Project pathway
The quickest route to the right decision.
Ordnance investigation in Bergisch Gladbach when groundworks change
Are you changing the foundations or retaining works but already have an aerial imagery analysis for your property? Before groundworks, check whether its findings cover the new construction method. FONTANA-EOD supports clients, specialist planning and site management in Bergisch Gladbach with the specialist assessment and planning commissioned. The changes are compared with existing reports, maps and limitations.
Read the findings, area analysed and limitations.
Show the location, depth and construction method on the new plan.
Clarify outstanding questions before construction.
Assess the construction project
Changed foundations need a fresh comparison
Even where the area and depth remain the same, a different construction method can change the specialist task. For your project in Bergisch Gladbach, we compare the new design with the purpose and limitations of existing ordnance documents. Further work depends on the actual groundworks and official requirements.
Project site
Connect the site with the specific construction task
Use local information and the older planning example separately
Bergisch Gladbach is in North Rhine-Westphalia, in the Rheinisch-Bergisch district and the Cologne administrative district. The town's general public order authority is responsible for the municipal application; the state explosive ordnance disposal service for the Rhineland is based at the Düsseldorf District Government. The published letter concerning development plan 6130 of 15 January 2020 draws on an older analysis. For a new or changed construction task, current plan attachments and the associated investigation status are agreed with the competent authority. The project address and actual groundworks areas determine which documents need to be brought together.
Local context
Compare older analyses with the present-day construction site
Local procedure and existing analyses
In Bergisch Gladbach, the application for aerial imagery analysis is addressed to the general public order authority. Details of the client and property, together with a map extract, are required. The district government analyses the aerial imagery. For further planning, check whether the analysis covers the area and groundworks in your current design. The town's service page specifies an application for construction work deeper than 80 centimetres. It requires details of the client, the property owner and the plot address, including cadastral district and plot number, together with an extract from the Deutsche Grundkarte at a scale of 1:500. The result is returned through the public order authority. Other ground interventions, specific indications of suspected ordnance and changes in construction method are also clarified with the competent authority before being carried out. For specialist planning, the town's application guidance is considered together with the specific construction task and existing findings.
The Bergisch Gladbach town archive records an Allied air raid on the town on 3 February 1945. Historical investigation compares these indications, placed in their time context, with available wartime aerial imagery, former property and street names, and later ground changes. The investigation needed for your construction project follows from the spatially assigned findings and planned groundworks.
Construction method as part of the specialist question
The town's letter of 15 January 2020 concerning development plan no. 6130 refers to an earlier aerial imagery analysis. It identifies no indications in the area analysed, but also records parts that could not be interpreted and gives no guarantee that the area is free from ordnance. Safety detection is recommended for earthworks involving substantial mechanical loads. These statements apply to the identified project, not to other properties in Bergisch Gladbach. The attached analysis of 4 January 2011 and its map form part of this documented context. The plan distinguishes the previous and then-current application areas and areas that could not be interpreted. For the present-day project record, the covering letter, attachments and maps are therefore filed together with the plan revision used at that time.
The town also reports in its announcement of 9 December 2025 on Nittumer Weg: after an aerial imagery analysis with no initial indications of suspected ordnance, ordnance was found during civil engineering work. The public order authority and explosive ordnance clearance service were involved, and extended detection was ordered. For further planning, the evidence available, area investigated and actual groundworks proposed are decisive when considered together.
Requirements
Clarify technical requirements and responsibilities within the project
Relate requirements to the specialist task
For the commissioned activities, the relevant technical requirements and questions of permits, competence certification and responsibility are clarified. The actual planned service scope is decisive. A general company designation does not replace checking that the tasks and interfaces are described appropriately for the specific project.
Link occupational safety to the construction sequence
Risk assessment, work areas and communication must suit the proposed activities. Ordnance specialist works are coordinated with the other construction activities. Operational organisation, traffic safety and other specialist technical inspections retain their own responsible parties. Joint coordination brings the information together without equating the different tasks.
Use technical findings correctly
A measurement anomaly first requires specialist assessment; its appearance alone does not identify it as explosive ordnance. If an object is genuinely suspected to be ordnance, the prescribed reporting procedures and the measures set by the responsible authorities apply. Investigation reports specify the work completed and its limitations, so that results are not extended to unexamined areas or later design changes.
Procedure at the site: Town of Bergisch Gladbach: explosive ordnance · Town of Bergisch Gladbach: aerial imagery analysis for development plan 6130, letter of 15 January 2020 · North Rhine-Westphalia KampfmittelVO: Section 3 in particular.
Planning and documentation: BFR KMR: principles of clearance planning · BFR KMR: geophysics · BFR KMR: documentation · North Rhine-Westphalia Ministry of the Interior: explosive legacy
The BFR KMR are used as technical guidance; locally applicable requirements and responsibilities must be clarified separately.
The permit, qualifications and responsibilities for the specific activity are assessed under the Explosives Act and the First Ordinance to the Explosives Act. The risk assessment under Section 5 of the Occupational Safety and Health Act relates to the planned activities. The DGUV Information 201-027 addresses preventive investigation and clearance of conventional explosive ordnance and defines its scope. The references it explains to DGUV Regel 113-003 concern specific activities involving explosives; they are not applied indiscriminately to every construction investigation.
For private activities in North Rhine-Westphalia, the requirements of the exceptions under the KampfmittelVO and the official guidance are related to the construction task. The narrowly defined exceptions concern downhole detection in specialist foundation engineering and explosive ordnance clearance during construction under the respective applicable conditions. Before an agreement, the site conditions required by the state, authorisations and coordination are clarified. Specific indications of ordnance contamination are handled through the responsible state procedure. Any notifications required under explosives legislation must also be observed.
Working together
Distinguish the tasks of client, designers and specialist contractor
Client and operator
The project owner describes the proposed work and provides the available project documents. The operator adds requirements for use, access and timing. A coordinating contact makes cooperation easier but does not automatically take on every other party's duties. Before commissioning, record clearly which information is missing, who will obtain it and which decision the result is intended to support.
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 carries out the agreed investigation and documentation scope. Official requirements and decisions are clarified with the competent authorities concerned. The documents needed for a particular procedure depend on the location and project. The technical report describes the specialist service performed; its conclusions are not presented unchecked as general authorisation for further groundworks or as an authority's decision.
Investigation task
Which specialist task comes next?
Establish the original investigation purpose
Check which groundworks an existing result was prepared for. Area covered, depth, method and limitations belong together. An aerial imagery analysis with no indications does not automatically provide findings for every later construction method. The specific content of the document is decisive, rather than its general title alone.
Assess historical documentsHave the change assessed by specialists
The comparison identifies which additional question needs clarification. A change to the plans does not automatically require the same measure in every project. Further work is determined by site conditions and official requirements. For private activities, the applicable North Rhine-Westphalia conditions are checked before an agreement.
Compare investigation methodsProject types
Describe changes to the plans in full
Show the change in a structure's location
Show the old and new positions using the same spatial reference. Even a small shift can affect an area not previously covered. The specialist comparison follows the actual boundaries of existing results. An unchanged property number does not replace assessment of whether the new work area lies within those boundaries. Identify investigated areas and newly affected areas using the same coordinate or spatial reference. This also includes working areas beside the structure itself, utility connections and areas for preparatory measures. Where several construction phases are involved, each change receives a traceable link to the associated report and proposed work.
Document findings and their limitations
Identify the new construction method
If the foundation type or the construction of a support element changes, this is explicitly communicated. The same final depth does not necessarily mean the same loading of the ground. Describe the proposed groundworks so that the specialists involved can assess them. Selecting a new method does not automatically extend existing ordnance findings. The assessment describes the activities actually planned, for example driving work, piled foundations or additional retaining works. Identify the structures and work areas affected. Specialist planning relates the change to existing results and clarifies which additional investigation question it raises. On this basis, selection of a technical method is coordinated with the official steps required.
Specialist services and investigation tasksInclude preparatory work in the design
Additional exploratory openings, retaining elements or other preparatory groundworks form part of the updated plans. Their location and purpose are identified. Taking place before the main construction work does not make them an activity already assessed. Their prerequisites are likewise checked against existing documents before they are carried out.
Coordinate the sequence and tasksPreparation
Prepare the scope and commission together
The following specialist topics explain possible investigation tasks. Which activity may be privately commissioned under the specific North Rhine-Westphalia procedure is clarified separately before an agreement.
Establish what needs to be known before commissioning the work
First establish which decision the commission needs to support. Is the task an initial assessment of existing documents, an investigation of a specific area or examination of an anomaly that has already been assessed? These tasks require different evidence. A general wish for safety does not define an investigation that can be carried out. The enquiry therefore specifies the groundworks, location, depth and available findings. Suitable specialist work and the required reporting are then agreed on that basis.
Define the specialist taskCoordinate 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 programmeAgree a clear scope and schedule
A sound workflow distinguishes work already clarified technically from outstanding prerequisites. If an area will be accessible only in part, commissioning must take this into account. Handover and assessment of results also need time in the construction sequence. An enquiry therefore does not imply a blanket commitment on dates or cost. Specific coordination connects the described scope with access, documents, execution conditions and the date by which a decision is needed.
Discuss the scope and scheduleTasks at the site
Which changes should be clarified before groundworks
01
An enlarged or relocated construction area
Show on the plan where the new design extends beyond the area previously covered by the enquiry. This might be an additional corner of an excavation or a new utility route. The same project name does not establish whether these areas are also covered.
02
Changed foundations
State the foundation type, location and extent of the proposed structures. A change in construction method may require a new specialist assessment even if the building footprint remains unchanged. Check whether the earlier analysis is sufficient for the new work.
03
Additional retaining works
Describe additional retaining measures with the location and type of work proposed. Ground elevation alone provides too little information for this. Agree what further assessment is required on the basis of the proposed method.
04
Preparatory work
Include groundworks for investigation, site establishment and access routes in the list of changes. They need the necessary specialist clarification before being carried out, even if they serve only as preparation.
Project documents
Documents that establish the next step
Link old and new plans clearly
Identify revisions by date and the change concerned. The original documents are retained as the basis of the earlier result. A comparison helps assess the actual difference. Unchanged and newly added areas are shown so that those involved can distinguish them clearly.
For an older report, the map designations and attachments used at that time are fully assigned. Transfer identifiable gaps or uninterpretable parts of the site from the document into the current spatial reference and identify the origin of this information. Missing attachments are recorded as outstanding evidence. Specialist assessment can then distinguish areas actually investigated, areas considered historically and areas still unresolved. The term uninterpretable is assigned to the aerial imagery findings at that time. For technical investigation planning, it is clarified separately which findings are available today for this area and which question still needs an answer before the proposed groundworks.
File a supplementary assessment with the reason for it
Document which change to the plans the further specialist work concerns. Site management receives the result together with the relevant new plans. An additional report is not used in isolation from the earlier limitations. The project record should show which findings belong to which revision of the project. After clearance work has been carried out, the clearance record, including the sections treated, actual clearance scope and results, is filed in the project record together with the relevant site plan. The handover also identifies which additional specialist work is outstanding and which construction phases it affects. Site management receives the plan attachments needed for construction with their respective limitations. If structures are subsequently relocated again or another method is selected, the change is reported back before the relevant work. Further work thus remains tied to the task actually documented.
Construction sequence
Coordinate investigation and construction sections
Before deciding on a changed construction method
Show the planned difference with its location, depth and construction method. Include the complete ordnance documents and the associated earlier plans. Specialist coordination should take place before the changed activity is carried out. This leaves time to assess outstanding questions and possible additions specifically.
Before handover to the contractor
Hand over the current plans and the results relating to them together. Identify changes not yet assessed and remaining limitations. Superseded revisions remain identifiable as such. A plan used in construction should not suggest that an activity added later was already covered in the earlier report.
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 assessmentMagnetometric 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 magnetometryElectromagnetic methods
Electromagnetic investigations can be suitable for particular metallic targets and site conditions. Their suitability must be explained for the task, rather than inferred simply from the availability of equipment. Interfering installations, accessible areas and the findings required must also be considered. Results are documented with their location and survey conditions. The specialist assessment determines whether a supplementary method is needed; this remains a project-specific decision.
Understand electromagnetic surveyingGround-penetrating radar
Under suitable conditions, ground-penetrating radar can provide information about subsurface structures and reflections. Ground conditions, moisture, installations and the particular survey task affect interpretability. An anomaly is not automatically ordnance, and an area with no apparent anomalies is not general evidence for arbitrary depths. The specialist interpretation and its limits are documented with the instruction. A survey for another purpose is not adopted without checking as ordnance evidence.
GPR and limitationsDeep-ground and downhole surveys
For deeper groundworks, it may be necessary to check whether investigation from the surface can provide the information required or whether another approach is needed. Location, depth, borehole layout and existing utilities then form part of preparation. The provision of investigation access must also be planned appropriately on specialist grounds. A general depth figure or standard grid does not replace this task. Results remain tied to the areas actually investigated and the method used. For additional or relocated borehole positions, provide the location, starting elevation and proposed depth of groundworks with the current plan revision. Identify the ordnance information required before the groundworks. The purpose of a ground investigation is distinguished from the investigation objective of ordnance assessment.
Prepare deep interventionsSurvey during construction
If a necessary preliminary investigation cannot be completed, the specialists assess whether a planned approach during construction is suitable. This includes coordinated investigation, interpretation and communication of findings within the intended work sequence. Visual observation of excavated material is not an interchangeable substitute for a necessary survey. Site management needs a clear description of when specialist work will take place, how new findings will be handled and which areas remain unresolved.
Agree the approach during constructionTechnical assessment
Analysis, investigation needs and the new plan revision
Scope of the aerial imagery analysis
A historical aerial photograph analysis relates to specific documents and the area covered by the enquiry. It does not replace a technical investigation. Read the notes and limitations before using the result for a changed construction design.
Need for an investigation on site
Whether a survey or another method is required depends on the outstanding questions and site conditions. A depth figure alone is insufficient for this decision. Construction method, existing findings and the specific groundworks area must be considered.
Revised investigation plan
A clearance plan or investigation planning must identify the changes taken into account. Identify the new revision and the plan revision superseded. Record which previous results can still be used and why further steps are needed.
Next steps
Submit the changed plans for assessment
Bring together previous documents
Bring together the decision or report with maps and appendices. Check which application and area it relates to. A single sentence stating a result may omit limitations important for your new plans. The initial project enquiry discusses the construction task, areas, depths and next decision required. In addition to new buildings, demolition, connections and temporary construction stages are included. Known utilities and the respective current plan revision are assigned.
Compare the changes
Compare the old and new locations, depths and construction methods. Add newly planned preparatory work. Specialist planning must be able to identify what has changed; simply referring to an updated design is insufficient. Responses, aerial imagery analyses and investigation reports are checked for plan revision, spatial coverage, depth reference and outstanding questions concerning the current task. The scope actually documented is decisive. Missing or contradictory information is identified in relation to the planned groundworks.
Supplement historical information
The required state aerial imagery analysis is initiated through the municipal procedure provided locally. If the available findings need supplementation, further historical research is carried out for the specific question. Available aerial imagery, maps and records of use are professionally analysed and related to the present-day construction site. The findings feed into further investigation planning.
Involve the competent authorities
Agree which additions are required for the changed groundworks. Involve the local public order authority according to its responsibilities. A discussion within the planning team does not replace an official decision required. The specialist contractor selects the technically suitable approach according to the investigation objective, basis for suspected ordnance, ground composition, interference and accessibility. Preparatory services and the permissible scope of activity are clarified. Investigation areas and interfaces are coordinated with the construction sequence.
Investigate and assess results
Within the agreed and permissible scope, the defined areas or points are investigated using a suitable method. The data collected are recorded with location, depth reference and site conditions. Specialist personnel assess results and anomalies according to the investigation objective, method and interference. A measurement anomaly is not yet identified ordnance. Further clarification required and areas not adequately investigated are identified; local reporting procedures apply if ordnance is found.
Hand over current documents to site management
Hand over current reports and plans with their limitations. Identify results that can still be used and questions newly clarified. Site management joining later must also be able to identify which documents apply to construction. The work carried out and its specialist assessment are documented in a report with associated site and plan attachments. Methods, areas investigated, depth references and limitations remain traceable. The client and planning team compare this status with the next construction phase. Additional specialist work or official steps are identified before the groundworks they affect.
Documentation
Compare the area analysed with the present-day construction task
Findings and their scope
If an aerial imagery analysis contains no indications of ordnance, that finding applies to its evidence base and the area analysed. It is not a guarantee for all future earthworks. The letter concerning development plan 6130 explicitly identifies this limitation. Its result must not be transferred to another property.
Project responsibilities
The BFR Kampfmittelräumung provide specialist guidance for revising investigation planning. Their direct scope and the responsibilities in North Rhine-Westphalia are taken into account. FONTANA-EOD carries out the legally permissible specialist tasks commissioned. Specialist findings, official requirements and the project's decision on the next construction phase are each assigned to the responsible party.
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 taskThe 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
The same depth describes only part of the groundworks
Two construction methods can reach the same depth while loading the ground differently. The planned activity is therefore also identified for the specialist comparison. Comparing depth figures alone is not sufficient in every case. Existing findings are assessed according to their own task and the new construction plans.
Understand investigation reports and their limitationsRead an older analysis with its attachments
In the published Bergisch Gladbach case, the letter from 2020 is accompanied by an older analysis from 2011 and its map. The report, time context and boundaries shown must be considered together. A statement removed from its context can conceal significant limitations. It does not provide an assessment transferable to other properties. The town archive documents an air raid on Bergisch Gladbach on 3 February 1945. Historical documents are assigned to the respective area and the question addressed by the present-day project. The place names used at that time and subsequent development of the construction site are therefore important for analysis. Specialist assessment is based on the local, construction and investigation documents actually available for the affected site.
Understand the service scopeDesign and findings
Documents for the next construction decision
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 assessmentSpecialist 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
Further technical topics
Further technical information for your project
Determine the specialist service from the planned groundworks
Historical assessment, technical investigation and further work answer different questions. For the enquiry, the investigation objective, existing results and outstanding decisions are assigned to the appropriate specialist task.
Compare servicesCoordinate the project sequence with everyone involved
Preparation connects the commission, site work and handover of findings. Changes to the project can then be incorporated into technical coordination in good time.
Process and documentationQuestions from planning
Questions about earlier analyses and changed construction methods
Can an earlier aerial imagery analysis still be used?
Yes, it may still contain important findings. Whether it is sufficient for the current plans must be checked against the area investigated, its limitations and the new groundworks. The complete analysis and current construction plan are needed for this.
Is an area with no indications guaranteed to be free from ordnance?
No. The finding applies to the documents analysed and the area described. The letter concerning development plan no. 6130 explicitly distinguishes the absence of indications from a guarantee. It also provides no findings about other properties.
What needs reassessment besides greater depth?
A relocated construction area, different foundation type or changed mechanical loading may also require a new assessment. Describe the planned work in full. An unchanged depth alone does not establish that the changed construction method is safe.
Does every construction change require a new investigation?
This cannot be answered as a blanket rule. Existing findings, the specific change and applicable requirements are assessed. Only then do the further steps required become clear. Private work must remain within the North Rhine-Westphalia regulations.
What should be done if a suspicious object is found?
Stop the affected work, do not touch or move the object, and keep your distance. Warn other people from a safe distance. Notify the police, fire service or public order office immediately and follow their instructions; do not examine or recover the object yourself.
Which details are needed for changed foundations?
The old and new locations, depths, elevation references and proposed construction method, together with the associated plan revisions. This allows the difference to be compared with existing results.
Why should older attachments be sent in full?
Because they may contain the spatial boundaries and limitations of an analysis. A covering letter or short statement of results alone may not fully represent this context.
When should coordination take place, and what determines effort and costs?
The changed construction method is coordinated before it is carried out and, where possible, before the programme is finalised. Those responsible need a specific description of the change and the existing documents. Effort and costs depend on the affected areas and depths, investigation objective, existing documents, preparatory services required, accessibility, method, interpretation and documentation. In the enquiry, identify the next construction phase and the specialist decision needed for it.
Project enquiry
Coordinate changed groundworks early
Identify the change to the plans
Compare the old and new locations, depths and construction methods, with dates. Assign each change to the affected structure, its purpose and the associated report. Additional excavation support or a newly planned connection is also described with its proposed construction method. Services already commissioned and specialist tasks still outstanding are identified separately. Initial coordination can then specify the findings actually required and the involvement of the competent authorities.
Provide the analysis with its attachments
Send complete reports, maps and official letters with their respective relationship to the project. Older results need their complete maps, attachments and original tasks. Identify parts that could not be interpreted and differences between the old application and the new groundworks area. State which preparatory work has already taken place and which remains. After an interruption or change of contractor, valid plan revisions, outstanding questions and further tasks required are passed on together. New site management can compare this information with the proposed work area.
Investigation methods and their limitations
Investigation methods and their limitationsWorking together within the project
Working together within the projectUnderstand regional responsibilities
Understand regional responsibilitiesClarify further investigation of findings
Clarify further investigation of findingsDefine the construction task and application
Define the construction task and applicationCoordinate area-based work on specialist grounds
Coordinate area-based work on specialist grounds
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.
