Technical map of the Neunkirchen district with Neunkirchen marked for explosive ordnance assessments and surveys by FONTANA-EOD

Explosive ordnance surveys in Neunkirchen (Saar)

Are you planning alterations or a change of use at business premises in Neunkirchen (Saar)? FONTANA-EOD helps project owners, specialist designers and site management compare existing ordnance reports with today’s areas and new intervention depths. Send a site plan, complete earlier reports and the planned ground works so that gaps in the initial information and investigations needed can be identified before the intervention.

Land-use history

Collect old business site plans and records of later alterations.

Ground conditions

Show known foundations, utilities and track remains on the plan.

Documentation

Compare the earlier investigation with the new ground interventions.

Discuss the change of use and investigationExplosive ordnance assessment in Saarland
Assess the construction project

Which records are needed to assess former business premises?

Collect existing ordnance reports, historical indications and current ground intervention plans. Also mark known foundations, filled structures and disused utilities. Each report is read against its own investigation question. Ordnance planning depends on statements about the specific area and planned depth; a general description of former industrial use is not sufficient.

Project site

Connect the site with the specific construction task

Outline and coat of arms of Saarland on a map, with a safety helmet, tablet, notebook and pen alongside.

Clearly assign business premises and construction sections

Neunkirchen is the district town of the Neunkirchen district in Saarland. For the enquiry, your own records on former uses, known structures and planned ground interventions are brought together. Specify the actual project address, plot and affected parts of the premises. Innenstadt, Wiebelskirchen, Furpach, Heinitz, Hangard, Kohlhof and Ludwigsthal help locate the site; the investigation relates to the defined work area. Enquiries from Spiesen-Elversberg, Schiffweiler, Illingen, Ottweiler, St. Ingbert or Saarbrücken are assessed according to their own project location and the responsible municipality. Existing findings remain linked to the relevant maps and boundaries. Further locations are classified in the regional overview. For Neunkirchen, commercial changes of use, railway and route works and renewal of utility networks are prepared according to their actual location and depth.

Saarland
Local context

Ironworks, wartime effects and subsequent property changes

Industrial history and today’s task on the property

The Altes HüttenAreal still makes Neunkirchen’s industrial past visible today. Preserved industrial installations and their current cultural use show different phases of use. Old business site plans and alteration records help trace a property’s history. To assess suspected ordnance, specific wartime effects and their assignment to the affected area are examined.

The Saarland industrial heritage portal documents severe damage to the Neunkirchen ironworks from air raids on 30 November 1944. Operations then had to stop; from 15 July 1950 the works gradually returned to operation. Local war damage and subsequent reconstruction are different time periods for historical research. They are compared with aerial photographs, business site plans and today’s ground intervention areas. The investigation status of an individual plot can be established from the history of the whole works only through this spatial assignment.

The planning note for Grubenstraße in Heinitz

The 1st partial amendment to development plan no. 45 “Grubenstraße” in Heinitz (version dated 9 January 2017) contains no specific ordnance indications for the planning area in its notes. At the same time, it describes an old air raid shelter for which RAG had no further information about the degree of filling at the time. Information on an underground structure and its condition must therefore be distinguished from the ordnance assessment. For new earthworks, bring together the exact location of the intervention and the corresponding reports. The statement at the time remains tied to the knowledge then available and this defined planning area. For today’s works, later reports and changes to the subsurface are also considered.

The associated planning statement dated 9 January 2017 describes the planned commercial development on a former coal storage area and the resulting changed access to Grubenstraße. Asphalt surfaces, earlier excavations and deposits are listed among the conditions at the time. Such information helps examine later ground interventions in time and space. Stability in areas of near-surface mining, existing air raid shelters and ordnance are separate specialist questions. The specialist designers involved bring their results together for the actual construction task; each question and limit of interpretation remains identifiable.

Read reports against their respective questions

When a site changes use, first distinguish what is known about wartime effects from the changes that took place later. Information on foundation remains, made ground or disused utilities is distinct from evidence of an ordnance item. The project owner and designers should assess existing reports together, noting which question was investigated in each. A contaminated land report does not automatically contain a reliable statement about ordnance.

Working together

Commission, site management and state hazard response

Client and operator

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

Planning and construction management

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

Specialist company and competent bodies

The private explosive ordnance specialist carries out the agreed investigation and documentation. Documents needed for an official procedure are determined by the site, project and requirements of the competent body. The technical report describes the specialist service completed with its documented area, depth and service scope. The respective competent bodies make official decisions.

In Saarland, the local police authority is the lower-level hazard prevention authority. If there is imminent danger, the police provide support within their remit. The police authorities may involve the ordnance disposal service of the state police headquarters. When ordnance is found, this service performs its state tasks. Project-specific preliminary investigations and property surveys are prepared with the commissioned specialist contractor. Responses from the responsible authorities are assigned to the affected construction section and included in further coordination.

Investigation task

Which specialist task comes next?

Consider existing structures in method selection

Metal utilities, reinforcement and foundation remains can influence measurements. Whether and how the information needed can be obtained is assessed for the specific task. Communicate known obstacles and access conditions. The method is developed from the investigation objective and actual conditions; the former type of use alone does not determine a suitable method for all parts of the site.

Compare suitable specialist services

Coordinate mining and ordnance questions

Information about cavities or structural stability concerns separate specialist tasks. Identify those responsible and provide the relevant records. Ordnance planning takes relevant conditions into account but does not replace geotechnical assessment. If several services depend on one another, their sequence should be agreed before the respective interventions and recorded clearly during preparation.

Compare investigation methods
Project types

Link the new construction task to previous findings

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

Trace historical indications spatially

Old business site plans and today’s property boundaries are considered together. Check whether former building names and investigation points can be assigned unambiguously. Records of wartime effects are linked to existing ordnance reports. This creates a traceable basis for further assessment. Later changes of use are also recorded without treating them on their own as indications of ordnance contamination.

When land is subdivided, an earlier investigation area may cover several present-day plots. Obtain the appendices, legends and spatial reference of the old report as well. Former hall numbers are assigned to the current as-existing plan. Differences between the plan and actual conditions belong in the enquiry. This helps determine which earlier findings are usable for the alterations and which parts of the site require specialist supplementation.

Arrange specialist assessment of historical evidence
Two people with a tablet beside a marked construction area; plans lie in the foreground.

Base investigation needs on today’s plans

For a new excavation or utility connection, position and depth are decisive. Show which old structures will be removed and which ground interventions this requires. Specialist planning checks existing findings and defines the suitable approach. Known structures can influence the investigation and must therefore be considered during preparation.

A new connection may run outside a previously treated area or extend deeper into the ground. Show the trench, chambers, foundations and preparatory openings with their respective depths. If the ground surface has changed, the reference level of the earlier investigation is also considered. Specialist planning uses this to describe the supplementary scope needed. The mere fact that construction has already taken place on the property does not answer this specific ground intervention question.

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

Keep different results available together

Ordnance reports, ground investigations and information on underground structures retain their respective specialist meaning. Bring them together in the project file under unambiguous names. Designers and site management must be able to identify which report answers which question. Limitations are passed on with the documents; a shared filing directory does not extend the investigation scope of individual records.

For procurement, each specialist service receives a defined task: assess existing findings, investigate volumes of ground still unresolved or document completed work. Site management and subsequent trades need the associated results plans in the same version as the report. Where records conflict, it is clarified before execution which statement is reliable and which supplementation is needed. This clarification must precede the earthworks that depend on it.

Document findings and their limitations
Preparation

Prepare the scope and commission together

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 reliable programme distinguishes tasks already technically resolved from prerequisites still outstanding. If an area will be only partly accessible, account for this when commissioning work. Results handover and assessment also need time in the construction programme. Agree timing and the work required once scope, access, documents, construction conditions and the date a decision is needed are clarified.

Discuss the scope and schedule
Tasks at the site

What has changed on the property

01

Which area do the old records describe?

Assign previous business boundaries, plots and building numbers to the current plan. An old site plan can help if its assignment is traceable. If drawings are missing or areas were later subdivided, this uncertainty should be identified before commissioning a technical investigation.

02

Which structures are still present?

Describe known foundations, utilities, track remains, chambers and hard surfaces insofar as they are actually present on your property. Such structures can affect accessibility or measurement conditions. Suitable measurement methods must be assessed using the investigation task. Existing structures alone do not establish ordnance contamination.

03

What does the new construction project change?

A new hall, a different foundation or relocated drainage may affect areas not covered by an earlier report. Draw the new structures, including their depths. Compare the new ground interventions with the area previously investigated, even if the property address has not changed.

04

Which tasks are taking place at the same time?

Demolition, ground investigation, disposal and ordnance assessment need an agreed sequence. For each specialist report, check which questions it answers and where its limits lie. Where works run in parallel, it should be identified who consolidates results, reports changes and compares the next ground intervention with the available findings.

Project documents

Documents that establish the next step

Show demolition and new construction as individual ground interventions

Record the removal of existing foundations as well as the deeper works for new construction. A preparatory survey opening or connection may also trigger its own assessment need. The sequence is compared with existing findings. A drawing of the later final state is often insufficient because it does not fully show the ground works during demolition.

Link old location identifiers to today’s plan

An earlier report may refer to hall numbers or business sections no longer used today. Add an unambiguous spatial assignment and the relevant plan version. Unclear boundaries should be clarified before further use of the statements. The name of the same company or site alone does not establish that the areas investigated then match those affected now. The survey report links initial data and the investigation commission with measurement data, assessment of findings and the results plan. Where clearance work has actually been carried out, the clearance log documents its areas, depths and scope of services. The conclusion identifies which results are usable for the next ground intervention and which tasks remain outstanding.

Construction sequence

Coordinate investigation and construction sections

Start the initial assessment with an organised project file

Send the current plans together with existing ordnance records and locations of known structures. Identify which information is confirmed and which is still being checked. The first discussion assigns the available results to the new task. Missing maps or appendices are requested specifically so that an abbreviated report extract does not become the sole basis for execution.

Coordinate the construction phase with us

Hand over results before each ground work

Designers and site management need the report with its maps and limitations before preparing the associated works. Assign statements to the specific demolition or new construction phase. If intervention depth changes, coverage is checked again. Results already suitable remain usable, while additional needs are clearly described and linked to the construction sequence.

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.

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

Historical indications, measurement conditions and further investigations

Historical sources for the specific property

Historical aerial photograph analysis and other available sources are used to identify ordnance-related indications for the specific area. Not every entry in a property file has the same evidential value. Missing sources or uncertain dates must remain identifiable in the assessment. General information about the city does not close these gaps.

Where basic information is incomplete, the necessary historical aerial photograph analysis is carried out alongside review of available files and land-use plans. Uncertain dates and unavailable sources are identified as limitations. The assessment distinguishes historical wartime effects from later demolition, filling and specialist works already documented. For business premises altered repeatedly, these time periods are related to the planned work area. The investigation commission can thus describe the areas actually outstanding and the information needed there.

Measurement methods with interfering structures

Magnetometry, electromagnetic methods and ground-penetrating radar differ in their conditions of use. Where structures cause interference, it must be checked which information an investigation can provide and which areas initially remain unresolved. An anomaly in a measurement image is not an already identified explosive ordnance item.

For the survey, expected target objects, ground composition and interference are compared with the depth required. Remaining utilities, reinforcement and foundation remains may limit measurements and their assessment. Deep localised works are described with borehole points, retaining structure axes or foundation positions. A necessary deep-ground survey or borehole clearance is given a defined location and depth reference. Access and preparatory works are agreed with their technical prerequisites.

Investigation of findings and subsequent ground works

The necessary investigation of findings, area clearance or investigation during construction relate to the defined investigation area. Visual observation of excavation alone does not replace the necessary technical ordnance survey. If an item is found, the responsible authorities are notified through the intended reporting procedures. The specialist contractor does not thereby acquire the powers of an authority.

Agreed excavation supervision is linked to the suitable investigations and the specific work sequence. The scope treated remains traceable even where work proceeds by section. For necessary ordnance recovery, the specialist task and handover to the responsible authorities are clarified. The survey report and clearance log document the work actually carried out, findings and limitations. Before the next ground intervention, their results are compared with the current plan.

Next steps

Prepare the investigation for the alterations

01

Collect the files

Link former uses, investigations and drawings to the current site plan. The initial discussion records the project location, construction task and decision needed. Complete reports, including maps and appendices, are checked for their spatial and technical scope.

02

Describe the ground disturbance

Identify structures, trenches, demolition and planned depths separately. Where basic information is incomplete, the necessary historical research and aerial photograph assessment follow. Wartime effects, later alterations and today’s ground interventions are related to one another.

03

Identify missing information

Mark outstanding questions about records and areas not yet accessible. Method selection depends on target objects, depth, ground and interference. The agreed survey or suitable specialist support addresses this scope; findings and measurement limits are assessed by specialists.

04

Prepare handover

Pass results and remaining tasks to site management and subsequent trades in an organised way. The survey report, results plans and, where applicable, clearance log document the service carried out. The next decision identifies further specialist needs before the affected ground works.

Documentation

What reports on ground, mining and ordnance tell you

Findings and their scope

An ordnance assessment result does not automatically establish anything about soil contamination, bearing capacity or mining effects. Conversely, a geotechnical or environmental report does not replace an ordnance investigation. Establish who brings the different reports together in the project file and passes the results to designers and site management.

Project responsibilities

Whether in Innenstadt, Wiebelskirchen, Furpach, Heinitz, Hangard, Kohlhof or Ludwigsthal, the specific property and planned ground works matter for the investigation. Give the exact address and, where possible, plot numbers in your enquiry so that existing records can be assigned to the correct property.

For railway and route works, the actual work locations, including station surroundings, freight areas and older utility corridors, must be marked on the site plan. For redevelopment and development sites, former business uses, demolition and documented soil relocation are also considered. The project owner and specialist designers identify which of these conditions apply to their own property. The records and investigations needed for the planned ground intervention are determined from this.

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

Record the scope of an old report

Note which areas and depths the report actually covers and which plan it refers to. Supplementary appendices must be passed on with it. If today’s plots are configured differently, their location is compared with the old investigation plan. A short summary name for the site should not replace the exact boundaries of the documented result.

Understand investigation reports and their limitations

Assess construction project changes together

New connections, deeper foundations or other demolition methods are marked on the current plans. The affected specialists receive this change with its spatial reference. Existing statements can then be reused or supplemented specifically. Coordination also records which other specialist questions are affected and who provides the records needed for the next work step.

Understand the service scope
Design and findings

Documents for the next construction decision

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

Historical evidence and the current design

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

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

Specialist reports for site management

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

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

Questions about changes of use and ordnance assessment in Neunkirchen

Is every former industrial site automatically suspected of containing ordnance?

No. Previous industrial use provides information about the history of use. An ordnance assessment must consider the available historical findings and the specific area. Previous industrial use alone therefore does not establish suspicion of ordnance on every property. Agree investigation needs before the planned ground interventions. The process links records review, necessary historical research, method selection and investigation with assessment, documentation and the decision on the next works.

Can an existing contaminated land report help?

It may contain information about former use, made ground or areas investigated. Whether it also contains reliable ordnance information must be checked separately. Chemical soil investigation results are not adopted as evidence that the ground is free of ordnance.

What should be considered for metal structures in the ground?

Known structures should be described before the investigation and marked on the plan where possible. They can influence measurements. Suitable methods and remaining limits of interpretation are assessed using the investigation task and local conditions.

Does an earlier investigation also apply to a new foundation?

Only to the extent that its documented scope actually covers the new ground intervention. The project owner and designers should have the position, depth and construction method compared with the earlier investigation status. A deeper or shifted intervention may require supplementary clarification. The full report with appendices and current location and depth plans are needed.

Which authority is responsible when explosive ordnance is found?

In Saarland, the local police authority or the police and the state ordnance disposal service are involved in hazard response. If an object is suspicious: stop work, keep your distance, touch nothing and notify the police on 110.

Which factors determine investigation costs?

Research needs, area and depth, accessibility, metal structures and the suitable method determine the work required. Assessment, documentation and any investigation of findings are coordinated with the scope of services needed. Usable older reports help limit the supplementary commission to outstanding questions. State hazard response and commissioned private specialist services have their respective allocation of costs.

Why are old hall numbers compared with the current plan?

So that an earlier report can be assigned unambiguously to today’s ground intervention area. The same site name alone is not sufficient.

Which demolition works should be included in the enquiry?

All planned ground interventions, including foundation removal, preparatory openings and new connections, each with its location and depth.

Project enquiry

Discuss existing reports and new ground works

Organise records spatially

Link old reports and business site plans to today’s construction area. Add the address, plot number, plan version, available aerial photograph assessments and complete results appendices.

Assign specialist questions

Coordinate ordnance, ground engineering, existing structures and mining with the specialists responsible. Identify construction phases, timings, conditions and the date by which a decision is needed. Known access and utility conditions form part of each work location.

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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