REM/Specific/TBT-REM-009

Made Ground and Unknown Fill Hazards

Remediation & Contaminated Land › Specific › Made Ground and Unknown Fill Hazards

Presenter		Project
Location		Date

Made ground is material placed by humans rather than natural geological deposits, found on many brownfield sites.
Unknown fill can contain anything: concrete, brick, metal, timber, asbestos, chemicals, and domestic waste.
Excavating in made ground encounters unpredictable material that changes behaviour with every bucket load.
Asbestos-containing materials are commonly found in made ground from demolished buildings and industrial sites.
Ground gases including methane and carbon dioxide generate from decomposing organic material in old landfill.
Chemical contamination from previous industrial use may be concentrated in pockets within the fill material.
Made ground has unpredictable strength; excavation sides can collapse without warning in loose fill.
Sharp and hazardous objects including glass, metal, and needles are hidden within fill material.
COSHH 2002 requires assessment of contamination risks before any work disturbing made ground.
A desk study and site investigation should characterise the fill before major excavation begins.

Contamination exposure	Workers excavating in made ground contact asbestos, chemicals, and biological hazards hidden in the fill material.
Ground gas risk	Methane and CO2 from decomposing fill accumulate in excavations, creating explosion and asphyxiation hazards.
Collapse risk	Made ground has no natural structure. Excavation sides in loose fill collapse suddenly and without warning.

Don't

Review the desk study and site investigation data before excavating made ground.
Monitor for ground gases in all excavations through made ground or former landfill.
Wear gloves, safety boots, and RPE when handling potentially contaminated fill.
Support excavation sides in made ground; do not rely on the fill to stand unsupported.
Stop work and report immediately if suspected asbestos is found in the fill.
Classify and dispose of contaminated excavated material as controlled or hazardous waste.
Brief all operatives on the types of contamination expected from the site investigation.
Use an exclusion zone around the excavation face where contaminated material is exposed.
Wash hands and remove contaminated clothing before eating, drinking, or leaving site.
Record all unexpected contamination finds and report them to the site management.

DON'T excavate made ground without reviewing the site investigation data first.
DON'T assume made ground is clean because it looks like natural soil.
DON'T enter excavations in made ground without gas monitoring equipment running.
DON'T handle suspected asbestos found in fill without trained specialist support.
DON'T leave excavation sides unsupported in loose or variable fill material.
DON'T dispose of excavated made ground without waste classification testing.
DON'T ignore unusual smells, colours, or textures in the excavated material.
DON'T eat, drink, or smoke near excavations in potentially contaminated ground.
DON'T pick through fill material with bare hands looking for objects.
DON'T spread contaminated fill across clean areas of the site for use as fill.

See also: Contaminated Land Safety Awareness | Ground Gas Monitoring

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