Phase 1 and 2 geo-environmental site investigation projects have recently been completed in the Liverpool area. Examples of two recently completed projects are described below.
Project – Callington Close, Huyton, Liverpool
Client – Langtree Homes Ltd
A desk study and initial site investigation, completed by another consultant, indicated the presence of Made Ground over the site. Following a response from Liverpool City Council, The Land Consultancy Limited were commissioned to excavate trial pits across this 0.7Ha site to determine whether and to what extent remedial measures were to protect end users of the site from any contamination present.
Samples taken for contamination testing indicated that the ashy Made Ground contained determinand concentrations above screening concentrations published for the protection of human health in a residential with plant uptake setting – the site was to be developed out with housing.
Remedial measures undertaken to protect end users included the removal of the ashy fill and installation of a 'clean' capping layer in garden areas. Method statements for undertaking this work were submitted and approved by the council. The remedial measures were verified on site by The Land Consultancy Limited and validation reports for each plot were submitted to the council and approved.
Project: Napps Way, Childwall, Liverpool
Client – Confidential
The Land Consultancy Limited was commissioned to undertake a Phase 1 geo-environmental desk study and Phase 2 site investigation on a property comprising of derelict and landscaped ground in the Childwall district of east Liverpool. Residential housing was proposed on this site.
The desk study identified the potential for Made Ground to be present beneath the site as well as peaty natural soils and weak sands and clays. Subsequent targeted trial pitting and windowless sampling site investigation works indicated that remedial measures to protect end users of the site from contamination were generally not required; gas monitoring indicated that gas protection measures did not have to be installed into the proposed houses. Foundations were advised to be supported on mini piles and/or on vibro improved ground.
Full scale soakaway tests undertaken within several trial pits suggested that the ground was unlikely to be suitable for the construction of soakaways.