Phase 2 Ground Investigation

A Phase 2 Ground Investigation forms part of Stage 2 within the Land Contamination Risk Management (LCRM) process, following completion of a Phase 1 Desk Study and Risk Assessment.

At this stage, intrusive investigation is undertaken to validate and refine the Conceptual Site Model (CSM) developed in Stage 1 by collecting site-specific ground and environmental data. This allows identified risks and pollutant linkages to be confirmed, revised, or ruled out, supporting progression through planning.

Key Objectives

Refine the Conceptual Site Model (CSM)

• Confirm or update source–pathway–receptor linkages identified during Stage 1.

Characterise ground conditions

• Determine soil and rock profiles, including made ground, natural strata, and groundwater conditions.

Assess contamination risks

• Sample and analyse soils, groundwater, and ground gas to evaluate risks to human health, controlled waters, and the environment.

Derive geotechnical parameters

• Obtain data on strength, compressibility, and bearing capacity to inform foundation and earthwork design.

Support risk evaluation

• Determine whether pollutant linkages are complete and whether mitigation or remediation is required.

Typical Methods

• Trial pits and boreholes for ground profiling and sampling
• Window sampling for shallow ground investigation
• In-situ testing (e.g., SPT, CBR) for geotechnical parameters
• Laboratory testing for soil classification, strength, and chemical analysis
• Groundwater and gas monitoring where risks are identified

Role in LCRM

Phase 2 provides the factual evidence required to move from preliminary risk assessment to detailed evaluation. The results are used to:

• Confirm or refine the CSM
• Quantify risks identified in Stage 1
• Inform whether remediation is required
• Support discharge of planning conditions and progression to Stage 3 (remediation strategy)