Hydrogeology evidence and technical documents Hydrogeology evidence and technical documents
Produced by the Freedom of Information officeAuthored by Infrastructure and Environment and published on
14 November 2025.Prepared internally, no external costs.
Request 759780187
Under the Freedom of Information (Jersey) Law 2011, please provide the following information held.
Hydrogeology
Full hydrogeological assessment(s), models and assumptions (drawdown, radius of influence, recharge).
Borehole logs, groundwater level data, pump test data, piezometer locations, and monitoring results.
Dewatering assessment and method statements (construction & contingency).
Groundwater quality data (incl. PFAS, nitrates, chlorides/sulfates), sampling plans, and lab reports
Structural & geotechnical
Anti-flotation calculations, uplift vs dead-load, and chosen restraint system (tension piles/anchors).
Pile specifications (diameter, depth, number, design loads), base slab design, settlement predictions.
Ground risk register and geotechnical design reports (GDR/GDA).
Runway/Infrastructure interface
Any runway/taxiway impact assessments, vibration and settlement risk assessments, and monitoring plans agreed with Ports of Jersey. Correspondence or MOUs with Jersey Water and Airport Operations regarding protection of assets.
Environmental management
Construction Environmental Management Plan (CEMP); flood/storm exceedance strategy; spill/overflow modelling and public reporting protocols.
Long-term odour/H₂S and corrosion protection strategy; maintenance/life-cycle plan
Governance & decisions
Officer/ministerial decision records, briefing notes, and ministerial meeting minutes relevant to approval
Response
Hydrogeology
Information relating to Hydrogeology is available on www.gov.je using the links below, therefore Article 23 of the Freedom of Information (Jersey) Law 2011 has been applied.
Planning Application Documents
Planning Application Detail
PFAS in Jersey
However, detail behind the Models and assumptions would require extraction and manipulation of data to produce new information. A Scheduled Public Authority (SPA) is not required to manipulate and create new data sets; therefore, Article 3 of the Freedom of Information (Jersey) Law 2011 therefore applies.
Structural & geotechnical
Article 35 (Formulation and Development of Policies) of the Freedom of Information (Jersey) Law 2011 has been applied to the release of information relating to Anti-flotation calculations, uplift vs dead-load, chosen restraint system (tension piles/anchors) and Pile specifications.
Article 35 is a qualified exemption; therefore, a public interest test has been applied and is shown at the end of this response.
The SPA does not hold a Ground risk register or geotechnical design reports (GDR/GDA); therefore, Article 3 of the Freedom of Information (Jersey) Law 2011 applies.
Runway/Infrastructure interface
Runway/taxiway impact assessments, vibration and settlement risk assessments, and monitoring plans have been withheld under Article 38 (a) of the Freedom of Information (Jersey) Law 2011.
Article 38 is a qualified exemption; therefore, a public interest test has been applied and is shown at the end of this response.
You may also wish to send your request to Ports of Jersey in writing to:
ask@ports.je
or by post to:
Ports of Jersey, St Peter, Jersey, JE1 1BY
It should be noted that Ports of Jersey is not a Scheduled Public Authority (SPA) under the Freedom of Information (Jersey) Law 2011, therefore, they are not required to respond.
Correspondence or MOUs with Jersey Water and Airport Operations regarding protection of assets is partially exempt under Article 23 of the Freedom of Information (Jersey) Law 2011 as the information is accessible on www.gov.je using the link below:
Planning Application Documents
Planning Application Detail
Article 35 (Formulation and Development of Policies) of the Freedom of Information (Jersey) Law 2011 has been applied to any additional information.
Article 35 is a qualified exemption; therefore, a public interest test has been applied and is shown at the end of this response.
Environmental management
The Construction Environmental Management Plan (CEMP) is exempt under Article 23 of the Freedom of Information (Jersey) Law 2011 as the information is accessible on www.gov.je using the link below:
Planning Application Documents
Planning Application Detail
The SPA does not hold any additional information; therefore Article 3 of the Freedom of Information (Jersey) Law 2011 applies. Long-term odour/H₂S and corrosion protection strategy; maintenance/life-cycle plan is exempt under Article 35 (Formulation and Development of Policies) of the Freedom of Information (Jersey) Law 2011.
Article 35 is a qualified exemption; therefore, a public interest test has been applied and is shown at the end of this response.
Governance & decisions
Officer/ministerial decision records, briefing notes, and ministerial meeting minutes is partially exempt under Article 23 of the Freedom of Information (Jersey) Law 2011 as the information is accessible on www.gov.je using the link below:
Planning Application Documents
Planning Application Detail
Furthermore, information has been withheld Article 33(b) (Commercial Interests) of the Freedom of Information (Jersey) Law 2011.
Article 33 is a qualified exemption; therefore, a public interest test has been applied and is shown at the end of this response.
Any additional information is not held by the SPA; therefore Article 3 of the Freedom of Information (Jersey) Law 2011 applies.
Articles applied
Article 3 - Meaning of “information held by a public authority”
For the purposes of this Law, information is held by a public authority if –
(a) it is held by the authority, otherwise than on behalf of another person; or
(b) it is held by another person on behalf of the authority.
Article 23 - Information accessible to applicant by other means
(1) Information is absolutely exempt information if it is reasonably available to the applicant, otherwise than under this Law, whether or not free of charge.
(2) A scheduled public authority that refuses an application for information on this ground must make reasonable efforts to inform the applicant where the applicant may obtain the information
Article 33 - Commercial interests
Information is qualified exempt information if –
(a) it constitutes a trade secret; or
(b) its disclosure would, or would be likely to, prejudice the commercial interests of a person (including the scheduled public authority holding the information).
Public interest test
In applying this article, the following considerations were taken into account.
Public interest considerations favouring disclosure
Disclosure of the information would ensure the general public are informed about the work plans related with gardening and specifically in relation to the untamed trees at the easterly end.
Disclosure of the information would support transparency and promote accountability to the general public, preventing misuse of public contracts and favouritism.
Disclosure would also promote trust in the Scheduled Public Authority (SPA) by showing openness.
Public interest considerations favouring withholding the information
The disclosure of the gardening contracts and work plans could potentially disadvantage the contractor’s and the SPA’s ability to retain commercial advantage in any future tender process.
This could also result in the SPA’s inability to secure best value for the taxpayer and this will likely prejudice the SPA as its bargaining power decreases.
Contract documents can contain proprietary methodologies, pricing structures, and operational strategies developed by the contractor. Making these public would unfairly advantage competitors and potentially reduce market participationin future tenders.
The disclosure of the work plans may result in misinformed public debate regarding any mutually agreed changes to the original work plan. Therefore, this could jeopardise the business relationship between the SPA and the contractor.
The disclosure of the work plans can invite undue interference from third parties who may misinterpret timelines or attempt to influence operational decisions, disrupting service delivery. For example, public stakeholders may react to methodologies used or maintenance schedules without understanding the technical or regulatory rationale, causing unnecessary delays or conflicts.
Technical terms, seasonal adjustments, or contingency protocols within work plans can be misunderstood by non-specialists. This may lead to misinformation and mischaracterisation of the contractor’s performance. For example, seasonal reductions in mowing frequency for environmental reasons might be wrongly interpreted as neglect or cost-cutting.
Considering all considerations above, while transparency and accountability is important, the public interest in disclosure must be weighed against potential harm caused by prejudice of the commercial interests and the risks of misinformation.
The SPA has concluded that, on balance, the risk of causing harm caused by prejudice of the commercial interests and or concerns or spreading misinformation, the public interest in maintaining the exemption outweighs the benefits disclosing the
information
Article 35 - Formulation and development of policies
Information is qualified exempt information if it relates to the formulation or development of any proposed policy by a public authority.
Public Interest test
In applying this article, the following considerations were considered.
Public interest considerations favouring disclosure
Disclosure of the information would support transparency and promote accountability to the general public, providing confirmation that the necessary discussions and assessments have taken place.
Disclosure to the public fulfils an educative role about the early stages in policy development and illustrates how the department engages with parties for this purpose.
Public interest considerations favouring withholding the information
In order to best develop policy and provide advice to Ministers, officials need a safe space in which free and frank discussion can take place – discussion of how documentation is presented and provided is considered as integral to policy development as iterations of documents are demonstrative of the policy development process.
The need for this safe space is considered at its greatest during the live stages of a policy.
The release of the information without comprehensive interpretation alongside other data could impact the general public with misinterpretation and generate misinformed debate. This would affect the ability of officials to consider and develop policy away from external pressures, and to advise Ministers appropriately.
Premature disclosure of this information may limit the willingness of parties to provide their honest views and feedback. This would hamper and harm the policy–making process not only in relation to this subject area but in respect of future policy development across wider departmental business.
Considering all considerations above, while transparency is important, the public interest in disclosure must be weighed against potential harm caused by distress or misinformation.
It should also be noted that once a policy is formulated and published, the public interest in withholding information relating to its formulation is diminished, however, the use of the exemption can be supported if it preserves sufficient freedom during the policy formulation phase to explore options without that process being hampered by some expectation of future publication.
The SPA has concluded that, on balance, the risk of causing significant concerns or spreading misinformation, the public interest in maintaining the exemption outweighs the benefits disclosing the information.
Article 38 (a) - Endangering the safety or health of individuals
Information is qualified exempt information if its disclosure would, or would be likely to –
(a) endanger the safety of an individual; or
(b) endanger the physical or mental health of an individual.
Public Interest Test
In applying this article, the following considerations were considered.
Public interest considerations favouring disclosure
Disclosure of airport runway/taxiway impact assessments, vibration and settlement risk assessments, and monitoring plans, could enhance public confidence in the management of airport safety and operational risks.
Providing access to such documents could help the public understand the nature and scale of risks managed at the airport. It could promote informed public debate about safety standards, environmental safeguards, and infrastructure planning.
Public interest considerations favouring withholding the information
The documents are likely to contain detailed information about airport layouts, vulnerabilities, and specific risk mitigation measures. Disclosure could enable individuals or groups with malicious intent to exploit weaknesses, thereby increasing the risk of harm to staff, passengers, and the public.
Risk and impact assessments often include sensitive procedural information that, if disclosed, could undermine established safety and emergency response protocols.
Disclosure could deter staff and external contractors from providing full and frank assessments in future, thereby reducing the quality of internal risk management and the effectiveness of future assessments.
Airports are part of critical national infrastructure. Sharing detailed operational or risk-related information could conflict with aviation security standards (e.g. those set by the UK Civil Aviation Authority or the European Union Aviation Safety Agency) and compromise compliance obligations.
Considering all considerations above, while transparency is important, the public interest in disclosure must be weighed against potential harm caused by distress or misinformation.
The SPA has concluded that, on balance, while there is a clear public interest in transparency regarding how the airport manages risk, this is outweighed by the public interest in maintaining safety and security. The disclosure of detailed impact and risk assessments would pose a real and significant risk to operational safety and could endanger individuals if the information were misused.
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