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Risk Assessment: Working with Contaminated Ground

Document Information

Field Value
Document Reference RA22
Issue Number 2
Issue Date 1 June 2026
Next Review 1 June 2027
Prepared By Sean Ashton
Approved By Aaron Mason, Director

Risk Assessment Table

Activity/Process Hazard Who/What Affected Existing Controls Pre-Control Risk (S/L/R) New Controls Required Post-Control Risk (S/L/R)
Pre-construction site investigation Failure to identify existing contamination before works commence Site personnel exposed to unknown contaminants
• Local environment affected by mobilization
• Public exposed to contaminants
• Desktop studies of site history conducted
• Preliminary site investigation with soil sampling
• Laboratory analysis where contamination suspected
• Consultation with regulatory authorities
• Review of ground investigation reports
• Ground penetrating radar surveys
• Results incorporated into project planning
4/3/12 (High) • Establish minimum site investigation requirements based on site history HSQE
• Develop central database of contaminated sites HSQE
• Consider specialist contaminated land consultants for high-risk sites Project Manager at planning stage
4/2/8 (Moderate)
Excavation in contaminated areas Exposure to hazardous substances through inhalation, ingestion, or skin contact
• Mobilization of contaminants
Site personnel suffer health effects
• Environmental contamination
• Public exposure to mobilized contaminants
• Site-specific risk assessments developed
• Appropriate PPE provided
• Dust suppression measures
• Air monitoring for volatile contaminants
• Controlled excavation techniques
• Work rotation to limit exposure
• Exclusion zones established
• Decontamination facilities provided
5/3/15 (High) • Enhanced training on contaminated ground hazards HSQE
• Consider permit to work system for contaminated ground operations HSQE
• Cross reference with Method Statement 2.23
5/3/15 (High)
Discovery of unexpected contamination Unplanned exposure to hazardous substances
• Inappropriate handling
• Spread of contamination
Site personnel health effects
• Environmental contamination from uncontrolled spread
• Training to recognize contamination signs
• Stop work policy if suspected
• Supervisors immediately notified
• Temporary covering of suspect material
• Sampling for analysis
• Work resumes only after identification
• Emergency spill kits available
• Toolbox talks on recognition
4/4/16 (High) • Consider field testing kits for preliminary identification Environmental Manager, within 3 months 4/3/12 (High)
Storage and handling of contaminated materials Cross-contamination of clean areas
• Leaching from stored materials
• Wind-blown dust
Site personnel exposure during handling
• Environmental contamination
• Adjacent land/water contamination
• Contaminated materials segregated
• Designated storage with containment
• Impermeable membranes under stockpiles
• Stockpiles covered
• Runoff control measures
• Minimal material handling
• Damping down in dry conditions
• Clear marking of storage areas
• Vehicle wheel washing
4/3/12 (High) • Additional training on contaminated material handling for supervisors HSQE 4/2/8 (Moderate)
Transportation of contaminated materials Spillage during transport
• Cross-contamination of vehicles
• Inappropriate disposal
Transport personnel exposure
• Environmental spillage
• Public highway contamination
• Licensed waste carriers only
• Appropriate waste classification
• Waste transfer notes completed
• Vehicles sheeted/sealed
• Vehicle cleanliness inspected
• Designated loading areas
• Supervised loading
• Planned transport routes
• Emergency response procedures
4/3/12 (High) • Specific training for drivers transporting contaminated materials HSQE 4/2/8 (Moderate)
Working with asbestos-contaminated soils Exposure to asbestos fibers during soil disturbance Site personnel develop asbestos-related diseases
• Public exposed to airborne fibers
• Specific asbestos risk assessments
• Personnel with asbestos awareness training only
• Enhanced dust suppression
• Air monitoring during works
• RPE (minimum FFP3) and disposable coveralls
• Decontamination facilities with showers
• Controlled excavation techniques
• Immediate covering/damping of exposed soils
5/3/15 (High) • Enhanced training on asbestos in soils Specialized providers, within 2 months
• Consider licensed asbestos contractors for high-risk work Operations Director per project
• Cross reference with Method Statement 3.10
5/2/10 (High)
Personal decontamination Inadequate decontamination leading to prolonged exposure
• Cross-contamination
• Off-site transfer
Site personnel prolonged exposure
• Family exposure from contaminated clothing
• Site facilities contamination
• Appropriate decontamination facilities
• PPE removal procedures established
• Clean/dirty areas demarcated
• Hand washing enforced
• Boot wash stations at exits
• Disposable coveralls for high contamination
• Separate PPE storage
• Regular welfare facility cleaning
• No contaminated clothing home
4/3/12 (High) • Enhanced training on decontamination procedures HSQE
• Consider portable shower facilities for high-risk work SLT
4/2/8 (Moderate)
Health surveillance Undetected health effects from exposure
• Lack of early intervention
Site personnel develop undetected health conditions • Health surveillance programs established
• Pre-employment health screening
• Exposure records maintained
• Regular health checks for carcinogen exposure
• Personnel informed of symptoms
• Occupational health services available
• Biological monitoring where appropriate
4/3/12 (High) • Comprehensive health surveillance program for water industry contaminants Occupational Health, within 3 months
• Information sessions on long-term health effects HSQE
• Consider biological monitoring for significant exposure Occupational Health, within 4 months
4/2/8 (Moderate)

Key:

  • S = Severity (1-5 scale)
  • L = Likelihood (1-5 scale)
  • R = Risk Rating (S × L)
  • Risk Levels:
    • Low (1-3)
    • Moderate (4-8)
    • High (9-15)
    • Very High (16-25)