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

Prepare an explosive ordnance survey in Herne

Groundworks on a property already in use need current as-built plans, earlier investigation results and information about ongoing operations. FONTANA-EOD supports you in Herne in clarifying ordnance investigation needs and agreeing the commissioned scope with those involved. Check whether existing evidence also covers the new utilities, shafts or foundations.

As-built records

Check the source and revision of building and utility plans.

Construction work

Mark the areas and depths of the new work.

Coordination

Identify contacts for information still missing.

Discuss as-built documents and groundworksExplosive ordnance assessment in North Rhine-Westphalia
Assess the construction project

Make the accuracy of the as-built plan traceable

A schematic drawing provides different evidence from a surveyed as-built plan. For your Herne project, we consider the source, revision and identifiable limitations of the documents. New groundworks are compared with them; unresolved location information explicitly remains outstanding. Discuss the planned groundworks and investigation results required before the first affected ground intervention.

Project site

Connect the site with the specific construction task

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

Connect the Herne online access with the local authority

The service portal identifies the General Public Order Affairs department for ordnance investigation and disposal. The access offered for the certificate of no objection leads to a login. The information needed for your own project is clarified with the competent authority. A private specialist commission remains separate from this municipal processing.

Herne is an independent city in North Rhine-Westphalia, within the Arnsberg administrative district. Projects in Herne-Mitte, Wanne, Wanne-Eickel, Eickel, Röhlinghausen, Horsthausen, Sodingen or Holsterhausen need the exact project address and an associated site plan. Identify the existing use, planned groundworks and construction phase affected. The place name enables allocation of the property, municipal procedure and work area.

For projects in Bochum, Gelsenkirchen, Recklinghausen, Castrop-Rauxel or Dortmund, the respective municipality is explicitly identified. These neighbouring cities have their own local contacts and procedures. For further projects in the Ruhr area, documents are compiled according to the actual project location and construction task. According to its own public company information, FONTANA-EOD has a presence in Wesseling; the investigation scope is agreed with each client.

North Rhine-Westphalia
Local context

Historical evidence and municipal coordination in Herne

Municipal contact for clarifying ordnance matters in Herne

The city of Herne identifies Department 44 and Section 44/1, General Public Order Affairs, for ordnance investigation and disposal. The public order office is the municipal point of contact. Keep official requirements and decisions with the project documents. Coordinate the private investigation commission with the stage of municipal processing and necessary state measures.

The city chronicle documents the first air raids in June 1940 and identifies industrial installations as targets at that time. For March 1945, it describes the demolition of bridges over the canal and Emscher. Such historical information is assigned to the present-day construction site using available records and plans. Former mining sites, spoil tips, industrial and operational areas, shunting tracks and sidings, transport and utility routes, and storage and development sites receive their actual land-use context. Within existing city-centre and housing areas, known reconstruction phases, backfilling and later soil relocation are compared with the planned excavation, foundations or utility route.

Online access and clarification of specific documents

Under ordnance investigation and disposal, the Herne service portal offers online access labelled certificate of no objection. This initially leads to a login. The city identifies the General Public Order Affairs department as responsible. Clarify with it which details of your construction project are required and whether an analysis for the property is already available.

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?

Check the basis of a finding

For each existing result, the commission, area investigated and plans used are considered. A brief note may refer to further documents but does not replace them. Clarify which original reports can be obtained. Only on this basis can it be assessed which questions remain outstanding for the new construction task.

Assess historical documents

Consider measurement conditions and the legal framework

Installations and access are considered together with the scope of findings required. A suitable approach is determined for the specific area. Private activities must also be defined within the applicable North Rhine-Westphalia conditions. A tight programme or ongoing use of the property does not justify a blanket substitute for investigations required.

Compare investigation methods
Project types

Establish reliable evidence for work on an existing site

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

Distinguish schematic details from precise information

Check whether an existing plan contains actual location and depth information or merely illustrates a route. Identify these differences in the project overview. A line drawn on a plan is not automatically precise as-built information. Missing details are assigned to the responsible contact for further clarification.

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

Describe new structures independently of existing installations

An additional shaft or new foundation is shown with its own ground intervention. Use of the property or an earlier alteration does not answer this task. Compare the proposed area with existing investigations. Their actual boundaries are retained even if the operational address stays the same.

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

Mark inaccessible areas on the plan

Areas occupied by operations or obstacles may restrict investigation. Identify the affected areas and coordination needed. A drawing of the proposed investigation scope does not establish its actual accessibility. Areas subsequently not investigated must remain identifiable in the report.

Coordinate the sequence and 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

Clarify as-built plans, new groundworks and access

01

Accuracy and revision of as-built plans

Include utilities, buildings and earlier ground interventions with the identifiable status of their documents. Check whether a drawing contains precise location and depth information or shows existing installations only schematically. Identify missing details and clarify them with those responsible. For each drawing, note whether it was surveyed, taken from as-built records or produced only as a schematic. For a utility line, distinguish known measurement points from assumed routes. Identify the contact who can clarify missing elevations, utility types or former structures. If construction differed from the plan, include available measured records and change notes. The specialist contractor needs these distinctions to prepare investigation access and achievable coverage according to the actual construction task.

02

New shafts, utilities and foundations

Describe the proposed groundworks independently of the property's previous use. These may include a new shaft, service connection or additional foundation. Show on the plan where and how deeply the work enters the ground. The term refurbishment alone does not describe this scope. Temporary construction stages, excavation boundaries, retaining works and working areas may also affect different areas from the eventual structure. Assign the proposed groundworks to the intended work sequence. If a utility route changes, show previously investigated sections alongside newly affected areas. The associated plans, sections and existing investigation results remain available together for preparation.

03

Coordinate access and operations in time

If parts of the property remain in use, accessible investigation areas and operational restrictions must be known. Identify the responsible contacts and proposed work areas. Check on site whether the investigation areas shown on the plan can actually be reached.

04

Pass changes to everyone affected

A relocated utility route or additional structure may lie outside the area originally considered. Pass on changes with an identifiable plan revision. Have it checked whether the older investigation result also covers the changed groundworks.

Project documents

Documents that establish the next step

Identify contacts for missing details

Owners, operations and specialist planners may provide different documents. Record who clarifies an unresolved location or missing report. This organisational allocation does not replace specialist assessment. It does, however, prevent unassessed assumptions being passed on as confirmed evidence when those involved change. For construction start, distinguish information available from plans still requested or necessary clarification on site. If several contractors work in parallel, each needs the documents relevant to its area. A changed plan is passed on with its date, structures affected and proposed date of use. Project management can then assign the next specialist coordination and preparatory services required specifically.

Distribute a change clearly

If a route is relocated or a structure added, those affected receive the current plan revision. Describe which areas change from the previous version. The specialist comparison follows this new task. An older investigation is not extended merely by filing a revised plan. In the project record, baseline data and existing historical documents are assigned to the current site plan with plot, route or construction-site references. Measurement data, survey results and assessment of findings remain connected with the investigation report and its plan attachments. After clearance work has been carried out, the clearance record with the actual scope and results is added. The conclusion identifies the evidence usable for the changed construction task, together with outstanding tasks and limitations.

Construction sequence

Coordinate investigation and construction sections

Before the specialist enquiry

Collect as-built plans, previous results and the current groundworks plan. Identify the source and revision of the documents. Mark unclear details and areas not available. The enquiry can then distinguish documented evidence from outstanding questions rather than treating an incomplete drawing as a complete record of existing conditions.

Coordinate the construction phase with us

Before the next groundworks

Assign existing findings to the groundworks actually planned. Consider plan changes made since the investigation. The party carrying out the work receives complete reports and current limitations. A completion note for an earlier construction phase is not transferred to the new task without comparison.

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 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.

For planned ground investigation boreholes, provide the borehole positions and starting elevations with the depth of ground intervention. Identify the ordnance information required before preparing the borehole starting point. Geotechnical investigation and evidence for an ordnance-related ground intervention serve different tasks. The agreed findings are documented in relation to the borehole position, area and specialist limitations. If borehole positions are relocated or added, the findings are compared with the plans again before the affected work.

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

Which investigation is needed before the new groundworks

Compare earlier analyses with the new plans

A historical aerial photograph analysis must be read together with other existing findings and the current construction plan. The areas and indications it addresses must remain identifiable. Clarify which areas and questions the earlier assessment covered. Only then can its result be compared with the new work.

Consider measurement conditions around existing structures

Before a surface survey the conditions of the area actually to be investigated must be assessed on specialist grounds. Installations, accessibility and other interference can affect the scope of findings. Record in the report which findings are possible and where limitations or outstanding questions remain.

Prerequisites for clearance during construction

An explosive ordnance clearance operation during construction must not be derived solely from a tight programme. The specific prerequisites for private procedures in North Rhine-Westphalia must be observed. Visual observation of excavated material alone does not replace professional detection. Before the work, clarify which task may be undertaken, how it will be carried out and who is responsible.

Next steps

Agree documents and tasks before the investigation

01

Assign the documents

Record as-built plans, analyses and official notifications with their revision status. 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.

02

Describe the groundworks

Compile the affected areas, structures and proposed depths. For utility refurbishment, distinguish replacement along the existing route, additional branches, enlarged shafts and newly affected working areas and volumes. Depth information receives an understandable reference to the available plans. Describe which areas will actually be accessible by the proposed investigation appointment and where ongoing operations determine the sequence. The agreed construction sequence and investigation objective provide the basis for specialist comparison of existing results with new requirements. 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.

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

Agree tasks

Agree the investigation, prerequisites and contacts. 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.

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

Pass on the results

Hand over investigated areas, limitations and outstanding points to site management. 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

Hand over investigated areas and outstanding tasks to site management

Findings and their scope

The specialist report must describe the area investigated, evidence used and findings possible. Assign results to the proposed construction work and record further steps still required separately. If only part of the site was investigated, this boundary must remain identifiable at handover to site management too.

Project responsibilities

FONTANA-EOD documents the specialist service commissioned. Official decisions, utility information and other specialist evidence retain their own purposes. The BFR Kampfmittelräumung describe specialist planning and documentation principles; outside their direct scope, they serve as guidance and do not replace assessment of the specific project requirements.

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

Every item of as-built information needs a plan revision

A documented date helps assess later alterations and changes. It does not in itself establish the accuracy of every detail drawn. The source, type of representation and identifiable limitations are therefore also considered. Current construction plans are prepared on this basis and adjusted when new findings emerge.

Understand investigation reports and their limitations

An information gap remains an outstanding question

Missing details prove neither a particular object nor its absence. They are documented as such and clarified before work relies on them. This applies to as-built plans as well as incomplete investigation documents. A general summary must not conceal this uncertainty.

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 ordnance investigation during work on existing sites in Herne

Which authority should be involved for official questions?

The local public order authority is responsible for ordnance hazard prevention. In Herne, the service portal identifies Section 44/1, General Public Order Affairs, as the contact. The state explosive ordnance disposal service at the Arnsberg District Government supports the municipal authority. The specialist contractor commissioned coordinates its own investigation tasks with this procedural status.

Is an older investigation note sufficient?

This depends on what was investigated and documented. Check the area, depths or ground interventions and limitations it describes. A note concerning another construction phase cannot be transferred to new work without specialist comparison.

What belongs in an enquiry for utility refurbishment?

Describe the route of the planned work, additional shafts and other ground interventions. Include the as-built documents available and existing ordnance findings. Location information still unresolved or changes should be explicitly identified.

Can the entire operation continue during the investigation?

The operational areas that can remain usable during investigation are agreed for the specific project. Investigation areas, safe access and operational requirements are planned together. Necessary specialist prerequisites and official measures are incorporated into the work sequence.

What should I do about an unexpected possible ordnance find?

Stop the affected work and keep your distance. Do not touch, move or further expose the object. Notify the police by calling 110 and follow the authorities' instructions. Do not attempt recovery or investigation yourself.

How is a schematic representation identified?

Through its source, plan content and available information on accuracy. Unclear location or depth values are explicitly identified as unresolved.

Why is a contact identified for every document gap?

For each missing item of evidence, it is recorded who will obtain or clarify it. Information received is then professionally assessed for its content, source and relevance to the construction task.

Which costs and dates should be clarified before commissioning?

Pricing considers the investigation area, depths, method, interference, accessibility, preparatory services, interpretation and documentation. Clarify which work is commissioned and which steps still need agreement with the city or state service. The programme needs complete documents, clarified access and the procedural status actually reached.

Project enquiry

Prepare groundworks on an existing site in Herne

Identify revision and source

Send available as-built plans and reports with their dates and known limitations. To compare two plan revisions, provide previous and current site plans and sections with the known elevation and depth information. Identify the structures, areas and depths affected and describe the changes clearly. Existing investigation results are compared with them again. Each older report needs its associated plan attachments, identifiable limitations and original investigation objective. Documents still missing are listed in the enquiry with a responsible contact.

Mark new work and gaps

Show current groundworks, unclear location information and inaccessible areas with contacts. State whether buildings, surfaced areas, densely occupied utility corridors or ongoing operations limit access. For construction phases, the results needed first and later work are identified separately. Local coordination and investigation relate to the actual project location. If construction stops or resumes, communicate new plans and identifiable changes to the site. This establishes which earlier results fit the current task and which specialist questions still need work.

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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