PSI Vs. DSI – Site Investigations Broken Down

Two common approaches are followed across the globe for site investigation PSI (Preliminary Site Investigation) and DSI (Detailed Site Investigation). These investigation methods are vital in assessing the environmental condition and potential risks associated with the proposed land. Several geotechnical companies in Sydney offer PSI vs DSI – Site Investigation services. Let's break down these investigations to understand their purposes and differences.

Preliminary Site Investigation (PSI)

PSI is a standard method and an initial step to gather general information about a site and identify potential environmental risks. Its primary objective is to know whether further investigation is required for this land. If it is necessary, geotechnical engineers apply the second method, which is called DSI.

PSI is the most common method applied to review historical records, conduct site visits, and collect available data from various sources such as regulatory agencies and public records. Regarding technical elements, PSI will conduct visual inspections, interview stakeholders, and collect samples to evaluate the presence of contaminants or potential pollution sources.

Almost every preliminary site investigations company in Australia applies these two methods. If the report shows potential environmental risks, DSI is inevitable.

Detailed Site Investigation (DSI)

DSI is a more comprehensive and detailed investigation conducted by geotechnical engineers when potential environmental risks have been identified during the PSI or when a site is known to have a history of contamination. The objective is to assess the nature and extent of contamination and evaluate the potential impact on human health and the environment. This is the primary concern for detailed Site investigations companies to assess the site.

DSI is a systematic approach to getting detailed information about the site, including soil, groundwater, surface water, and air quality assessments. It aims to identify the source, migration pathways, and extent of contamination. Regarding technical aspects, DSI employs soil and groundwater sampling, laboratory analysis, geophysical surveys, and advanced site characterization methods like drilling and soil vapor extraction.

The output of a DSI is a detailed assessment of the site contamination, risk characterization, and recommendations for remediation or further investigation if necessary. Geotechnical engineering companies like BHM geotechnical have experienced and skilled teams to help you regarding PSI and DSI.

Key Differences

PSI determines the need for further investigation, while DSI focuses on the detailed assessment of contamination and its potential impact. PSI gives a general overview, whereas DSI is more comprehensive, involving in-depth sampling, analysis, and judgment.

PSI gives only limited sampling and visual inspections, while the DSI method is for advanced techniques to evaluate site contamination. PSI results in a summary report, while DSI generates detailed information with comprehensive findings and recommendations.

In simple terms, PSI serves as an initial screening tool to identify potential environmental risks. On the other hand, DSI is a more extensive investigation to assess and characterize contamination. Both investigations are essential in evaluating site conditions and determining the need for further action, such as remediation or monitoring.