Who can carry out a Phase 2 ground investigation

A Phase 2 ground investigation has to be designed, supervised, interpreted and signed by someone the local planning authority will accept as suitably qualified and experienced. That phrase comes from BS 10175 and from the Planning Practice Guidance on land affected by contamination, and it is the test the contaminated land officer applies when the report lands on their desk. Phase 2 contaminated land competence is judged on the report and the team behind it rather than on a single certificate, which is why two reports on similar sites can get very different receptions.

A Phase 2 report is also the document that carries the most liability of anything in a planning pack. It says the ground is safe for the proposed use. Get it wrong and the consequences arrive years later, in the hands of people who bought houses on the strength of it.

Why the officer asks who wrote it

Planning policy places responsibility for securing safe development on the developer or landowner, and the local planning authority has to be satisfied that the site can be made suitable for its proposed use. The officer is not equipped to re-run your risk assessment. What they can do is check the conceptual site model, the sampling rationale, the laboratory certificates and the qualifications of the people who produced them.

A report that reads as a data dump with no interpretation, or one where the author cannot be identified, gets sent back. So does one where the sampling pattern shows no relationship to the Phase 1 findings.

What suitably qualified and experienced means in practice

There is no statutory register of contaminated land assessors. Competence is demonstrated through a combination of qualifications, chartered status, membership of a relevant body and demonstrable experience of similar sites, and the officer weighs those together.

The markers councils look for:

• A named author with chartered status in a relevant discipline, such as chartered geologist, chartered environmentalist, chartered scientist or chartered engineer.
• Membership of a body whose remit covers land condition, and evidence of continuing professional development in risk assessment.
• Registration on a specialist scheme for land condition or ground engineering, where the assessment of competence has already been made by peers.
• Project experience on comparable ground conditions and comparable end uses, because a residential end use with private gardens is a different problem from a warehouse with a concrete slab.

None of these alone is sufficient. A chartered geologist who has never designed a residential ground gas assessment is not the right author for one.

Fieldwork supervision and desk interpretation are different jobs

This is the split that goes wrong most often. The drilling contractor is not the assessor. The person logging the arisings on site should be a geotechnical or environmental specialist working to the logging conventions in the site investigation standards, and their logs are the primary record everything else rests on.

Three practical requirements for the fieldwork:

1. Continuous supervision by a competent logger, not spot visits to a self-recording contractor.
2. Sampling decisions made on site against the conceptual site model, with the authority to add locations where the ground does not match the prediction.
3. Ground gas monitoring visits spread across a range of falling atmospheric pressure conditions, because a set of visits taken in settled high pressure tells you very little.

The interpretation then belongs to the risk assessor, who takes the logs, the laboratory results and the monitoring data and tests them against the conceptual site model. Where those two roles sit with the same person on a small site, say so in the report.

Laboratory accreditation and why it is checked

Soil and water analysis should come from a laboratory holding accreditation for the specific determinands being reported, not simply accreditation in general. The certificates should be appended in full, with sample identifiers that match the logs, dates that fall within the holding times for each analysis, and the limits of detection stated.

A common failing is a laboratory report where the detection limit for a contaminant sits above the assessment criterion being used. The result reads as not detected and proves nothing. Our note on accredited laboratories for soil and water analysis covers what to check on the certificate before it goes in the appendix.

Registers, chartership and what they actually prove

Registers of specialists in land condition and of ground engineering professionals exist because the industry needed a way to signal competence that a client could check. They work as a filter rather than a guarantee. What a register tells you is that a panel has reviewed that individual's experience against defined criteria at a point in time.

What it does not tell you is whether the individual has done your kind of site. Ask for two recent examples with the same end use and similar ground, and ask who will actually sign the report rather than who is in the pitch.

Peer review before submission

On anything other than a simple site, an internal technical review by a second assessor is worth the day it takes. The reviewer should check the conceptual site model against the data, confirm that every potential pollutant linkage identified in Phase 1 has been addressed or discounted with reasons, and test whether the remediation strategy follows from the findings.

Where a scheme is contentious or the end use is sensitive, an independent review commissioned by the developer before submission costs less than the delay of a refusal and a resubmission. Councils sometimes ask for one and charge the cost to the applicant, so having already done it is the stronger position.

Where the liability sits

The consultant's duty runs to the client under the appointment, and the limit of liability and the professional indemnity cover are set there. Read them. A cap set at the fee level on a report supporting 80 houses is not meaningful cover.

Collateral warranties or reliance letters extend the duty to funders, purchasers and the eventual homeowners' warranty provider, and they have to be agreed at appointment rather than negotiated afterwards. Where the consultant is novated to the contractor, the reliance position changes, which we look at in novating a consultant appointment to the contractor.

Statutory liability is separate. Part IIA of the Environmental Protection Act 1990 attaches to the person who caused or knowingly permitted the contamination, and in its absence to the current owner or occupier, regardless of what any consultant's appointment says.

Getting the commission right

Write the brief around the Phase 1 findings. A Phase 2 scope that was copied from another site is visible to the officer within a page, and it is usually visible to the consultant too, who will price it as instructed rather than as needed.

Where ground engineering and contamination overlap, a single combined investigation avoids two mobilisations, and a Geotechnical Assessment can share boreholes with the environmental sampling. The contamination reporting itself sits in the contaminated land assessment, which covers both the Phase 1 desk study and the Phase 2 intrusive stage.

Land contamination assessment is a report type where a suitably qualified and competent professional is legally expected: the NPPF places responsibility on the developer and authorities expect investigation carried out in accordance with the relevant British Standard by suitably qualified and experienced persons. An AI-assisted draft is a starting point for that professional rather than a substitute for them. Reviewers listed in the PlanScope professional directory can review and sign off a draft where the report type allows it.

This is general guidance, not legal advice. Check the position with your local planning authority or a qualified professional before relying on it. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval. For specialist technical reports, qualified professional input may be required.