Phase one – desk study & walkover survey

Walkover survey

Before any development begins, A F Howland Associates recommends conducting a phase one desk study report and walkover survey. This initial stage is considered best practice for identifying potential contamination and ensuring that issues not directly tied to current site use aren’t overlooked. This includes:

Data review

• Examination of geological and hydrological maps, regulatory records (e.g. local authority, environment agency), historical ordnance survey maps, and anecdotal evidence.
• Identification of potential hazards, including ground instability, landfill activities, and past or current contaminative uses.

Walkover survey

• On-site inspection to confirm present conditions and correlate visible features with documented historical activities.

Preliminary conceptual model

• Compilation of findings into a conceptual framework, using the source-pathway-receptor principle (PPS23) to establish contamination risks.
• Determines whether a phase two intrusive investigation is necessary based on the identified potential for contamination.