Site Investigations: A Simple Guide


Ever wonder how we ensure the ground beneath us is safe for building homes, commercial buildings or offices? Site investigations help us understand the condition of the land, including its soil, water, and potential contaminants. This guide will walk you through the basics of site investigations.

Why Do We Need Site Investigations?

Site investigations are crucial for:

  • Safety: Ensuring the ground can support buildings and is free from harmful substances.
  • Compliance: Meeting UK laws and regulations.
  • Environmental Protection: Protecting local ecosystems from contamination.
  • Cost-Efficiency: Avoiding unexpected problems and costs during construction.

Key Steps in a Site Investigation

1. Preliminary Assessment

  • Desk Study: Gather existing information about the site. This includes maps, historical land use, and previous reports.
  • Site Visit: Conduct a walkover survey to visually inspect the site and identify any obvious issues.

2. Planning the Investigation

  • Objectives: Define what you need to discover, such as soil stability or contamination levels.
  •  Methods: Based on the site’s characteristics and the information needed, decide on the techniques and equipment to use.

3. Sampling Procedures

   – Soil Sampling:

  • Trial Pits: Small excavations that allow visual inspection and sampling of the soil layers.
  • Boreholes: Drilled holes that provide deeper samples. They’re essential for understanding sub-surface conditions.
  • Sampling Techniques: Use tools like hand augers, mechanical augers, or drilling rigs. Ensure samples are taken at various depths and locations for a comprehensive analysis.

   – Water Sampling:

  • Groundwater Monitoring Wells: Install wells to monitor and sample groundwater. This helps detect any contamination.
  • Surface Water Sampling: Collect samples from nearby rivers, lakes, or streams to assess any impact from the site.
  • Gas Sampling:
  • Soil Gas Probes: Install probes to measure gases like methane and carbon dioxide in the soil. This is crucial for sites that might have buried waste or organic material.

4. Laboratory Testing

  • Soil Tests: Analyze samples for properties such as grain size, moisture content, and contamination levels.
  • Water Tests: Check for chemical contaminants, pH levels, and other water quality indicators.
  • Gas Tests: Measure concentrations of hazardous gases.

5. Data Analysis and Reporting

  • Interpret Results: Compare the data against UK regulatory standards and guidelines.
  • Risk Assessment: Identify any potential risks to human health or the environment.
  • Report Findings: Compile a detailed report with findings, conclusions, and recommendations. This report is crucial for decision-making and ensuring compliance with regulations.

UK Laws and Regulations

  • Environmental Protection Act 1990: Requires that contaminated land be identified and remediated to prevent harm to human health and the environment.
  • Construction (Design and Management) Regulations 2015: Ensure that health and safety risks are managed throughout construction projects.
  • Building Regulations 2010: Mandate that the ground is suitable for construction and that proper measures are taken to address any issues.


Site investigations are an essential step in any construction project. They help us understand the ground conditions, identify potential hazards, and ensure compliance with UK laws and regulations. By following a systematic approach to sampling and analysis, we can make informed decisions that protect both people and the environment.

Remember, a thorough site investigation is all about being methodical and ensuring safety from the ground up! We know it might seem complicated and daunting so please get in touch if you have any questions or need further clarification on any part of the site investigation process.