landfill

• Sites:

  • Abandoned quarries 
  • Sand 
  • Gravel 
  • Clay pits 
• Issues:

  • Underlying rock may be permeable from joints and bedding planes or faults and the water table is close to the surface 
• • Limestone quarries 
  • Sand pits 
  • Clay pits
• Leachate:

  • Rainwater dissolves soluble minerals 
  • Can be acidic and dissolve rock below landfill 
  • Can contain toxic elements and form a plum of pollution 
• Many old landfills were made without an impermeable liner to prevent leakage. 
• Landfills are designed so leachates are contained and then collected for treatment. Contamination should not occur. 
• Liners are impermeable to prevent leachate release. 

  • Clay 
  • Plastic 
• Grouting:

  • Drill holes into rock and pump liquid through them
  • Reducing porosity of rock 
• Caps:

  • When landfills are full they are sealed 
  • Cap must be same material as liner 
  • Cap keeps rainwater out and limits leachate formation 
• Leachates are drained into a sump where it can be used. Any methane formed is collected and removed. 
• Buildings on old landfills are prone to subsidence, weight causes compaction of buried waste. Signs include cracks. 
• Noise:

  • Some landfill sites only take pre-compacted waste to limit heavy vehicles and noise pollution 
• Dust:

  • Landfill is covered topsoil at the end of each day
  • Dust generated from soil in dry weather 
  • Sprayed with water to reduce dust 
• Odours:

  • Bad smell 
  • Spraying waste with essential oils to improve smell 
  • Deodorant guns 
• Vermin:

  • Seagulls are a problem
  • Birds or prey to scare them away 
  • Rats and insects can be controlled 
• Wind:

  • Litter blows in the wind 
  • Fences to trap litter
• Alternatives:

  • Recycling 
  • Incineration 
• Storage of toxic waste:

  • Salt mines in cheshire can store a variety of things 
  • Official documents 
  • Toxic waste - dry form (no liquid waste is allowed)
  • 50,000 year safety range - impermeable