Contaminated land remediation on Merseyside using in-situ chemical oxidation
Client: Housing developer
Location: Wirral, Merseyside
Contract period: 10 weeks
Telluric Land Remediation proposed in-situ chemical oxidation to remediate a localised, 15.0 m deep, hydrocarbon impacted groundwater plume on land previously used as a tank farm. Remediation of the localised plume was required to protect a site boundary watercourse identified in a controlled waters risk assessment as being at significant risk.
Following detailed discussions with the regulators the remediation works involved the installation of 24 distribution points accompanied by several dedicated monitoring boreholes to observe and monitor progress. Controlled volumes of modified Fenton’s reagent were dispensed to the distribution wells via temporary pipework installed at the site. On site testing of the adjacent watercourse was undertaken during injection works to monitor for any potential impact the remediation may have on the watercourse.
Analytical results for groundwater samples recovered from the treatment area after injection and following a rebound check phase indicated total petroleum hydrocarbons concentrations of <10µg/l with aliphatic and aromatic fractions below detection limits.
- Development of remediation strategy
- Investigation and protection of adjacent watercourse
- In situ treatment of hydrocarbon impacted groundwater plume
- Injection of 36,000 litres of chemical oxidant
- Installation of distribution and groundwater monitoring boreholes
- Decomissioning of injection boreholes and injection infrastructure
- Compilation of validation report
Remediation targets were achieved to the satisfaction of the regulator with the site handed back to the developer with all planning conditions relating to contaminated groundwater being discharged.
A pdf version of this groundwater remediation case study is available here.