In-situ chemical treatment remediates contaminated land by injecting reactive chemicals directly into the ground to neutralise, oxidise, or stabilise pollutants. Treatment chemicals such as permanganate, persulphate, and lime can be hazardous to workers if handled incorrectly. The injection process also generates heat, gas, and pressure that must be controlled. This talk covers the safety requirements for in-situ chemical remediation on UK sites.
Key Hazards
Chemical burns from contact with concentrated treatment reagents
Toxic vapour release from chemical reactions with ground contaminants
Injection pressure causing ground heave or uncontrolled fluid migration
Exothermic reactions generating heat and gas during treatment injection
Control Measures
Review the COSHH assessment and safety data sheet for every treatment chemical before use.
Wear chemical-resistant gloves, goggles, coveralls, and RPE specified in the COSHH assessment.
Mix treatment chemicals in a designated bunded area away from watercourses and site drainage.
Monitor the atmosphere for volatile organic compounds and reaction gases during injection.
Control injection pressures to prevent ground heave, surface breakout, and fluid migration.
Ensure emergency eyewash and safety shower facilities are available at the mixing area.
Brief all operatives on the specific chemicals, reaction products, and emergency procedures.
Restrict access to the treatment zone during active injection to trained and authorised personnel.
Record all chemical quantities, injection pressures, and monitoring data in the remediation log.
Remember
Wear the full chemical PPE specified in the COSHH assessment during all handling and injection
Monitor the atmosphere for vapours and reaction gases throughout the injection process
Mix chemicals in a bunded area away from watercourses and site drainage systems
Control injection pressures to prevent ground heave and uncontrolled fluid movement
Emergency eyewash and safety shower must be available at the chemical mixing area