Phase 2 - Intrusive Investigation

Land Contamination Specialist

Phase 2 Intrusive Investigation

A Phase 2 intrusive survey is the second stage in the investigation of potentially contaminated ground and is only carried out if the Phase 1 Desktop Study and Walkover Survey suggests that contaminants may be present and have a potential to cause harm.

Selected soil, and possibly water samples may be taken, and a log of the ground conditions encountered. These samples are tested by an accredited laboratory to quantify the levels of the suspected contaminants. Testing is generally done to UKAS or MCERTS certification.

We do not have expensive drilling rigs or gas sampling equipment to keep working and we will not be asking for their use unless it is necessary.

No ground is ever free of all contamination: Some contamination occurs naturally; some accumulates over the years and some is the result of a single significant event. The level of acceptable contamination is influenced by the end use of the site and its ability to cause harm to human health.

All samples (soils, water, gasses/vapours) will then be sent to a UKAS or MCERTS accredited laboratory for testing. These results will then be interpreted as part of the Phase 2 Intrusive Investigation Report, forming a part of the Conceptual Site Model for your site. Should the Phase 2 identify negligible contamination then (upon agreement with your Local Authority), your development can progress. Should the Phase 2 identify contamination on site, the process will then move on to the Phase 3 Remediation Strategy and Verification stage.

The second Phase can be broken down into two main categories, water/ground contamination and ground gas/vapour conditions.

Water/Ground

This involves attending site and taking samples from trial pits excavated by hand or machine, or boreholes formed by drilling rigs. Sampling can be targeted, random or a mixture of both to fully characterise  the whole site. Samples will be tested for a range of contaminants or for a specific contaminant, i.e. should the Phase 1 have only identified possible lead contamination on site from an on-site or nearby industry, then lead will be the main criterion we shall test for. However, often we will test for a generic suite of contaminants for completeness.

Ground Gasses or Vapours

Often, sampling of either (or both) ground gasses and vapours will be required on site. This can be due to natural deposits (such as underlying peat), human deposits (landfill etc) or oils/fuels (vapours). This involves the formation of boreholes within which a ground gas/water or vapour monitoring point will be installed. The site will then be visited a number of times over the course of a few months, with readings taken during each visit. These results will then undergo statistical analysis to prove/disprove ground gas/vapour generation or groundwater contamination.

Analysis

All samples (soils, water, gassess/vapours) will then be sent to a UKAS or MCERTS accredited laboratory for testing. These results will then be interpreted as part of the Phase 2 Intrusive Investigation Report, forming a part of the Conceptual Site Model for your site. Should the Phase 2 identify negligible contamination, then (upon agreement with your Local Authority), your development can progress. Should the Phase 2 identify contamination on site, the process will then move on to the Phase 3 Remediation Strategy and Verification stage.




Contact
Contact Castledine Environmental

Email us:      info@castledineenvironmental.co.uk
Phone us:    01509 880399
WhatsApp:   01509 880399
Image
© 2024, Castledine Environmental