs and
• Detailed Quantitative Risk Assessment -
  evaluating the significance of the
  source-pathway-receptor pollutant linkage using
  site-specific data and simple commercially
  available analytical models.

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Conceptual Model S-P-R Pollutant Linkages
Volatilisation
Direct contact
Gas
Dust
Contaminated sediments
Contaminated Fill
Surface run-off
Residential use
Leaching and infiltration
Gas migration
Contaminated soils
Volatilisation
Volatilisation
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Generic Risk Assessment

• Generic Screening values are compared to Soil and
  Groundwater results, e.g. CLEA SGVs for soils and
  EQS or UK Drinking water standard for waters.

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Recent Guidance Re. SGVs CLEA

• Defra warned Local Authorities to stop
  determining sites as contaminated land simply
  because contaminant concentrations exceeded SGVs.
  
• CLAN 02/05 Sept 2005
• Non-exceedance indicates acceptable
  contamination conditions, exceedance does not
  indicate unacceptable conditions and in
  particular does not indicate significant
  possibility of significant harm (SPOSH).  
• CLAN 04/06 April 2006
• No new SGV or Toxicology reports for substances
  will be issued until SPOSH resolved.
• Key Question how far above the SGV would the
  soil concentration have to be to meet the
  unacceptable intake test.

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The problem with SGVs CLEA

• The key messages in CLANs 02/05 and 04/06 -
  current technical guidance is not capable of
  supporting the statutory requirements of Part2A
• Gaps in guidance severely restricting
  practitioners attempts to determine land as
  contaminated land under Part 2A, particularly
  noticeable where exceedances of SGVs have been
  observed in the gardens at existing residential
  property.
• SGVs define the level of minimum risk - need for
  a higher value to be derived for each contaminant
  which represents the "unacceptable intake" level
  of contamination which is in accord with the
  definition of the condition of SPOSH which is
  necessary for determination.

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Quantitative Risk Assessment Models

• EA RD Publication 20 Methodology for the
  derivation of remedial targets for soil and
  groundwater to protect water resources
• RAM Risk Assessment Model (based on RD P20)
• ConSim (www.consim.co.uk)
• RBCA Risk Based Corrective Action
• Risc Work Bench (BP Risk)
• CLEA Contaminated Land Exposure
• Assessment Model (EA DEFRA),
• CLR Reports 7, 8, 9 10

Ref Benchmarking and Guidance on the Comparison
of Selected Groundwater Risk-Assessment Models.
National Groundwater Contaminated Land Centre
NC/00/14. 2001.
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Remedial Technologies routinely applied include
the following

• In Situ Bio-remediation (Natural attenuation and
  degradation)
• Ex situ bioremediation (biopiles landfarming)
• In Situ Reactive Walls (funnel and gate systems)
• Stabilisation Technologies
• Soil Washing

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Remediation - General Considerations

• Break the pollutant linkage either by source
  reduction or break the pathway
• Application of these technologies is site and
  contaminant specific
• Implementation of any remedial action requires
  planning, focused investigations
• Relevant data collection
• Risk assessments to determine clean up targets
• Feasibility (pilot) tests to demonstrate
  technical application

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Waste Licensing Issues Associated with
Remediation

• Licensing of Remediation
• Mobile Treatment License
• Replaced Mobile Plant Licenses in April 2006
• Contaminated soil needing treatment is a waste as
  excavated therefore permitting needed
• Single License with a Deployment Form for each
  site
• Covers 15 treatment processes (e.g.
  bio-remediation, soil washing, screening)
• Intended to be simpler than MPLs encourage
  sustainable remediation

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Importance of correct waste classification

• White Young Green carries out hazard assessment
  using most likely speciated form and the results
  typically conclude that made ground soil would be
  classified as non-hazardous.
• For work with British Waterways specialist
  testing (ecotoxicity and XRD) supported the
  assumptions made.
• White Young Green has successfully adopted this
  approach for BW with dealings with SEPA and for
  another client with dealings with the EA.
• Cost savings for the BW Glasgow site were in the
  order of 500,000
• Same approach has been used for development sites
  which have had significant cost savings for the
  developer

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Additional Environmental considerations

• Asbestos presence/disposal in structures and
  the ground
• EA/Natural England will further emphasise
  ecological considerations in future work
• Noise/Air Quality issues during decommissioning
• Land Use/space for creation of new inert
  facilities for disposal of decommissioning waste
  preparation of EIAs
• Sustainability
• Public perception