Soil contamination and its impacts on construction works

The actual or suspected presence of contaminants in soil and water has significant implications.

Disturbing and handling contaminated materials issues

• whether excavation of materials might increase movement of contaminants
• whether intrusive works may allow contamination to migrate into deeper ground particularly through layers of low permeability materials such as clay
• whether removal of low permeability surfacing such as concrete and tarmac will allow more infiltration into contaminated materials below
• the removal of any structures containing contaminated materials such as oils.

Design issues

• whether the design introduces risks to human health or the environment
• whether the design allows for material excavated on site to be used
• sulphate contamination in the ground, as this can weaken concrete
• piling through contaminated ground, as this can create a route for pollutants to enter groundwater.
• avoiding discharges of surface water into contaminated areas.

Waste management issues

• whether material excavated on site can be used in the design and needs additional measures
• how and where excavated material can be disposed of off-site
• whether excavated material will need to be treated before it can be disposed of or used
• the cost of treating or disposing of contaminated materials.

Water issues

• rainwater that is allowed to pass though stockpiles of contaminated material can carry pollutants into the ground below
• any water that you remove from excavations in contaminated ground could itself be contaminated, and this may require treatment or will affect how you must dispose of it.

Health and safety issues

• the preparation of your health and safety risk assessments, and consequent work methods, COSHH assessments and the sort of Personal Protective Equipment that you will require need to take into account any contamination present.

Health and Safety Executive: Control of Substances Hazardous to Health (COSHH) guidance

HSENI: COSHH

SEE ALSO: Dealing with contaminated land,

Control of water pollution from construction sites