Technical map view of the Karlsruhe administrative district with Karlsruhe marked for explosive ordnance assessment and surveying by FONTANA-EOD

Explosive ordnance assessment in Rastatt for subareas and construction sequence

For a construction project in Rastatt, older subarea assessments, investigations carried out later and the next groundworks must align. The Kombibad case shows why an assessment of suspected ordnance and an announcement about a resolved find address different tasks. FONTANA-EOD helps project owners, designers and site managers compare complete documents professionally and carry out the investigations derived from them. Send the current ground disturbance plan with existing reports and their location appendices.

Suspected contamination

Identify the affected areas.

Sequence

Plan investigations in good time.

Result

Clarify prerequisites for earthworks.

Discuss the project's technical requirementsExplosive ordnance assessment in Baden-Württemberg
Assess the construction project

How are groundworks in Rastatt prepared with specialist input?

Planned excavations, drilling and connections are compared with existing explosive ordnance documents. Their respective investigation boundaries and limitations remain identifiable. A historical find or completed render-safe operation elsewhere does not describe the condition of your plot. The next ground disturbance is prepared using its own location and depth.

Project site

Connect the site with the specific construction task

Schematic map with a three-lion coat of arms and state colours, alongside a tablet, white hard hat, pen and notebook.

Read the Rastatt planning reference precisely

The Kombibad draft distinguishes subareas with different assessments. The bomb find resolved in 2025 is a separate historical event. For present planning, existing documents are related to the project's own area of ground disturbance. The conclusions applicable there and measures actually documented since then are decisive.

Rastatt is a major district town in the Rastatt district and the Karlsruhe administrative district in Baden-Württemberg, Germany. State the actual project address in the enquiry. The subarea assessment and later Kombibad find remain tied to their respective investigation area or find location. In surrounding areas, local responsibility follows the specific municipality; the Rastatt examples are not applied to other places.

Baden-Württemberg
Local context

From suspicion to rendering the Kombibad bomb safe

Distinguish subareas in the Kombibad draft

The draft Kombibad Rastatt development plan of 29 August 2024, corrected on 14 October 2024, cites an aerial photograph assessment by UXO PRO Consult from 2019. It distinguished suspected subareas from the rest of the investigation area and recommended further technical investigations of those subareas before ground disturbance.

Separate the resolved find from the present project

On 14 October 2025, an aerial bomb was discovered at the Kombibad construction site in Jahnallee. On 26 October, the city reported that the state explosive ordnance disposal service had successfully rendered it safe. This is a completed local event. It establishes neither a specific find nor a particular investigation obligation for other Rastatt construction areas; their own information is decisive.

The city expressly describes the object as an American aerial bomb from the Second World War. This specific historical context concerns the documented find location; it is used neither as evidence of contamination on other plots nor as a current closure notice.

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 contractor addresses the agreed assessment, investigation and documentation tasks within the necessary permit and competence framework. Its report describes the specialist services actually carried out and their limits. Official requirements and decisions are clarified with the responsible public authorities. In Baden-Württemberg, the KMBD is based at the Stuttgart regional authority. A possible find is reported to the responsible local police authority or nearest police station; they notify the KMBD. Under its conduct rules, identification and further handling remain reserved for KMBD experts. A technical report's conclusion is assessed within the specific procedure for further groundworks.

Investigation task

Which specialist task comes next?

Derive investigation needs from the specific subarea

Specialist planning considers existing historical knowledge and measures already carried out. Different assessments within an area are not merged into a general conclusion. A suitable approach is defined for the outstanding question. Investigation objective, ground disturbance depth and actual measurement conditions are considered together.

Compare suitable methods for the specific subarea

Connect a method name with its commission

The term surveying alone describes neither the area to be assessed nor the conclusion achievable. Record the question the method is intended to answer. Access, installed structures and other local conditions inform planning. After execution, results and limitations are related to this agreed scope.

Compare investigation methods
Project types

Bring subareas and stages of progress together clearly

Two people discussing plans at a table beside a vehicle on a construction site.

Provide the full spatial assessment

Send the report with its associated maps. Different conclusions within an investigation area must remain identifiable in further planning. A reduced extract without a legend may conceal boundaries between subareas. Specialist review needs the precise location of the next ground disturbance and the conclusion actually applicable there.

For several construction sections, identify current ground disturbance boundaries in the same overview. Distinguish older suspected areas, volumes actually investigated and additional working areas. This allows a targeted check of which report section concerns the next connection or excavation. If a map is missing, request it. An unclear boundary remains a query until specialists clarify its significance for the respective work.

Document spatial assessments and their limits
Two people with a tablet beside a marked construction area; plans lie in the foreground.

Describe preparatory works separately from later works

Even one ground investigation point or an early connection may disturb the ground. Mark these works in addition to the later excavation. Location, depth and sequence are compared with existing knowledge. A prepared subarea does not yet establish a conclusion for all further works of the same project.

Mark early ground investigation points, auxiliary pits and temporary working space with their planned depths. Their sequence may differ from that of the later main excavation. An adequate basis is therefore needed before the first affected ground disturbance in each case. If a point moves after coordination, the responsible participants receive its changed location. Assessment follows the new volume of ground and its coverage by existing results.

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

Establish present status from results documents

Older assessments may since have been supplemented by investigations or further measures. Request the associated reports and plans. A general announcement that an operation was successfully completed does not explain the entire investigation scope. Site management must be able to trace the areas actually addressed and remaining limitations.

Record the measures actually carried out after the older assessment and the documents evidencing them. A result includes its plan appendices, area addressed and limitations described. A later announcement does not become a broader technical conclusion merely because of its date. For the new section, explicitly identify the evidence needed and any investigation results still missing. Also record whether the report describes completion of the intended task or only an interim stage reached.

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.

An enquiry about several subareas may involve different commissions: one area may need only report appendices, while another requires an additional investigation. Describe these tasks separately. State the decision needed for the next construction phase. The quotation can then relate the assessment and investigation scope and expected results documents to the actual outstanding questions.

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.

Later access is recorded with the affected area on the plan. Agree who establishes the prerequisites and when the area will be available for specialist work. The current results are then passed on to those carrying out the work that depends on them. Scheduling thus distinguishes prepared areas, areas actually investigated and those still outstanding. Necessary official measures for a find remain separately accounted for.

Discuss the scope and schedule
Tasks at the site

Prepare investigation and construction together

01

Define the suspected subareas precisely

Do not apply a specialist assessment indiscriminately to the entire development area. The Kombibad document shows a distinction within the area investigated. Your planning requires the associated maps and complete report. This allows assessment of which proposed works actually fall within a section still needing clarification.

02

Include preparatory works in the sequence

The final excavation is not the first ground disturbance. Preparatory investigation or a utility connection may also be relevant. Identify such works in the enquiry. Agree the sequence so that necessary explosive ordnance clarification is not planned only after the respective ground disturbance.

03

Account for a possible stoppage organisationally

A programme should show who is informed of an unresolved finding and who coordinates the next steps. This does not predetermine how long a stoppage will last. Necessary measures depend on the individual case. The timing of an earlier Rastatt find cannot be applied to the next project.

04

Separate official measures from construction decisions

At Kombibad, the city coordinated the operation with the authorities involved. Closures and their lifting formed part of that specific case. A new project follows the respective instructions of its responsible authorities. A contractor or site manager must not replace an official hazard prevention measure with its own scheduling decision.

Project documents

Documents that establish the next step

Agree plan boundaries with site management

Use the same area references for investigation and execution. If the boundary of an earlier assessment is unclear, clarify it before affected works. A verbal description such as 'behind the building' is often insufficient. A common site plan helps assign the next work step unambiguously.

Include organisational consequences in preparation

Name the responsible contacts and proposed information route for unresolved findings. Possible stoppages are considered in the sequence without presuming a fixed duration. Measures taken by responsible authorities may depend on the specific situation. The programme is therefore updated with the stage of work actually reached.

Where clearance work is carried out, the associated clearance record is kept in the project file with the areas addressed.

Construction sequence

Coordinate investigation and construction sections

Clarify needs before the first ground disturbance

Assemble the current ground disturbance plan and all existing explosive ordnance documents. Mark earlier investigation areas and outstanding or unclear transitions. Specialist coordination determines the prerequisite needed before each work step. Preparatory works also receive their own identifiable reference.

Coordinate the construction phase with us

Compare the next works after a measure

Hand new results and appendices to designers and site management. Check which proposed works they cover. Additional areas or greater depths are assessed separately before work there. Completed tasks thus remain usable without silently extending the documented scope.

Coordinate the construction phase with us
Method selection

Select methods according to the task and survey conditions

Historical records and aerial photographs

A historical aerial photograph assessment is read with the images available, what they can establish and the defined investigation area. At Kombibad, the assessed subareas differed; for a current enquiry, the ground disturbance location within the associated map therefore matters. If historical questions remain open, the necessary research or additional aerial photograph assessments are actually carried out. Their results inform investigation planning. No identifiable finding in old images and a technical investigation of present ground remain different kinds of knowledge. Later measures are considered with their own reports.

Understand aerial photograph assessment

Magnetometric survey

Geomagnetic surveying passively records the magnetic field to investigate magnetically active anomalies. Detectability depends on the target object's magnetic effect; conductivity alone is insufficient. For separate subareas, define the conclusion needed, investigation space accessible and known interference. Utilities, fences and reinforcement may affect analysis. A signal is assessed by specialists and is not described as explosive ordnance solely because of its strength. Areas addressed and those still outstanding remain documented with their reference to the proposed construction section.

Understand the scope of magnetometry

Electromagnetic methods

Transient electromagnetic methods, or TDEM, investigate the time-dependent electromagnetic response of conductive objects. Suitability is justified for the specific task and site conditions. Metal installations, accessible areas and required investigation depths inform planning. If a route is added later, clarify which results already cover its location and where further knowledge is needed. Measurement data receives a spatial reference and is analysed with interference considered. An additional method is determined from this assessment; equipment availability alone does not justify its selection.

Understand electromagnetic surveying

Ground-penetrating radar

Under suitable conditions, ground-penetrating radar may provide indications of structures and reflections in the ground. Ground structure, moisture and installed structures affect assessability. Define the conclusion needed before use, for example for a changed connection location or working space to be bounded. Detected anomalies require specialist interpretation and are not automatically explosive ordnance. An unremarkable measurement image likewise applies only within the documented investigation scope. Results from other specialist tasks are read with their original questions. For explosive ordnance evidence, explicitly clarify their suitability, limits of conclusions and any additional work needed.

GPR and limitations

Deep-ground and downhole surveys

For deep foundations, shafts or boreholes, check whether investigation from the surface achieves the conclusion needed. A necessary deep-ground or borehole survey is prepared with point locations, arrangement, depths and reference elevations. Utilities and technically appropriate creation of investigation access form part of this coordination. Technical evidence, or clearance for a borehole, remains related to the space actually investigated. A moved position is assigned again before execution. General depth figures or a standard grid do not replace specialist planning matched to the ground disturbance.

Prepare deep interventions

Survey during construction

For a technically justified explosive ordnance investigation during construction, investigation steps and the construction sequence are planned together for the space actually accessible for work. This may include necessary excavation in layers, specialist exposure and additional surveys. Analysis and communication of findings form part of the agreed approach. Merely watching excavation is insufficient as detection. Site management receives the prerequisites, areas addressed in each case and subareas still outstanding. If a section becomes accessible later, its work is assessed separately. New findings are passed on before the next step depending on them.

Agree the approach during construction
Technical assessment

From a local reference to a suitable specialist commission

Use preliminary investigation as a starting point

The Historical aerial photograph analysis assesses indications from the images available. Its results relate to the area investigated and sources used. If the design extends beyond these boundaries, it provides no conclusion about that additional area. An old planning text alone does not constitute a complete technical specification.

Define the investigation scope with specialist input

For any necessary Surveying the areas to assess and investigation objective must be defined. Existing ground conditions, installed structures and possible interference are equally important. Not every method answers every question. Analysis must show where reliable conclusions were possible and which areas need further work.

Agree the approach before excavation

A Clearance plan may bring together the necessary investigation steps and execution conditions. The suitable sequence is defined using the specific project. Merely observing ordinary excavation does not replace a proper specialist investigation. A clearance method during construction requires its own technical justification and suitable prerequisites.

Any necessary area clearance is prepared for the agreed volume of ground. Findings and any recovery needs are coordinated with those responsible. The scope carried out remains documented for handover of results.

Next steps

From subarea assessments to a defined investigation commission

01

Describe the construction project clearly

Identify proposed groundworks and the planning stage. A brief description of the excavation, foundation or route helps interpretation. Enclose a site plan and planned depths. It also matters whether preparatory ground disturbance is already proposed and which works depend on others. Initial contact identifies the project location and conclusion needed. Existing plans, statements and reports are checked for currency, spatial relevance, completeness and gaps.

02

Address outstanding historical questions

Where historical questions remain open, necessary research and aerial photograph assessments are actually carried out within the commission agreed by specialists. Existing assessments are considered with their respective subareas and conclusions. Additional findings are assigned to the present area of ground disturbance and used in investigation planning.

03

Enclose existing findings in full

Send assessments and reports with all maps and appendices where possible. A press release about a find is a different type of information from a specialist report for your plot. It may identify a local event but does not describe the investigation status of your own construction area. This distinction must remain in the commission. The suitable method is selected using the investigation objective, ground disturbance depth, ground structure, installed structures and actual measurement conditions. Access and necessary prerequisites are clarified with those responsible.

04

Agree prerequisites and handovers

Clarify with those involved the information that must be available before investigation begins. This includes available utility information and known access restrictions. Also agree who receives the results. Site management then receives the relevant conclusions before the work step depending on them is due.

05

Perform the agreed investigation

The agreed survey or appropriate investigation during construction is carried out on the defined areas and points. Measurement data and observations receive clear position and elevation references. Uninvestigated areas, restricted access and relevant interference are recorded.

06

Assess and document findings

The collected data and findings are assessed against the investigation objective and actual measurement conditions. The assessment takes account of interference and limitations. The report and plan appendices document the technical assessment, areas addressed and their position, elevation and depth references. Required further tasks follow from this.

07

Assess results before the next ground disturbance

A completed operation and an adequate conclusion for all planned works are not the same. Check the report for areas covered and limitations. Outstanding points must be clarified before the affected groundworks. Changes to the project's location or depth require renewed specialist coordination.

Documentation

Who investigates and who handles a find

Findings and their scope

For Rastatt, the explosive ordnance disposal service at the Stuttgart regional authority is responsible throughout the state. Advice, searches and recovery are offered within available capacity against reimbursement of costs. Where these services cannot be provided, private specialist contractors must be commissioned. Rendering recovered explosive ordnance safe is a state duty.

Project responsibilities

FONTANA-EOD agrees the specialist services needed for the Rastatt project with you. Scope and scheduling consider the accessible investigation space, existing knowledge and outstanding prerequisites. Findings and further work follow from the actual investigation. The BFR KMR guidelines apply within their federal scope and may offer technical guidance outside it. Local requirements applicable to your project are clarified with the responsible authorities.

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.

When resuming a later construction section, compare earlier areas covered by results with the ground disturbance plan then applicable. Identify documents to reuse and the additional conclusion needed. An earlier investigation that applies spatially remains usable. New edge areas receive their own specialist assessment. Designers and contractors use the same drawing revision, including outstanding tasks before the next groundworks.

Understand the results

Use technical statements for the next decision

Distinguish the report date from execution status

A plan may reproduce an earlier investigation while further measures were carried out only later. Retain these documents with their respective dates. For the current task, trace which conclusions still apply and which results have been added. A newer plan date alone does not establish an additional investigation.

Understand investigation reports and their limitations

Provide complete results at handover

Results plans and their legends belong in the handover alongside the report. The next contractor must be able to identify areas addressed and limitations. Identify the associated ground disturbance plan and its revision. Changed works undergo specialist review before execution.

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 construction sequence and local find reports

Do closures from the Kombibad find in 2025 still apply?

The city reported the successful render-safe operation on 26 October 2025 and subsequent lifting of closures. The report described here is historical. Current city information is decisive for present restrictions.

Does the find establish contamination on my plot?

No. A find on another construction site is not an investigation of your plot. Local knowledge for the proposed ground disturbance and specialist assessment of what it establishes are needed.

When should assessment be included in the construction sequence?

Early enough for necessary investigations to be agreed before affected ground disturbance. Include preparatory ground investigations and site infrastructure works, rather than only the later main excavation.

Can the duration of handling a possible find be promised beforehand?

A reliable general duration cannot be derived from an earlier case. The finding, local conditions and necessary official measures determine the next steps.

What should be done if a suspicious object appears during works?

Stop the affected work. Do not touch, move or relocate the suspicious object, and do not uncover it further. Leave the danger area, keep others away and call the police on 110 from a safe distance. Do not take the object to a police station. Follow the competent authorities' instructions.

Why does the legend of an older results map matter?

It explains the areas and symbols used. Without these details, different assessments or boundaries may be assigned incorrectly.

Which documents show measures carried out later?

The actual investigation and results reports with their plans are needed. A general announcement about a completed operation does not replace these documents.

Which details determine the cost of a subarea investigation?

Relevant factors are completeness and usability of older reports, historical questions still open, size and depth of affected volumes of ground, access, installed structures and interference, necessary preparatory works, methods, analysis and documentation. A further subarea is defined with its specific task. Investigations carried out later are considered where their results cover present ground disturbance. Commissioning connects the technically defined scope with prerequisites actually achievable.

Project enquiry

Prepare the first technical discussion

Show subareas

Send the current ground disturbance plan with reports and complete maps.

For each report, identify the issuer, date and known area name. Enclose the legend and complete location appendices. The current plan distinguishes the main excavation, connections and preparatory groundworks. Depths and reference elevations support spatial identification. Name the next work due and the person coordinating technical questions for planning.

Add the stage of progress

Enclose later investigations with their results.

Identify works carried out since then with their actual spatial scope. Add known differences from older drawing revisions. A resolved find case and an area-specific investigation report are treated as different documents. For an outstanding construction section, assemble available results and knowledge still needed together. The specific next specialist commission can then be agreed with those involved. Identify the project location in Baden-Württemberg or the other federal state.

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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