Technical map of the administrative district of Detmold, marking Detmold as a location for ordnance investigation and surveying by FONTANA-EOD

Explosive ordnance surveying in Gütersloh: identify subareas

Different parts of a construction area may have different explosive ordnance findings. FONTANA-EOD supports the commissioned assessment in Gütersloh of which information applies to the planned groundworks. Maps, reports and construction plans are compared: where has investigation already taken place, which limitations exist and which questions remain open?

Findings map and report

Relate findings to the correct area.

Differences within the construction area

Record differing results in the work plan.

Planned groundworks

Compare position and depth with the documents.

Discuss findings for the construction projectExplosive ordnance assessment in North Rhine-Westphalia
Assess the construction project

Different subareas need precise identification

A planning area may contain several areas with different findings and requirements. For your project in Gütersloh, we compare maps, report text and the positions of planned interventions. A colour’s meaning follows from its corresponding legend and findings; additional technical questions are considered with their own documents.

Project references

Selected project examples

Project site

Connect the site with the specific construction task

Schematic map with the North Rhine-Westphalia coat of arms, beside a tablet, safety helmet and notebook.

Limit the Gütersloh planning example to its area

The explanation for the 13th amendment to the land-use plan from August 2024 describes differing explosive ordnance findings and names the Arnsberg explosive ordnance disposal service and Fachbereich Ordnung. It concerns a specific planning area. For your project, affected areas are compared with the corresponding current documents and planned groundworks. Gütersloh is a town in the district of the same name, Detmold administrative district, in North Rhine-Westphalia. State the precise project address and affected areas. For a project in another municipality in the district, the respective local responsibility is clarified separately. Spatial identification connects the location with the relevant documents and responsible authorities.

North Rhine-Westphalia
Local context

Differing information within a Gütersloh planning area

Different areas in the Gütersloh planning example

The explanation for the 13th amendment to Gütersloh’s land-use plan from August 2024 addresses explosive ordnance in section 2.5. It distinguishes several marked areas within the amendment area. Surveys are mentioned for one area; for another, the explanation contains a different assessment and guidance on responding to finds. This information belongs to that particular planning procedure.

Compare findings with the actual intervention area

Your project needs documents covering the area actually affected and current plans. The 2024 planning explanation does not provide general information about properties in Gütersloh. Therefore do not extend an assessment of one subarea unchecked to the entire construction area.

An image in the City Archives’ eyewitness brochure shows bomb damage at Alter Kirchplatz in 1945. Historical buildings, wartime destruction and later reconstruction are considered for preliminary research with their available location information. Conditions at that time are then distinguished from subsequent ground changes and today’s construction plans. For a particular subarea, what matters is which findings can actually be related to it and which investigation is still needed for the planned intervention.

Working together

Allocate tasks within the construction project

Client and operator

The client describes the project and provides the available project documents. The operator adds requirements relating to use, access and scheduling. The participants agree their respective tasks and decision-making responsibilities. A coordinating contact person brings the project information together. Before an appointment, it is recorded 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 company carries out the agreed permissible investigation and documentation scope. Authority requirements and decisions are clarified with the respective competent bodies. The documents needed for a specific procedure depend on the site and project. The technical report documents the specialist service performed, including areas, depths and limits of its conclusions. Its applicability to further groundworks is checked against the specific intervention.

The local regulatory authority is responsible for hazard prevention at the project location. The state explosive ordnance disposal service at the Arnsberg district government addresses state explosive ordnance tasks for the Detmold administrative district. Gütersloh’s 2024 planning explanation names the Fachbereich Ordnung as the contact for the further measures described there. For your own project, the responsible contacts and requirements are clarified using the current procedure. The competent authorities make decisions within their respective remits.

Investigation task

Which specialist task comes next?

Determine the outstanding question for each area

An area map may summarise different findings. For the area actually affected, check the report text, existing investigation results and their limitations. A general planning area does not establish a uniform investigation requirement. The further specialist task is formulated using the respective findings and actual proposed intervention.

Assess historical documents

Coordinate an appropriate approach with the requirements

The documented knowledge, technical conditions and official requirements are considered together. Different areas may need different next steps. Selection is not based solely on a map colour. Before a private agreement, the NRW requirements for the specific activity are checked separately.

Compare investigation methods
Project types

Bring findings and working areas together traceably

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

Read the meaning of a representation from its document

Colours and hatching are used only with the corresponding legend and report text. The same colours may mean different things in different documents. A map image alone therefore does not replace technical findings. Pass on the complete source with its date and spatial reference so that its meaning remains verifiable.

If a document contains several map extracts, identify the corresponding technical findings for the area concerned. A simplified overview for the construction sequence retains its reference to the legend and report version used. If information from different documents is combined, their differing investigation purposes must remain identifiable. Missing explanations are requested from the respective issuer. Specialists can then use the complete information to clarify which findings apply to the specific groundworks.

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

Consider interventions at an area boundary separately

An excavation or route may affect several subareas assessed differently. Relate the entire planned intervention to the documented boundaries. Findings for one area are not extended to its neighbour. If identification is unclear, clarify it with the specialists involved before the decision dependent on it.

For a utility line, connection points, chambers and lateral working volumes also belong in the spatial description. These parts may affect an assessment area different from the route initially considered. Therefore state the proposed depth for each section with its relevant ground or elevation reference. Existing results are related precisely to these ground volumes. For unclear interfaces, identify the information still needed and clarify it before the affected works.

Specialist services and investigation tasks
Illustration: two people review plans and documents at a table beside a construction vehicle.

Manage other ground issues with their own evidence

Information about contaminated land, geotechnical conditions or water answers questions different from explosive ordnance assessment. Several issues may affect the same area and be relevant together in planning. Their results remain identifiable with their respective purposes. An unremarkable finding in one discipline does not replace an outstanding investigation in another.

For example, list a geotechnical report, pollutant assessment and explosive ordnance report with their respective areas covered. A laboratory result for a soil sample and the result of a technical survey serve different tasks. Site management needs the information relevant to the next intervention from each discipline concerned. Preparation keeps traceable which document substantiates which prerequisite. Outstanding investigations or official responses are assigned separately to the corresponding technical task.

Document findings and their limitations
Preparation

Prepare the scope and commission together

Historical preliminary assessment, technical investigation and specialist work during construction answer different project questions. The permissible private activity under the specific North Rhine-Westphalia procedure is clarified with the information objective and necessary authority involvement 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

The scope of private specialist work is agreed using the project documents, actual execution conditions and permissible activity. Necessary preparatory works, investigation, evaluation and documentation are described transparently. Costs and dates are related to these prerequisites and the required coordination. Changes to the construction plans are checked against the agreed contract before work is extended.

Discuss the scope and schedule
Tasks at the site

Information needed for each subarea

01

Boundaries on the site plan

Relate each finding to its corresponding map extract. The scale must show where the assessed area ends. If the planned groundworks lie at that boundary, information about the adjacent area is also needed.

02

Report associated with the finding

Record which report or official response a finding comes from. Historical assessment differs from an on-site measurement or guidance in a planning explanation. These distinctions must also remain identifiable during work preparation.

03

Conditions and limitations

Read the explanations and limitations for the marked areas. Retain this information even when preparing a simplified site overview. What a colour means follows from its respective legend; other plans may use the same colour differently.

04

Position and depth of the construction work

Draw the planned work and add its depth and construction method. If it crosses several assessed areas, the respective findings must be considered. Describe the investigation task for the affected sections using these differences.

Project documents

Documents that establish the next step

Connect the map and result with the plan version

Keep the map representation used with its corresponding text and current construction plans. Identify the relevant versions traceably. A later changed intervention is compared again with the existing boundaries. The project file should show which findings were used for which part of the actual project.

When issuing a new construction plan, identify the replaced version and areas actually changed. A moved foundation or additional trench may affect a different assessment area. Surface changes following excavation or fill are also communicated so that report depths can be related correctly. Specialists compare existing results with that plan version. A specific enquiry identifies the relevant map, its legend and location still unclear.

Hand differing requirements over to site management

If several areas are affected, their respective prerequisites must remain understandable. Site management receives complete documents with a traceable relationship to the planned works. A simplified overview must not conceal relevant differences. Outstanding clarifications are assigned to the affected area and agreed before work there.

For separately commissioned construction sections, record which report is to be used for which works. A company arriving on site later receives the corresponding plan appendices and identifiable result limitations. Following clearance work, the clearance record with its scope, results and remaining limitations is also related to the construction section actually treated and relevant plan version. Changes to accessibility, new structural elements or further groundworks needed are identified at handover. Necessary supplementary services are agreed with their permissible scope. Before preparatory ground interventions, the investigations and protective measures needed are clarified; outstanding prerequisites remain assigned to the affected section.

Construction sequence

Coordinate investigation and construction sections

Before dividing the project into working sections

Relate planned excavations, routes and other interventions to existing findings. Consider boundary areas and different depths. Organisation of the construction sequence can thereby keep technically relevant differences visible. An organisational section boundary does not replace the boundary documented in the investigation records.

Coordinate the construction phase with us

Before implementing a changed land use

A different use or changed intervention is compared with the previous findings. Show the affected areas and new plans traceably. Existing results retain their actual scope. Further technical work and official coordination follow the specific change and outstanding questions.

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 investigation task depends, among other things, on the expected objects, subsurface conditions, interference and investigation area required. Fences, utilities or existing structures can affect interpretation. A signal is therefore not classified as explosive ordnance solely on its strength. The method, interpretation and any further investigation are planned as a connected specialist task. Magnetometry measures the magnetic field passively. The magnetic effect of the target object is decisive; electrical conductivity alone does not establish its detectability by this method.

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 the mere availability of an instrument. Interfering installations, accessible areas and the required conclusion must also be considered. Results are documented with their locations and investigation conditions. Whether a supplementary method is needed follows from technical assessment and remains a specific project decision. Transient electromagnetic methods, or TDEM, evaluate the time-dependent electromagnetic response of conductive objects. The method is selected according to the investigation objective and actual measurement conditions.

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 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, 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

Match investigations to their respective areas

Read aerial photograph analysis with its map

The historical aerial photograph analysis applies to the area described in it. Read the map and results text together. An unmarked area is not automatically investigated or fully assessed. The legend and explanations are decisive.

For an older representation, also check which construction condition and state of knowledge at the time were described. Following demolition or a change of use, a new task may arise at the same address. For comparison, show the position, depth and required working volume of today’s plans. Earlier findings remain usable insofar as their documented scope matches this task. Further technical work follows the questions actually outstanding and investigation conditions on site.

Check measurement conditions on site

If a survey is necessary, the area and investigation objective are defined. Accessibility and local interference must be considered. A colour on a findings map establishes neither which measurement method is suitable nor whether the on-site measurement will be assessable. Where measurement capability is limited, suitable supplementary investigations or permissible supervision during construction are agreed on technical grounds. The selected method and its limitations are related to the specific commission.

Retain boundaries in the results plan

The clearance plan or investigation plan establishes how individual areas are to be addressed. Outstanding areas are explicitly identified. If results are later combined on one plan, the boundaries and limitations of the individual investigations must remain identifiable. The results documentation records the work actually carried out.

A new investigation records which points or areas were actually addressed and which limitations existed. If it concerns only part of the project, that scope remains identifiable in a later overall overview. Results are compiled with the agreed plan appendices and relevant elevation reference. For subsequent commissioning, identify the additional specialist service needed. The project file connects appropriate older and new documents while outstanding tasks remain distinguishable.

Next steps

Compile reports and plans for site management

01

Obtain complete reports

Obtain reports with all appendices. A forwarded map image alone is insufficient. Without a date and explanation, it may no longer be clear which question was investigated and what findings the map permits. Send the project address, investigation question and complete existing documents. Assessments and reports are checked for currency, spatial correspondence and gaps. Where historical questions remain unresolved, the necessary source research and aerial photograph analysis are carried out and related to the present-day intervention.

02

Transfer findings to the work plan

Compare the proposed groundworks with the assessed areas on the plan. Mark boundaries whose locations remain unclear and clarify them before execution. Do not use unchecked assumptions as established area information. The suitable method is agreed according to the findings sought, intervention depth, ground composition, utilities and measurement conditions. Responsibilities and execution prerequisites are clarified before work.

03

Agree outstanding tasks

Clarify with the responsible participants which questions remain open and whether further investigations are needed. Official requirements are agreed with the responsible authority. Then describe specifically which tasks the commissioned specialist company should undertake. The commission records the permissible service scope, results documents needed and execution prerequisites.

04

Perform the agreed investigation

The survey or investigation during construction appointed under North Rhine-Westphalia's requirements is carried out in the agreed areas and points. Measurement data and observations receive traceable location and elevation references. Uninvestigated areas, restricted access and relevant interference are recorded.

05

Assess survey data and findings

The collected data and findings are evaluated against the investigation objective. The technical assessment considers interference, the areas reached and remaining limits of the conclusions. It establishes which further investigation or work is needed for the planned groundworks.

06

Bring the report and plan appendices together

The report and plan attachments document the specialist works performed and their assessment. Worked areas, investigation depths, the relevant ground surface and limitations remain assigned. Reused older results and newly investigated areas are recorded distinctly. The agreed recipients receive the related documents together.

07

Hand over results with the site plan

Hand over results with the corresponding maps and appropriate plan version. Subsequent works require it to be clear which sections were investigated and where questions remain open. These distinctions also belong in a summary.

Documentation

Assess soil contamination and explosive ordnance separately

Findings and their scope

Gütersloh’s planning explanation addresses contaminated land and explosive ordnance in the same section but describes separate circumstances and requirements. Keep the respective specialist documents separate for the site as well. A finding concerning pollutants in soil does not answer an explosive ordnance question. Conversely, an explosive ordnance report does not replace a contaminated land report.

Project responsibilities

The BFR Kampfmittelräumung may provide technical guidance for planning and documentation. Applicable NRW rules and official decisions remain decisive. FONTANA-EOD undertakes the legally permissible specialist tasks agreed. Applicability of results is compared with the specific groundworks in each case.

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

Understand colours using the respective legend

A green or yellow area is only explained unambiguously by the legend and text. The map’s processing status and purpose also belong in interpretation. Therefore do not adopt a meaning from another document. If a legend is missing or findings are unclear, clarify the meaning with the responsible issuer.

Understand investigation reports and their limitations

Several findings may apply alongside each other

An area may raise soil protection, geotechnical and explosive ordnance questions simultaneously. Each assessment is read with its own basis and scope. A shared location does not make the results interchangeable. The various requirements are brought together for planning while technical responsibilities and evidence remain identifiable.

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

Frequently asked questions about subareas and findings in Gütersloh

Does a favourable assessment apply to the whole planning area?

Only if the document actually covers the entire area and intended task. Check the marked area, investigation objective and limitations. A shared project designation does not extend a result’s scope of application.

Can a map colour be adopted without its report?

Read the colour with the legend and report. If this information is missing, clarify the meaning with the issuer. The same colour may mean something different on another plan.

How should works across several assessment areas be handled?

Relate the planned groundworks to the individual areas. Different findings and outstanding questions must be considered in investigation planning. Necessary measures are agreed using the project and relevant requirements.

What does the August 2024 planning explanation establish about my property?

The explanation concerns the area of the 13th land-use plan amendment at that time. Use the location and current documents to check whether its information can be used for your property and construction works. It is not general information about Gütersloh.

What applies if a suspicious object is found despite existing documents?

Stop work in the affected area, do not touch or move the object, and keep your distance. Keep uninvolved people away. Notify the local regulatory authority or police on 110 immediately and follow official instructions.

Can a route affect several assessment areas?

Yes. Compare the entire planned alignment with the documented boundaries and findings. Conditions for one subarea are not indiscriminately extended to all other sections.

What should be done if a map has no legend?

Request the complete document or an unambiguous explanation from the issuer. A colour’s meaning is not adopted from other maps or general assumptions.

Which specialist documents and cost factors matter?

Contaminated land and explosive ordnance assessments answer different technical questions and are managed with their own documents. Even on the same area, each item of evidence retains its purpose. Effort for commissioned explosive ordnance works depends on usable earlier documents, access and preparatory works, area size or number and depth of investigation points, the suitable method, measurement conditions, and assessment and documentation. Specialist services still needed are quoted with their specific scope.

Project enquiry

Documents for your project in Gütersloh

Relate findings completely

Send the report, maps and legends with dates and the affected subareas. Also state the project address and question to be clarified by the next specialist service. Documents include complete results reports and official responses with their spatial appendices. Identify missing versions or unclear references so that they can be addressed during preparation. A current site plan shows the proposed structural elements and working areas with their respective planned depths.

Show interventions and other technical questions

Describe position, depth and construction method and include relevant documents on other ground issues with their purposes. For multiple construction sections, describe which area is accessible first and which works follow. Identify additional interventions for utilities, access or other ancillary works. The specialist company can thereby relate existing information to the desired permissible commission. For area clearance or recovery tasks, the specific scope and permissible commissioning are agreed with the responsible authority.

GPR on a construction site
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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