Case Study: Pear Tree Farm, Brereton Green, Cheshire
Client: Wharfe Rural Planning
Services: Infiltration testing, BRE 365 soakaway testing, BS6297 soil infiltration testing, trial pitting, groundwater investigation
Location: Brereton Green, Cheshire
Project summary & client purpose:
Earth Environmental & Geotechnical was commissioned to undertake infiltration testing at Pear Tree Farm, Brereton Green, on behalf of Wharfe Rural Planning, to support the proposed development of the site.
The investigation was undertaken to provide robust, site-specific data on ground conditions, groundwater and infiltration performance. The findings were required to inform the site’s drainage strategy, ensuring appropriate drainage solutions could be selected at an early stage while supporting the planning process.
Our services:
Our team completed a programme of machine and hand-excavated trial pits across the site, undertaking BRE 365 soakaway testing alongside BS6297 soil infiltration testing. Groundwater investigations were also carried out to establish groundwater levels and assess their influence on drainage design.
Ground conditions were logged by our engineers throughout the investigation, with infiltration testing completed in accordance with current industry standards. The results were presented in a concise technical report, providing practical recommendations to support the client’s drainage design and planning requirements.
The challenges:
Ground conditions varied across the site, with sandy topsoil overlying predominantly gravelly sands, alongside localised stiff clay horizons and groundwater encountered within one investigation location.
The investigation also identified differing infiltration performance between machine-excavated and hand-excavated test locations. While infiltration testing for proposed soakaways indicated that the underlying ground had insufficient permeability in several areas, shallow soil infiltration testing demonstrated more favourable conditions. This highlighted the importance of undertaking comprehensive testing to ensure the most appropriate drainage solution could be selected.
Results:
The investigation provided the client with clear, site-specific evidence to inform the proposed drainage strategy. Testing confirmed that infiltration-based soakaways would not be suitable within the machine-excavated test locations due to low permeability, while soil infiltration testing demonstrated acceptable performance for alternative drainage approaches.
By identifying groundwater conditions and variations in ground permeability at an early stage, the findings enabled the design team to progress with confidence, reducing uncertainty and helping to avoid costly redesigns later in the project.
