Technical map of the Weser-Ems administrative area marking Oldenburg for explosive ordnance assessment and surveying by FONTANA-EOD

Explosive ordnance surveying and disposal in Emden

For project owners, planners and site management, FONTANA-EOD assesses whether earlier explosive ordnance records cover the present ground works on a changed site in Emden. Known fill, excavation and alterations are compared with the documented areas, reference levels and depths. Send complete earlier reports and current site and levels plans, identifying missing information, so that supplementary investigations can be agreed specifically before earthworks.

Records

Check the date, area investigated and result.

Ground

Identify known changes.

Construction planning

Compare the proposed areas and depths.

Discuss the documents for your projectExplosive ordnance assessment in Lower Saxony
Assess the construction project

Relate earlier records to the present ground surface

After fill, excavation or alterations, earlier depth figures may describe a different part of the ground from present plans. For your project in Emden, we therefore compare the locations, level references and scope of findings in existing explosive ordnance records. Outstanding areas are defined by specialists before the new earthworks.

Project site

Connect the site with the specific construction task

Illustration of a map with the Lower Saxony coat of arms, a tablet, hard hat and documents.

Site and existing requirements

Specify the actual project location with a site plan and the affected land parcels. Existing information, conditions and reports are assigned to this area. Emden is an independent city in Lower Saxony in the Weser-Ems administrative area. The city is responsible for explosive ordnance hazard prevention; information and existing reports are assigned to the specific site and ground works. Clearly locate projects in the city centre and central districts, Borssum, Barenburg, Uphusen or Marienwehr on the site plan. For projects in Aurich, Leer, Norden, Krummhörn, Hinte or the districts of Aurich and Leer, the bodies responsible for each project location are involved. Identify the available records and exact project address for every construction area; outside Emden, municipal responsibility depends on the municipality concerned.

Explosive ordnance assessment in Lower Saxony
Local context

Assess wartime impacts and later changes to the ground

Local starting point

The City of Emden points out that explosive ordnance must be considered before both construction of structures and ground investigations. It identifies its Environment Service as the hazard prevention authority and explains aerial photograph analysis by the state explosive ordnance disposal service. For your project, it must be assessed what the existing findings establish about the planned ground works areas. General information about the city is insufficient.

A severe air raid struck Emden on 6 September 1944. For preliminary research, available wartime aerial photographs and other historical records are related spatially to the present construction area. The historical attack must be distinguished from investigation results for the specific ground works area.

For sites subsequently built over or filled, development between the photograph date and present construction-stage conditions is also considered. Earlier property boundaries, additional structures and changed surface levels are marked on the site plan. Undocumented changes remain identifiable as uncertainties during investigation preparation. For construction projects in port and cargo handling areas, shipyards, industrial, production, storage or logistics sites, earlier uses are compared using the available records and plans. This includes routes, transport and utility areas, shore areas and access roads wherever they affect the ground works. For conversion or reconstruction, documented changes are assigned to present construction areas and depths.

The Emden City Archive documents the air raid of 6 September 1944. For historical assessment, land-use and damage information from the time is compared with the construction area affected.

Implications for construction planning

If, for example, fill was added or part of an area excavated after an analysis, the surface at the time may differ from the present surface. Compile available plans and dates for such changes. Where records are missing, this must be considered in further planning.

Working together

Distinguish the tasks of client, designers and specialist contractor

Client and operator

The client describes the project and provides the available project records. The operator adds requirements for use, access and timing. A coordinating contact brings the parties together; individual tasks remain assigned to the named parties. Before commissioning, it is clearly recorded what information is missing, who will obtain it and what decision the result is intended to prepare.

Planning and construction management

The specialist designers describe areas, depths, construction methods and changes. Site management coordinates the planned sequence with the construction contractors and agreed specialist works. Results are assigned to the respective intervention. A technical plan change is communicated early enough for its effect on the survey task to be assessed before construction. Organisational construction stage boundaries remain distinguishable from technical survey boundaries.

Specialist company and competent bodies

The private explosive ordnance specialist contractor performs the agreed investigation and documentation work. Official requirements and decisions are clarified with the respective responsible bodies. The records needed for a specific procedure depend on the location and project. The technical report documents the specialist work carried out and its area, depth and limits of conclusions. The responsible bodies make official decisions concerning subsequent groundworks.

The City of Emden identifies its Environment Service as the hazard prevention authority for explosive ordnance disposal. Lower Saxony’s explosive ordnance disposal service supports it through administrative assistance, including aerial photograph analysis and its assigned recovery and disposal tasks. The commercial specialist contractor investigates the commissioned ground volume and documents the results. Contacts, conditions, reporting channels and handover of assessed findings are agreed for the project.

Investigation task

Which specialist task comes next?

Establish the scope of findings in earlier analyses

First, the existing records are read to establish what they actually assess. A historical analysis describes a different basis from a technical survey. The assessment area, recommendations and known gaps are compared with the present plans. Where ground levels have changed, the reference conditions at the time must explicitly be included. The next commission should answer a specific unresolved question rather than merely repeat an earlier document title.

Assess historical documents

Investigate the ground volume still unresolved

An additional investigation is tailored to the ground works planned today. Which method is suitable depends on the investigation objective, depth and local conditions. Known fill or installations are considered as constraints. A noticeably different surface condition alone establishes neither suspected contamination nor the appropriate method.

Compare investigation methods
Project types

Assess ground changes for different construction tasks

Illustration: a person wearing a hard hat and holding a tablet beside a cordoned-off excavation with an excavator.

A new building on a changed site

For a new foundation, working areas and proposed depths matter alongside the building outline. If the terrain was previously raised or lowered, these changes are assigned to the present plan. Available plans should make the earlier and proposed conditions traceable. An existing report can then be related to the new construction task without inferring an investigation status from the age of the site or its previous use.

Provide specialist supervision of excavation
Illustration: two people with a tablet beside a drawing table and a survey trolley on a construction site.

Utility construction between different ground levels

A new utility may pass through several sections with different surface levels. Depth details for the beginning, end and changing sections must therefore be clearly described. Existing investigation plans are brought to the same spatial reference. A transfer chamber or deeper connection also belongs in the comparison. The utility route is treated as ground works in its own right, even if the neighbouring buildings have stood for a long time.

Specialist services and investigation tasks
Illustration: a person with survey equipment in a marked construction area; an excavator with a drilling attachment stands on the right.

Ground investigations before the main construction work

A planned borehole requires a clarified explosive ordnance investigation status even before later excavation. Provide the points with their depths and the level reference used. If borehole positions move or alternatives are proposed, these changes must also be assessed. Ground investigation findings can support further planning, but creating an investigation borehole and investigating for explosive ordnance remain different tasks. The ground works description also includes technically proposed additional paths. The survey report records which ground volume was actually investigated for drilling; the term borehole clearance is tied to this documented scope.

Understand downhole surveys
Preparation

Prepare the scope and commission together

Establish what needs to be known before commissioning the work

The commission first needs to clarify which decision is to be prepared. Does it concern an initial assessment of existing records, investigation of a specific area or further work on a finding already assessed? These tasks need different information. A general desire for safety does not yet describe an investigation scope that can be carried out. The enquiry therefore identifies the ground works, location, depth and available findings. Suitable specialist work and required results documentation are agreed on that basis. When taking over a previously used site, complete reports with associated plans and details of the terrain at the time are requested. Later earthworks and sections that cannot be assigned are identified before a new commission.

Define the specialist task

Coordinate preparatory work with the investigation

Required access and survey conditions are clarified before the site visit. This may include keeping areas clear, obtaining service information and coordinating with other trades. The method and site determine which preparations are actually needed. Changes to the surface or additional groundworks are not undertaken unilaterally simply to prepare for a survey. Their sequence is agreed with the specialist designers and responsible parties.

Clarify preparatory work in the programme

Agree a clear scope and schedule

A reliable workflow distinguishes work already clarified technically from prerequisites still outstanding. If an area will be only partly accessible, this must be taken into account when commissioning. Handover and assessment of results also need time in the construction programme. Specific coordination relates the described scope to access, records, execution conditions and the date by which a decision is needed. A tender identifies the known records, changes to the ground, access and required results documentation. Defined services are separated from tasks whose necessity can be assessed only after reviewing the documents. Sections initially blocked remain assigned to their later investigation.

Discuss the scope and schedule
Tasks at the site

These records help with comparison

01

Complete analyses and associated plans

Do not provide only a covering letter or a single coloured map. The report, associated plan, spatial limits and recommendations form the context. Check whether the area considered actually matches the proposed project and whether the records assess different areas differently.

02

Alterations and changes to the ground

Compile available plans of earlier fill, excavations or foundations. Distinguish documented information from verbal recollections or assumptions. A known surface change is relevant to planning, but alone proves neither removal nor presence of explosive ordnance.

03

Current level and depth references

State the surface or level from which the planned ground works depth is measured. If earlier records use a different ground level, mark the difference. Only this reference identifies the ground layer reached by the present ground works.

04

Existing investigation results

Earlier technical reports must be read to establish which section, depth range and conditions they covered. Later alteration does not extend those findings. In the enquiry, therefore, identify the changes known since the investigation and the records missing for them.

Project documents

Documents that establish the next step

Clearly compare terrain conditions at different dates

Dated site and levels plans, records of existing conditions and documented fill or excavations are helpful. Record which details were measured, taken from a plan or passed on only verbally. A missing survey of existing conditions is not replaced by an estimated level. The specialist planners clarify which reliable information is still needed for the next investigation step.

Show the relationship between the report and construction plan

Assign each earlier investigation to its associated section and reference level. Additional or deeper ground works should remain identifiable in the current construction plan. If soil is moved after the investigation, this change must be considered when the report is used later. Results and associated plans are therefore passed on together. After clearance work, the clearance record with the actual scope and results is added; the areas covered and their reference levels remain identifiable on the associated plans.

Construction sequence

Coordinate investigation and construction sections

Clarify the status needed before the next soil removal

If a further change to the ground surface is planned, its sequence must be coordinated with the required explosive ordnance assessment. An investigation appointment relates to the agreed site conditions. Preparatory excavation must not be silently assumed if it is itself ground works whose prerequisites remain unresolved. The planners, contractors and specialist company therefore clarify what needs to be established before each ground intervention and how the respective level reference remains documented.

Coordinate the construction phase with us

Prepare later foundation and utility works

After a completed partial investigation, its scope is compared with the following work. A new foundation type or deeper utility may affect different ground zones. Creating an access road or temporary connection can also constitute additional ground works. Site management receives the existing results together with a traceable assignment to the proposed work and outstanding areas.

Coordinate the construction phase with us
Method selection

Select methods according to the task and survey conditions

Historical records and aerial photographs

Historical aerial photograph assessment and other old records help place the basis for suspicion in its spatial context. The available images, their evidential value and the limits of the area considered matter. The absence of an identifiable indication must be distinguished from a technically surveyed ground area. The assessment is considered together with the planned intervention and other available findings. It can support the choice of a survey, but is not a measurement of the present-day subsurface or confirmation for all future works.

Understand aerial photograph assessment

Magnetometric survey

Magnetometric methods detect magnetic anomalies. Whether they can address the specific survey task depends, among other things, on the expected objects, ground conditions, interference and required survey area. Fences, utilities or existing structures may affect interpretation. A measurement signal is therefore not described as ordnance solely because of its strength. Method, interpretation and any further investigation are planned as a connected specialist task.

Understand the scope of magnetometry

Electromagnetic methods

Electromagnetic investigations may be suitable for certain metallic target objects and site conditions. Suitability is justified for the particular task, rather than inferred from equipment availability alone. Interfering installations, accessible areas and the conclusion required must also be considered. Results are documented with their location and investigation conditions. Whether a supplementary method is needed follows from the technical assessment and remains a specific project decision. TDEM records time-dependent electromagnetic responses from electrically conductive objects.

Understand electromagnetic surveying

Ground-penetrating radar

Under suitable conditions, ground-penetrating radar can provide information about subsurface structures and reflections. Ground conditions, moisture, installations and the particular investigation task affect interpretation. An anomaly is not automatically explosive ordnance, and an area without anomalies is not general evidence for arbitrary depths. The technical interpretation and limitations are documented with the commission. An investigation for other purposes is not adopted as explosive ordnance evidence without assessment. Highly conductive ground can limit its range.

GPR and limitations

Deep-ground and downhole surveys

For deeper groundworks, it may be necessary to establish whether a surface investigation can provide the required findings or another approach is needed. Preparation includes the location, depth, borehole layout and existing services. Creating access for the investigation must also be properly planned by specialists. A general depth figure or standard grid cannot replace that work. Findings remain limited to the areas actually investigated and the method used.

Prepare deep interventions

Survey during construction

If a necessary preliminary investigation cannot be completed, it is assessed whether a technically planned approach during construction is suitable. This includes coordinated investigation, interpretation and communication of findings within the planned workflow. Visual observation during excavation is not an interchangeable substitute for a necessary survey. Site management needs a clear description of when specialist work takes place, how new findings are handled and which areas remain unresolved. Where the method is suitable, each working layer is technically surveyed and assessed before controlled removal in layers. Visual checks supplement the survey. The process continues to the agreed excavation base and, where necessary, along walls or slopes; the stop signal, authority to issue instructions and reporting channels are agreed beforehand.

Agree the approach during construction
Technical assessment

Clarify missing information and further investigations

Compare aerial photograph analysis and survey report

The historical aerial photograph analysis provides information for assessing suspected contamination. It does not replace a technical investigation required where there is corresponding suspicion. Conversely, a technical survey result without a spatial reference cannot establish whether it covers the entire current construction task. It must therefore be assessed which areas, depths and questions each of the two documents covers.

Choose the method for the planned ground works

Whether a surface survey is suitable or additional methods are needed depends, among other things, on the objective, depth affected and survey conditions. Known fill and installations must be reported as constraints. Fill alone establishes neither safe conditions nor a particular investigation method.

Assess changed areas separately

If a project extends deeper or affects areas different from those documented earlier, the additional investigation needed must be defined. The specialist investigation should answer the outstanding questions about these areas and depths. Further records or preparatory work may be needed beforehand. An earlier report is sufficient only to the extent that it actually covers the current task.

Next steps

From the earlier report to a documented investigation result

01

Record the construction project and assign documents

Record the assessment date, section and conditions at the time. For the first discussion, also identify the present ground works, their locations and depths, and the planned start. The client and site management provide the available records with associated plans. Different construction and terrain conditions may coincide in Emden; the enquiry therefore already identifies which area is to be addressed next and which investigation results are needed for it.

02

Trace the records and changes

Add evidence of known alterations and changes to the ground. Earlier analyses, survey reports and official correspondence are reviewed with their appendices. Area boundaries, depth references and ground levels used are particularly important for comparison. Documented fill, excavation or altered installations are assigned to the current site plan. The review separates existing investigation results from outstanding questions. Missing appendices or unclear level information are identified specifically so that further work builds on a traceable basis.

03

Assess historical indications and aerial photographs

Historical research concerns the ground works area actually proposed. Existing analyses are considered; outstanding questions determine the need for further records or suitable wartime aerial photographs. For different periods of use, historical boundaries are compared with present plans. Identifiable indications and analysis limitations are recorded. The documented bombing of Emden forms part of the local background; investigation needs for an individual site follow from the specific findings assigned to it and the construction task.

04

Compare the construction task and select methods

Compare present areas and ground works depths with the documented scope. The investigation objective and methods are agreed on that basis. Ground structure, utilities, installations, interference and access affect the findings needed. Where fill or excavation has occurred, the level reference used must match both existing results and present plans. The specialist planners specify the areas or points to be covered and preparatory work the survey requires. The chosen scope is agreed with site management and the client.

05

Investigate the agreed area

The specialist contractor carries out the commissioned investigation. Survey grids, necessary borehole locations and access for investigation are coordinated with the area, level reference, ground works depth and local conditions. Survey data and findings are spatially referenced; inaccessible sections and interference are recorded. The work uses the agreed plan version and terrain conditions. Changes during construction are assessed for their effect on investigation. Where supervision is agreed, specialist work and construction progress are coordinated according to the agreed approach.

06

Assess findings and agree further work

The results are compared with the construction task. Anomalies, assessed findings and unresolved areas are identified separately. For confirmed explosive ordnance, recovery and further handling are agreed with the responsible bodies in accordance with Lower Saxony’s division of responsibilities. Survey conditions and method limitations feed into the specialist assessment. Where further investigation is needed, the location, depth and question to be answered are recorded. Those involved can thus distinguish existing findings from the work still required before the affected ground intervention.

07

Document results and outstanding follow-up measures

The report and its plans identify the points, areas and depths actually investigated. Survey conditions, limitations and outstanding tasks remain identifiable for the next investigation or construction activity. Where applicable, a clearance record relates the location, depth, findings and results of recovery work carried out. The evidence includes the plan version used and a traceable level reference. The report and appendices are handed over together. Later participants can then relate the findings to the associated area and compare them with changed construction records.

08

Agree supplementary work and the next ground intervention

Agree which outstanding areas and depths are to be investigated. Before the next ground intervention, it is assessed whether the existing results cover its location, depth and conditions. Changed ground levels, additional connections or further construction phases are explicitly considered. Those involved clarify necessary additions and any official requirements. The decision on the next steps is linked to the current plans and a named contact; the associated records remain available together in the project file.

Documentation

Record the location and reference level in the report

Findings and their scope

Documentation should identify the location and depth reference of the investigation together with its underlying conditions. If different conditions are compared, the information used and remaining uncertainties must be recorded. Site management must be able to understand which findings apply to the ground works now proposed and which area or depth needs further consideration. Survey data and findings are linked to their specialist assessment. Where clearance work was carried out, the corresponding clearance records and spatial references belong in the project file. Before the next construction phase, the current construction plan is compared with these results and outstanding specialist tasks.

Project responsibilities

The responsible hazard prevention authority and the state explosive ordnance disposal service carry out their respective official duties. FONTANA-EOD performs the agreed investigations and documents the results. The responsible bodies make official decisions. Other soil or ground investigation questions are assessed by the specialists responsible for them.

Working approach

How FONTANA-EOD works

Document the agreed specialist service clearly

We assess the planned groundworks against the available documents and their design revision. Before attending site, we agree with you what needs to be investigated, which areas are accessible and what findings are required. If the design or site conditions change, we check whether the agreed scope remains appropriate. The report states what was actually investigated and the limits of the findings. This allows designers and site management to see which findings they can use and where questions remain.

Discuss the investigation task

The task before the equipment

We first establish the investigation objective: which question must it answer? We then select a technically suitable method. The availability of a particular device or experience on a similar neighbouring site is not enough to justify the choice of method on its own.

Keep limitations visible

Inaccessible areas and limited conclusions are identified. They do not disappear into a total area figure. Designers and site management can then decide specifically which areas still need attention and when a suitable survey becomes possible.

Clarify changes before intervening in the ground

A new location, additional depth or different construction method is compared with previous results. A familiar project name does not replace this comparison. Feedback is provided before the affected work so that an outstanding question can be included in the sequence.

Hand over the report and plan together

The technical conclusion remains connected to its location references and appendices. A brief summary helps orientation but does not replace the documented survey scope. This basis is retained even if site management or contractors change.

Understand the results

Use technical statements for the next decision

Read results together with their scope

A statement is understandable only with its investigation task. Check the area and depth described, methods used and restrictions. A report title or single result line is insufficient. For new work, these details are compared with the current plan to establish which knowledge remains usable and which question is unresolved.

Understand investigation reports and their limitations

Use project terminology unambiguously

Document review, surveying, construction-phase specialist work and recovery are different tasks. An enquiry need not identify the correct method in advance. An accurate description of the intervention and required decision is more useful. This establishes the appropriate technical scope and prevents a general term from meaning different things in design, procurement and execution.

Understand the service scope
Design and findings

Documents for the next construction decision

Illustration: aerial photographs and maps on two screens and printed on a desk.

Historical evidence and the current design

Aerial photograph interpretation is related to the actual groundworks. Its purpose and geographical scope remain distinct from a technical investigation of the ground as it is today.

Understand aerial photograph assessment
Illustration: two people review plans and documents at a table beside a construction vehicle.

Specialist reports for site management

The findings, their locations and limitations are handed over together. This makes clear to those carrying out the work which area has been investigated and which task remains outstanding.

Assess investigation reports
Four people in orange high-visibility vests in front of two excavators on a construction site.
Person with a yellow survey cart on a footpath in front of a hedge.
Questions from planning

Questions about earlier records and changes to the ground in Emden

Is an earlier aerial photograph analysis sufficient for new construction?

That depends on its content and the planned ground works. The area assessed, findings and recommendations, and known changes must be checked. Whether supplementary technical investigations are needed follows from the specialist assessment and requirements applicable to the project.

Is an area with added fill automatically safe?

No. Added fill alone establishes neither the presence nor absence of explosive ordnance in the ground. Assess the available records of changes to the ground together with the areas and depths of the planned ground works.

Why is a depth without a level reference problematic?

It may remain unclear which surface it was measured from. If the terrain has changed, identical depth figures can describe different ground zones. Existing plans and technical reports should therefore provide traceable location and level references.

What should I do if no plans exist for an earlier alteration?

Identify the missing plans in the enquiry. The first step is to assess what can be established reliably from the other records. Necessary additions or investigations are then agreed. Missing information is not evidence that the ground is safe.

How do I report a suspicious find during ground works?

If possible explosive ordnance is found, stop work at the location immediately. Do not touch, move or expose the object further. Leave the immediate area, keep your distance and keep others away without putting yourself at risk. In Germany, notify the police immediately on 110 and follow their instructions. Inform site management and the client; internal reporting must not delay the emergency call. An enquiry form for planned construction projects is not an emergency reporting channel.

Is an older report unusable simply because of its date?

The date alone does not decide this. What matters is the findings it contains, the areas and depths covered and changes since the investigation. A complete report may remain relevant. Its applicability to the present project is assessed from its content and current plan version.

Which details determine investigation work and costs?

A current site and levels plan, type and depth of ground works, complete earlier reports and information about known changes to the ground are helpful. Also identify access and the date by which a decision is needed. Missing information or limited survey conditions may require additional coordination and preparatory work. Ground structure, metal interference, required interpretation and documentation scope also feed into agreement of the quotation.

How are conflicting level figures handled?

Mark the different figures and identify the plan source, date and reference point for each. The responsible planners must clarify which basis applies to the proposed ground works. An unresolved level difference is not resolved by adopting the more favourable figure; it remains an outstanding planning question until clarified.

Project enquiry

Discuss earlier and current plans together

Identify plan versions and changes

Describe the planned earthworks with the current spatial and level references. Add available records of earlier alterations, fill or excavations. Distinguish confirmed information from assumptions not yet clarified. Coordination also depends on which ground works are planned first. Identify maximum ground works depths, construction time windows and specialist work already commissioned.

Send complete reports with their appendices

Provide earlier aerial photograph analyses and technical investigation reports, including maps and recommendations. A single results line explains neither the investigated area nor its conditions. Identify the people who can obtain missing plans of existing conditions and the date by which the construction planners need reliable findings. Add official correspondence, conditions, utility plans and ground investigation records or records of existing structures. Identify areas not yet accessible.

Project enquiry

Have your project assessed

Whether historical aerial photograph analysis, explosive ordnance surveying, surface surveying using GPR, magnetometry or TDEM, deep-ground surveys, downhole surveys, excavation supervision, area clearance or ordnance recovery is needed depends on the location, ground disturbance, depth, ground and existing documents. An early ordnance assessment provides clarity for tendering, programming, occupational safety and construction.

FONTANA-EOD combines its Section 7 SprengG licence, specialists holding Section 20 SprengG certificates of competence, suitable survey and clearance methods, and traceable documentation. Send the site plan, depth of ground disturbance, construction phase and existing documents for an initial technical assessment.

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