Technical map view of the Münster administrative district with Münster marked for explosive ordnance investigation and surveys by FONTANA-EOD

Prepare explosive ordnance surveying in Bottrop

Who provides access for the survey, which documents are missing and what remains to be done afterwards? According to the city’s information, preparatory, accompanying and follow-up works in Bottrop are the responsibility of the property owner or client. FONTANA-EOD supports the commissioned technical preparation and documentation.

Commission and responsibility

Clarify who initiates the investigation and supporting works.

Access and construction area

Record obstacles, installations and missing information.

Reports for site management

Record investigated areas and outstanding tasks.

Discuss survey preparationExplosive ordnance assessment in North Rhine-Westphalia
Assess the construction project

Assign investigation and supporting works individually

For construction projects involving ground interventions, the City of Bottrop describes an application for explosive ordnance assessment to the local regulatory authority. If aerial photograph analysis provides relevant indications, the city initiates a survey. The municipal allocation of tasks distinguishes this investigation from ground preparation, accompanying and follow-up works on the property owner’s or client’s side.

Before the appointment, therefore clarify who makes the area accessible, which preparatory works are complete and which supplementary specialist works are to be commissioned. A survey appointment does not automatically cover every task in the construction area. Establish the documents, responsibilities and outstanding conditions before the affected ground interventions begin.

One specific local example is the downhole magnetometry at the A 2, Kirchhellener Straße. The downhole and deep-ground survey explains the method. For a project enquiry for your own construction area, we need a site plan, intervention depths and existing assessments; the reference commission is not extended to other areas.

Project references

Selected project examples

Project site

Connect the site with the specific construction task

Schematic map with a coat of arms, alongside a tablet, safety helmet and notebook.

Consider Bottrop’s task allocation in planning

The city identifies the local regulatory authority for the application and the explosive ordnance disposal service at the Arnsberg district government for aerial photograph analysis. Where relevant indications exist, it initiates a survey. Municipal information assigns preparatory, accompanying and follow-up works to the property owner or client. The specific private service scope is agreed separately and explicitly. Bottrop is an independent city in North Rhine-Westphalia and belongs to the Münster administrative district. For projects in the city centre, Kirchhellen or other parts of the city, state the precise project address and application area. For multiple construction sections, identify the respective interventions and next decisions separately. The actual project location determines the municipal contact.

North Rhine-Westphalia
Local context

Municipal procedure and tasks at the construction area in Bottrop

Bottrop application and state survey

The City of Bottrop describes applying to the local regulatory authority as the starting point for construction projects involving ground interventions. Where aerial photograph analysis gives relevant indications, it initiates a survey; it identifies the explosive ordnance disposal service at the Arnsberg district government, Hagen branch, for aerial photograph analysis. These responsibilities must be distinguished from separately agreed specialist company services. The Fachbereich Recht und Ordnung is the municipal receiving department.

In its communication of 17 February 2026 it notes that assessment is required even for excavation of only a few centimetres. The city advises applying early and specifies a site plan to be emailed to gefahrenabwehr@bottrop.de. Municipal requirements are therefore considered already when planning preparatory groundworks.

The municipal study of the Hansaviertel describes the destruction of industrial facilities and city-centre buildings by air raids during the Second World War and subsequent reconstruction. For present-day projects, historical construction and use records are compared with the specific intervention. Former mining and operational sites, railway and utility corridors, and later alteration and development areas are considered according to their documented history of use.

Tasks for the property owner and client

Clarify early which preparatory, accompanying and follow-up works your project needs. The city assigns these to the property owner or client. An agreed survey appointment does not establish whether the area is ready or who undertakes the subsequent works. Bottrop’s published fee information relates to the survey described there and any necessary disarming or regulatory measures. The commission, scope and remuneration for private specialist services are agreed separately. Therefore identify the activities you need in addition to the municipally initiated investigation and the contractor intended for them. For commissioning, record who provides access, which preliminary works are already complete and which services the specialist company should undertake. Facilities supplied by the construction participants and works still to be commissioned are identified separately. Quotations are compared using the same area, depth and task status.

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?

Record the actual preparation status

Compare the requirements of the intended investigation with the existing conditions. Access, documents and technical measurement conditions are different questions. Saying the area is clear does not answer them fully. Identify the available basis and clarification still needed for the specific investigation commission.

Assess historical documents

Keep the outstanding task identifiable in restricted areas

If an area cannot be adequately investigated, this must remain identifiable in further planning. The appropriate approach is agreed on technical grounds and with the responsible authorities. Mere visual observation does not replace missing detection. Private supplementary services are agreed only within the respective NRW requirements.

Compare investigation methods
Project types

Connect each preparation step with a clear task

Illustration: two people review plans and documents at a table beside a construction vehicle.

Identify necessary preparatory works specifically

A general description such as preparing the construction area does not show the activities actually proposed. Describe access, known obstacles and documents needed individually. Necessary ground interventions are clarified technically beforehand. The purpose of enabling a later investigation does not automatically make the preparatory activity safe.

Coordinate the sequence and tasks
Illustration: two people review plans and documents at a table beside a construction vehicle.

Assign outstanding information to a contact person

Record who is dealing with a missing plan or unresolved access condition. The response and its basis are incorporated into the project documents. An organisational commitment must be distinguished from confirmed technical findings. Unchecked information remains identifiable until the necessary clarification has taken place.

Document findings and their limitations
Illustration: two people with a tablet beside a drawing table and a survey trolley on a construction site.

Describe follow-up works as well

Reinstatement or a subsequent construction change may involve ground interventions of its own. Record their area and depth. The name of the works does not determine whether the existing result covers them. Additional areas are compared with the documented investigation scope before execution.

Specialist services and investigation tasks
Preparation

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 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 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 schedule
Tasks at the site

Hand over documents, the construction area and results in good time

01

Site plan and previous results

Compile the current site plan, a description of the groundworks and existing results. Identify additions and contradictions. Mark information still needing verification so that it does not enter the commission as a confirmed basis. Each report includes its corresponding plans, the investigated area, the construction task intended at that time and identifiable limitations. Place the application area and current design alongside these. If the construction section has changed, also identify the new working volumes and depths affected. Technical preparation clarifies which findings can already be related to the planned works and which documents remain missing.

02

Access and condition of the area

Agree the condition the area must be in for investigation. Clarify access and known installations or obstacles. Preparatory ground interventions also need the necessary technical clarification beforehand. Time pressure does not justify bringing them forward unchecked. Describe the actual surface, access routes and areas accessible for investigation. Identify installations, stored materials or ongoing operations with their locations and available working windows. The specialist company agrees the necessary prerequisites for the intended method with the participants. The condition at the investigation appointment and changes planned later remain distinguishably documented. The respective employers include the proposed activities and their interfaces in the risk assessment. Changes in accessibility are communicated before the relevant investigation appointment.

03

Changes to the area and sequence

Inform participants if a working area moves or a subarea is inaccessible. State which area and work step are affected. The previous plan may need adjustment.

04

Report with investigated areas

Site management needs the report with the investigated areas and identified limitations. Notification that an investigation took place is insufficient. Mark outstanding areas for further construction planning.

Project documents

Documents that establish the next step

Separate officially initiated and private tasks

The city describes the route from application to the necessary survey. Supplementary services are distinguished by their respective commissions and applicable requirements. Record which authority initiates which step. A private agreement on preparatory works transfers neither state tasks nor decision-making concerning an investigation result. The quotation and work plan identify individual tasks with a responsible participant. Record who obtains documents, clarifies access and organises necessary preliminary services. An outstanding prerequisite receives a date and contact person. Changes to areas or construction sequence are communicated to the affected companies and municipal authority where their tasks are concerned.

Coordinate changes to the construction area in good time

If an area is not available as intended, participants need an up-to-date description. Identify the affected area and effects on the task. The original schedule or work plan is not continued unchecked. Subareas actually not investigated remain visible in the subsequent report.

For handover after investigation, record which condition was investigated and which works remain planned afterwards. These may include further utility excavations, reinstatement of affected areas or changes to a construction section. Relate such activities to their actual positions and intervention depths. If they extend beyond the documented investigation scope, the additional requirement is clarified technically before execution.

Provide site management with the report, its plan appendices and a list of outstanding tasks. Following clearance work, the clearance record with the subareas treated, actual clearance scope and results is included in this handover status. The companies involved receive the documents needed for their working areas. Later commissioning of follow-up works is prepared using this state of knowledge.

Construction sequence

Coordinate investigation and construction sections

Before establishing the task allocation

List the intended investigation and necessary preparatory, accompanying and follow-up works. Assign a responsible participant and required underlying information to each activity. Outstanding questions remain explicitly identified. A comprehensive-sounding commission title does not replace a traceable description of the actual service scope.

Coordinate the construction phase with us

Before the next construction phase

Check which works are complete and which investigation results are available in full. Relate the report to the next interventions. Providing access is not evidence concerning explosive ordnance; a technical report does not automatically answer reinstatement questions. The respective information needed is passed on separately.

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 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 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 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 limitations

Deep-ground and downhole surveys

For deeper interventions, it may be necessary to check whether investigation from the surface provides the findings needed or whether another approach is required. Position, depth, borehole arrangement and existing utilities then belong in preparation. Provision of investigation access must also be planned in a technically suitable way. A general depth figure or standard grid does not replace this task. Results remain tied to the areas actually addressed and the method used. For proposed geotechnical boreholes, submit the borehole points and starting elevations with the intervention depth. Identify which explosive ordnance findings are needed before forming the borehole starting point. Geotechnical investigation and evidence for an intervention concerning explosive ordnance have different tasks. The agreed findings are documented with reference to the borehole point, area and technical limitations. If borehole points move or additional ones are added, compare the findings with the plans again before the affected works.

Prepare deep interventions

Survey 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 construction
Technical assessment

What must be clarified before investigation

Aerial photograph analysis and investigation

The historical aerial photograph analysis provides findings different from the on-site technical investigation. A historical indication may justify further investigations. The suitable areas and methods require technical assessment and agreement with the responsible authority.

Installations and possible interference

For a survey, utilities, metal installations and other site conditions may be relevant. Match preparation to the proposed method. Saying the area is clear does not replace an assessment of measurement conditions.

If a subarea cannot be investigated

If the intended investigation is not possible in a subarea, the subsequent approach must be technically agreed. The clearance plan or investigation plan must describe the outstanding task. Mere visual observation of excavation does not replace a missing technical investigation.

Next steps

Establish who undertakes each task before the appointment

01

List investigation and supporting works

List which investigation is officially initiated and which supplementary works you must organise. Describe the individual activities. A general term such as complete preparation does not show who clarifies access, obstacles or missing documents. For the initial project enquiry, discuss the construction task, areas, depths and next decision needed. Demolition, connections and temporary construction conditions are included alongside new buildings. Known utilities and the respective current plan version are identified.

02

Assign outstanding points to a contact person

List missing documents and unresolved conditions on the area. Identify a project contact for each point. Official responsibilities remain unaffected. Check official information, aerial photograph analyses and investigation reports for plan version, spatial coverage, depth reference and outstanding questions concerning today’s task. The scope actually documented is decisive. Missing or conflicting information is identified with its relationship to the planned intervention.

03

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.

04

Update changes in the work plan

Enter changes such as restricted access or a moved intervention area in the work plan. Match the further investigation to that situation. A sequence that no longer fits must be adjusted. The specialist company selects the technically suitable approach using the investigation objective, grounds for suspicion, ground composition, interference and accessibility. Preliminary services and the permissible activity scope are clarified. Investigation areas and interfaces are coordinated with the construction sequence.

05

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.

06

Compare the next groundworks with the report

Before subsequent works, check whether the report covers the planned areas and depths. Additions and deeper interventions require separate clarification. This also applies to follow-up works: their name does not extend the investigated area. Work performed and its technical assessment are documented in a report with the corresponding site and plan appendices. Methods, areas addressed, depth references and limitations of findings remain traceable. The client and designers compare this status with the next construction phase. Additional specialist works or official steps are identified before the interventions they concern.

Documentation

Evidence needed by site management

Findings and their scope

At handover, record separately which investigation results exist and which supporting works are complete. Providing access is not evidence concerning explosive ordnance. An investigation report, in turn, does not clarify every question of reinstatement or the next construction phase. Retain the corresponding plans and reports in the project file.

Project responsibilities

FONTANA-EOD’s services are subject to the legal limitations of the respective commission. Section 3 of the KampfmittelVO NRW governs the handling of explosive ordnance and limited exceptions for certain private activities. A private commission alone does not fulfil these conditions. The BFR Kampfmittelräumung provide technical guidance outside their federal scope of application.

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

Completed preparation is not yet a result

Access, supplied plans or agreed appointments may fulfil important prerequisites. They do not document an explosive ordnance investigation performed. Therefore record these work statuses separately. Site management can then identify whether a prerequisite has been provided or the technical findings needed actually exist.

Understand investigation reports and their limitations

A task list needs verifiable information

Describe activities and outstanding questions so that their completion is traceable. Identify the corresponding plans, contacts and affected areas. General collective terms may conceal gaps. The list supports organisation and replaces neither technical investigation nor the complete results report.

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
Person in an orange high-visibility vest with a MALÅ survey cart on a meadow.
Person in a high-visibility vest in front of a marked construction area with piles of soil.
Questions from planning

Questions about preparing a survey in Bottrop

Who initiates further investigation in Bottrop?

The application is submitted to the regulatory authority. If aerial photograph analysis provides relevant indications, the City of Bottrop initiates a survey. Clarify separately which supplementary tasks you must and may commission privately.

Are preparatory works automatically part of the survey?

The City of Bottrop assigns preparatory, accompanying and follow-up works to the property owner or client. Therefore clarify which activities your project needs and who carries them out properly.

May an obstructing structure simply be removed beforehand?

If removal requires a ground intervention or other changes relevant to investigation, it must be technically coordinated beforehand. The explosive ordnance question must also be clarified for such preparatory interventions.

What happens to a subarea that was not investigated?

Mark the subarea in the report as not investigated. Whether and how investigation can be supplemented requires technical clarification and agreement with the responsible authorities. Results from neighbouring areas do not automatically apply to the omitted area.

What should be done if a suspicious object is found during preparation?

Stop the affected works and do not touch or move the object. Move away, keep others away and notify the police immediately on 110 or the local regulatory authority. Follow their instructions; do not attempt recovery yourself.

Why are preparatory and follow-up works listed separately?

So that their actual scope and responsibility are identifiable. Additional ground interventions during preparation or reinstatement must also be compared with the existing information.

What belongs in notification of a changed construction area condition?

The affected area, specific change and its significance for the intended task. The current plan version is passed to the participants.

Which costs and dates must be clarified before commissioning?

According to Bottrop’s information, no fees are charged for the survey described there and any necessary disarming or regulatory measures. Preparatory, accompanying and follow-up works are borne by the property owner or client. Private specialist services are agreed separately. Costing considers areas, depths, methods, access, preliminary services, assessment and documentation. Coordinate complete documents, necessary prerequisites and the actual procedural status with the proposed construction dates.

Project enquiry

Prepare a survey in Bottrop

Describe tasks individually

Identify the investigation, preparatory works needed and planned follow-up interventions with their contacts. For the first discussion, list completed preparations, actually documented investigation results and outstanding follow-up tasks separately. Describe which works are officially initiated and which additional activities you wish to commission. State the area affected, findings needed and intended timing for each service. If a task is not yet defined, identify the outstanding question. Technical coordination can build on this and assign the next necessary steps.

Substantiate the previous status

Send official information, current area plans and existing reports with outstanding requirements. The reports include their corresponding plan appendices and investigation objectives at that time. Mark the next construction phase and new or deeper interventions. Missing documents and inaccessible subareas are explicitly identified. If construction area conditions change, record the affected area, specific change and significance for the intended work; pass on the new plan version. After an interruption, earlier results remain tied to their documented scope. Before resuming, clarify whether the existing information covers the works now planned. Mark schematic illustrations and unconfirmed depths.

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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