Project pathway
The quickest route to the right decision.
Explosive ordnance surveying in the Leine-Weser administrative district
Does an older ordnance report still suit your property and proposed earthworks? Compare its drawings with today’s plots and intervention areas. FONTANA-EOD supports ordnance assessment for projects in the Leine-Weser administrative district and documents commissioned investigations.
Identify the original investigation area.
Relate former and current identifiers.
Clarify missing evidence before earthworks.
Assess the construction project
Relate old reports to today’s area
Changed plots do not alter the scope of an earlier investigation. For your project in the Leine-Weser administrative district, we compare original appendices with current intervention areas. Identify unresolved geographical references separately from missing technical findings.
Documented location references
Reference projects in the Leine-Weser administrative district
Select a project location on the map or in the location list. The associated entries lead to the protected reference overview.
The points indicate locations associated with documented references, not precise ordnance find or site coordinates. Several entries may belong to one project. References without a confirmed location assignment are available in the complete reference overview.
Map data: © BKG (2026), VG250 / GN250, Data licence Germany – attribution 2.0. Area outline assembled from official district areas and projected. Selection and project assignment: FONTANA-EOD.
Project references
Selected project examples
Twistringen: Harpstedter Straße to beyond Osterkamp – surface radar
Ordnance surveying – Twistringen: Harpstedter Straße to beyond Osterkamp – B51 through Twistringen – northern section Twistringen: Harpstedter Straße to beyond Osterkamp
Service period: 2026-08
Service areas:Surface surveys: GPR, TDEM and magnetometryMethod used in this project: Ground-penetrating radar
Project site
Connect the site with the specific construction task
Locate the individual project within the administrative district
The Leine-Weser administrative district is in Lower Saxony. For your project, identify the specific municipality, district or Hannover Region, project address and current drawing revision. Relate former and current area identifiers to the original report drawings. Local responsibilities are determined at the project location. Coordinate planned construction phases, intervention depths and additional investigations with the respective responsible parties.
Information on explosive ordnance surveying in Hanover, Hildesheim, Garbsen, Hameln and Langenhagen supports preparation of your project enquiry. Documents and planned ground disturbance on the respective property are decisive.
Local context
Which area was investigated at the time?
Regional location and historical evidence
The Leine-Weser administrative district comprises the Hannover Region and the districts of Diepholz, Hameln-Pyrmont, Hildesheim, Holzminden, Nienburg and Schaumburg. This regional classification establishes neither explosive ordnance contamination nor a particular investigation method. The individual project, existing findings and responsible authorities under Lower Saxony’s rules are decisive.
The Hameln Fire Brigade chronicle reports the air raid of 14 March 1945, with destruction near the main railway station, and the demolition of the Weser bridges in the final weeks of the war. Interpret this historical information within its location and period. A project decision today requires investigation of local findings and the specific ground intervention.
Burgdorf-Nord: former and current areas
According to the ArL’s information on the Burgdorf-Nord land consolidation procedure, its results were incorporated into the cadastral records; correction of the land register was completed in 2025. To continue using an older ordnance report, relate its original drawings to current area information. Official land consolidation records document the progress of their own procedure. Assess the ordnance investigation using the corresponding technical reports and maps. Keep both document types identifiable by their respective purposes and dates.
Requirements
Clarify technical requirements and responsibilities within the project
Relate requirements to the specialist task
For commissioned activities in Germany, the relevant specialist requirements and questions of permits, competence and responsibility are clarified. The scope of services actually planned is decisive. When searching for munitions that have been found, the scope of § 1b of the Explosives Act is considered. For relevant commercial activities, the permit under § 7 and the competence of responsible persons under § 20 are related to the specific task. The commission, allocation of tasks and required qualifications are recorded clearly before execution.
Link occupational safety to the construction sequence
The risk assessment, work areas and communication must suit the planned activities. Specialist explosive ordnance work is coordinated with other construction work. Operational organisation, site and traffic safety, and other technical specialist assessments retain their own responsible parties. Joint coordination brings the necessary information and respective responsible people together.
Use technical findings correctly
A measurement anomaly first requires specialist assessment; its appearance alone does not identify it as explosive ordnance. If an object is genuinely suspected to be ordnance, the prescribed reporting procedures and the measures set by the responsible authorities apply. Investigation reports specify the work completed and its limitations, so that results are not extended to unexamined areas or later design changes.
Identify the project location within the Leine-Weser administrative district and the specific municipality. Where area identifiers have changed, as the Burgdorf-Nord procedural information documents, bring together original and current evidence. The responsibilities for explosive ordnance contamination are assessed against existing findings and proposed works.
Within their federal scope, the BFR Ordnance Clearance guidelines describe principles for clearance planning, geophysical investigations and documentation. For the project file, link the investigation objective, actual work, results and drawings traceably.
The BFR KMR are used as technical guidance; locally applicable requirements and responsibilities must be clarified separately.
Permits, competence and responsibility for the specific activity are considered under the Explosives Act and the First Ordinance to the Explosives Act. The risk assessment in Germany under Section 5 of the Occupational Safety and Health Act relates to the planned activities. The DGUV Information 201-027 covers preventive investigation and clearance of conventional explosive ordnance and defines its scope. Its references to DGUV Rule 113-003 concern particular activities involving explosives; they are not applied indiscriminately to every construction-site investigation.
Working together
Distinguish the tasks of client, designers and specialist contractor
Client and operator
The project owner describes the project and provides the existing project documents. The operator adds requirements for use, access and timing. Project participants agree their respective tasks and decision responsibilities. Before commissioning, record which information is missing, who obtains 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 ordnance specialist contractor carries out the agreed investigation and documentation scope. Clarify official requirements and decisions with the responsible authorities. The records needed for a specific procedure depend on location and project. The technical report documents specialist works performed, including areas, depths and limitations. Check its applicability to further groundworks against the specific intervention.
Use the project address to identify the city or municipality responsible for local hazard prevention. The LGLN’s public explosive ordnance disposal service performs its state-level tasks and supports the responsible authorities. Building control handles its construction-law matters. The ArL’s regional and land consolidation duties belong to its own procedure. Bring technical commissioning and necessary official coordination together for the specific construction project.
Investigation task
Which specialist task comes next?
Clarify geographical references first
Continued use of an older report requires original appendices, current area identifiers and the new intervention. Missing geographical attribution is initially a records question. Merely choosing a new measurement method cannot answer it. Clarify which information can be obtained and which technical question remains afterwards.
Assess historical documentsThen compare the investigation scope
Even a report with an unambiguous geographical reference may not cover the required depth or a particular area. Plan additional investigation against this gap and current conditions. A new cadastral map provides orientation but no additional measurement results. Describe in the commission the findings needed for the planned works.
Compare investigation methodsProject types
Continue using reports when area identifiers change
A property has been subdivided
An earlier report may describe an area now comprising several plots. Compare the original appendices with the current subdivision. What matters is whether the actual investigation area can be traced from them. Add the new numbering to identify the relationship. It expands neither the investigated area nor the depth evidenced by the report and does not replace a missing appendix.
After subdivision, retain the former plot identifier and current areas together with their respective drawing revisions. Identify available subdivision records or surveyed boundaries as the basis for geographical attribution. Distinguish property boundaries from the area actually investigated. A report may, for example, cover only a construction phase at the time. Mark the current areas identifiable from it and where information is missing. The necessary supplement can then be discussed specifically with the original author or responsible surveying specialists.
Document findings and their limitations
A new access route lies at the edge
Working space for access may extend beyond the area previously considered. Draw the route, margins and necessary connections in the current design. Comparison identifies which parts lie within the documented investigation. A report for the same property alone is insufficient. Identify outstanding areas specifically for further technical work.
For access, compare the proposed route and working spaces alongside it with the earlier area covered by results. Include connections or temporary areas whose construction requires a ground intervention. If the old report describes only a building area, record the additional area as a separate question. Where different map revisions exist, common reference points and traceable identification of the evidence used help. Before the first intervention, technical planning clarifies existing findings and the geographical or technical investigation scope still needed.
Specialist services and investigation tasksSeveral reports concern the same site
Identify each report by its date, commission and site plan. Different documents may concern different investigation types or depths. A shared address does not make them a uniform body of evidence. An overview helps site management find the appropriate records. Retain the full results and their limitations alongside it so conclusions are not taken out of context.
A report register may identify each document’s author, date, appendix title and section covered. Distinguish original investigation results, later supplements and overview drawings alone. If an old drawing is incorporated into a new one, keep its origin identifiable. Assess overlapping investigation areas with their respective depths and limitations. Refer conflicting information back to the author or technical planners. Provide site management with the related versions so an obsolete drawing is not accidentally used for a new work section.
Document findings and their limitationsPreparation
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 taskCoordinate 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 programmeAgree a clear scope and schedule
A reliable sequence distinguishes work whose technical prerequisites are already clarified from prerequisites still outstanding. Account for partly accessible areas in the commission. Allow time in the construction sequence for results handover and assessment too. Agree scope, dates and effort for the specific task. Coordination connects access, records and execution conditions with the date a decision is needed.
Discuss the scope and scheduleRecords for comparison
Report, plots and planned earthworks
01
Original report drawing
Keep the drawing with its corresponding report. It must remain clear which representation was used during investigation. An overview added later needs its own revision and a reference to the original records.
02
Area identifiers
Compare former and current plot details where corresponding records exist. The assignment explains how the area is identified today. It changes neither the area investigated then nor the scope of the technical findings and does not replace missing geographical documentation.
03
Coordinates and reference system
Documented coordinates or surveyed boundaries require information about their reference system. If it is missing or reference points are unclear, clarify the geographical assignment. Merely shifting a sketch until it fits a new map does not locate it reliably.
04
Specific intervention area
Draw proposed groundworks on the current base plan. This distinguishes whether the old report describes the same area, covers only a section or cannot yet be located geographically. If agreement cannot be evidenced, clarify this before further use of the report.
Project documents
Documents that establish the next step
Preserve the origin of every report drawing
Identify original report drawings and later working copies clearly. A new representation may explain geographical attribution but must refer to the original report used. Identify unclear scales, missing reference systems or indistinct boundaries. This enables a specific enquiry to the author before using the document as evidence for new earthworks.
Do not silently adopt changed areas
When the construction design is revised, compare intervention limits with the documented area again. Include additional working spaces and changed depths. Pass results with the corresponding drawings to site management. The project file links commissioned measurement data, survey results and interpretation of findings to the full report and its drawings. After clearance works, the clearance record, with scope, results and remaining limitations, supplements the chain of evidence for areas actually covered. Unresolved geographical assignments must remain identifiable even if the parties change.
Construction sequence
Coordinate investigation and construction sections
Before commissioning further works
Assemble the complete report and appendices before enquiring about supplementary investigation. Identify the current construction area and unresolved geographical assignment. Technical planning can then distinguish missing records from actual additional investigation needs. The next commission addresses a specific outstanding task.
At handover to site management
Hand over the reports used with a traceable assignment to the current drawing. Site management must be able to identify the interventions to which the findings apply. An overview drawing refers to its evidence and identifies outstanding areas. Compare later design changes again before the affected earthworks.
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 assessmentMagnetometric 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 magnetometryElectromagnetic 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.
Transient electromagnetic methods, or TDEM, interpret the electromagnetic response of conductive objects over time. Define application and interpretation for the investigation objective and conditions within the proposed measurement area.
Understand electromagnetic surveyingGround-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 limitationsDeep-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 interventionsSurvey 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 constructionTechnical assessment
What the geographically assigned report actually establishes
Type of investigation
A historical aerial-photo analysis answers different questions from a technical investigation on site. Check how the results were obtained too. Agreement with a site plan does not establish that a technical investigation took place.
First identify the type of technical findings in each report. Historical interpretation has its own evidence and periods considered; a technical report describes investigations actually carried out. Their maps may therefore show different areas. Identify in a working overview the question each document answers and the findings needed for the current intervention. Geographical agreement is then not confused with identical investigation services. Missing technical results remain an outstanding task even after successful map identification.
Investigation scope
For a documented survey the method, area investigated and limitations of the results must be considered. Whether further work is needed depends on outstanding questions and site conditions. A new plot number does not, by itself, justify a change in measurement method.
For comparison, read the investigated area, depths covered and relevant surface at the time together. A later change of area identifier does not alter these details. If coordinates, a reference system or a traceable site plan are missing, clarify the evidence needed with the responsible specialists. Only then can earlier findings be compared with the new intervention. Also assess the influence of measurement conditions changed by new installations or another construction stage. Further planning identifies the area needing additional investigation.
Missing information and investigations
A new clearance plan or supplemented design must identify which results can continue to be used. If assignment to a site plan is missing, clarify the records first. If the required depth was not investigated, assess additional investigation needs.
Describe an outstanding question against the specific document where possible: which drawing is missing, which boundary is unclear or which proposed depth lies beyond existing findings? The enquiry identifies the report, date and section affected. Assign responses and additional appendices to the same project file afterwards. If geographical attribution remains unresolved, explicitly record this for the next decision. The client and technical planners can then distinguish obtaining missing evidence from additional investigation and commission the necessary tasks traceably.
Next steps
From enquiry to results handover
Assemble original records
Assemble complete reports, appendices and available map revisions. Record which file comes from which investigation. Originals and later working copies should remain distinguishable so an added representation is not mistaken for an original investigation result. For initial contact, include the project address, proposed groundworks and a contact person. We review reports and drawings for revision, geographical identification, investigation scope and missing information.
Relate former and current areas
Relate the earlier investigation area to current area information. Record missing appendices and unresolved references. This enables a specific enquiry to the author or acquisition of the additional record needed. Where historical findings are still needed, research the necessary sources and interpret available wartime aerial photographs. Relate results to today’s project area and use them for further investigation planning.
Compare the proposed intervention
Compare the position and depth of planned works with the documented investigation scope. Even after unambiguous geographical identification, a report can be used only for works its findings actually cover. Select suitable methods for necessary specialist works against the investigation objective, expected objects, ground conditions, interference and accessible areas.
Perform the agreed investigation
Carry out the commissioned survey or investigation during construction on the agreed areas and points. Give measurement data and observations traceable positional and elevation references. Record areas not investigated, restricted access and relevant interference.
Assess survey data and findings
The collected data and findings are evaluated against the investigation objective. The technical assessment considers interference, the areas reached and remaining limits of the conclusions. It establishes which further investigation or work is needed for the planned groundworks.
Bring the report and plan appendices together
The report and plan attachments document the specialist works performed and their assessment. Worked areas, investigation depths, the relevant ground surface and limitations remain assigned. Reused older results and newly investigated areas are recorded distinctly. The agreed recipients receive the related documents together.
Coordinate results and further tasks
Provide site management with the geographically assigned drawings and reports. Identify areas investigated and questions still needing clarification. A confirmation must refer to the records used and their limitations. From the results, the client, designers and site management clarify which forthcoming works are prepared within the documented scope and which additional investigations or coordination are needed before the intervention.
Documentation
Document supplements to the original report
Findings and their scope
Supplementary documentation should identify the original report used and current geographical attribution without retrospectively expanding the earlier findings. State in the report if an investigated section cannot be located reliably. Further investigation depends on the specific task and available findings.
Project responsibilities
Within their federal scope, the BFR Ordnance Clearance guidelines address assembling evidence, identifying missing data and documenting results. They provide technical guidance for other projects. Assign municipal and state duties in Lower Saxony to the respective responsible authorities. The ArL procedure documents land consolidation; document the commissioned ordnance services with their own investigation scope and results.
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 taskThe 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
A new number is not a new investigation
Cadastral updates and investigations document different matters. One describes today’s area identifier, the other the area technically investigated. Relate both traceably for continued use. A new plot number alone makes the old report neither worthless nor more comprehensive.
Understand investigation reports and their limitationsRead the finding with its accompanying drawing
A short statement of results may be misunderstood without its accompanying map. Only the commission, investigation and drawing establish its geographical and technical scope. Request missing pages rather than supplementing them from neighbouring investigations. Keep uncertainty explicit where boundaries cannot be reconstructed.
Understand the service scopeDesign and findings
Documents for the next construction decision
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 assessmentSpecialist 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
Further technical topics
Further technical information for your project
Determine the specialist service from the planned groundworks
Historical assessment, technical investigation and further work answer different questions. Your enquiry describes the planned intervention, existing findings and decision needed. This enables the required scope of specialist services for the project to be defined.
Compare servicesCoordinate the project sequence with everyone involved
Preparation connects the commission, site work and handover of findings. Changes to the project can then be incorporated into technical coordination in good time.
Process and documentationQuestions from planning
Older reports and changed plots
Does a new plot number make an ordnance report unusable?
Not automatically. What matters is whether the investigated area can still be located reliably and whether the technical findings suit the proposed intervention. A new number alone neither invalidates a report nor expands its investigation scope.
Can a current cadastral map replace the old report drawing?
It may help comparison. The original drawing nevertheless remains part of the evidence provided at the time. If it is missing or the relationship cannot be traced, clarify that gap; a later drawing that appears to fit does not establish that the earlier investigation occurred.
Is an unchanged property address sufficient to identify the area?
No. An address alone does not adequately describe the area investigated at the time. The drawings and documented investigation scope are decisive. Account for sections, later changes and different intervention depths.
Does the Office for Regional Development grant ordnance clearance?
The ArL carries out land consolidation. Explosive ordnance falls under Lower Saxony’s allocation of responsibilities to municipalities and the explosive ordnance disposal service (KBD). Updating cadastral records does not replace a necessary ordnance investigation.
What should I do if a suspicious object is found in the ground?
Stop the affected work, do not touch or move the object, and move away. Keep others away and notify the police immediately on 110. Follow official instructions; do not investigate or transport the object yourself.
How are reports assigned after property subdivision?
Compare the original investigation areas with current area information using the complete appendices. A traceable assignment identifies both versions. It does not change the technical scope of the original report.
Does an unclear map require immediate new surveying?
First clarify which original records and reference points are available. This establishes which findings remain usable and whether a technical gap remains. Additional investigation requirements follow from this task and the proposed intervention.
What affects the work involved in comparing older records?
Completeness and legibility of appendices, geographical identification and differences between earlier and proposed interventions are important. Availability of the original author and necessary additional investigations may also affect the sequence.
Project enquiry
Have older reports reviewed for your project
Send the original and current base records
Provide complete reports with all maps and appendices. Include a current site plan of the groundworks and depths. Identify former and current area identifiers and unresolved references. Include the municipality, project address and plots, and construction areas, routes or borehole positions affected. Also state which earthworks are to start first and which areas are not yet accessible. Necessary preparatory works and results handover can then be coordinated in time.
Identify the next decision
State what the report will be used for and when the findings are needed. Identify the design contact and changes from the earlier project. State the construction phase, date, official conditions and proposed construction methods. Existing utility and as-built drawings and aerial photograph analyses help technical preparation.
Surveying methods
Surveying methodsProject process
Project processIdentify the project region and location
Identify the project region and locationUnderstand the construction task and project setting
Understand the construction task and project settingFurther work on an assessed finding
Further work on an assessed finding
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.
