Project pathway
The quickest route to the right decision.
Explosive ordnance survey for brownfield and former sites
On a brownfield or former site, fill, demolition remnants, utilities and earlier installations can make explosive ordnance surveys more difficult. FONTANA-EOD checks the actual site condition and your planned earthworks against existing documents. Investigation areas, suitable methods and unresolved zones can thus be defined before demolition or new construction. Send the site plan, known previous uses, depths of intervention and existing reports for technical coordination.
Assess previous use and the suspected hazard.
Clarify interfering objects and survey limitations.
Prepare excavation and documentation.
Project situation
Clarify survey obstacles and investigation limits before earthworks
Before work on a brownfield site, the explosive ordnance investigations needed for the planned ground interventions are clarified. Existing documents are checked against access, fill, demolition remnants, utilities and depths of intervention. An area that can be walked over does not necessarily allow unrestricted surveys; methods and investigation areas are defined according to actual conditions. Inadequately investigated zones and possible further steps are documented spatially for designers and site management.
Technical terms
Technical terms for brownfield and former sites
For brownfield and former sites, project developers, designers, environmental and ground specialists, site management and construction teams must use the same area, depth and documentation references.
The history of use describes previous building, commercial, military or infrastructure uses that may be relevant to a suspected explosive ordnance hazard, fill and survey feasibility.
Clarify the term in the project contextThe suspected hazard is established from historical data, aerial photographs, circumstances of finds, historical plans, authority conditions or structural traces. It is not inferred indiscriminately from the present surface.
Clarify the term in the project contextSurvey feasibility depends on sealed surfaces, vegetation, rubble, scrap metal, utilities, foundation remnants, ground conditions, access and planned investigation depth.
Clarify the term in the project contextThe depth of intervention describes how far boreholes, foundations, retaining structures, utility trenches, excavations or remediation work extend into the ground.
Clarify the term in the project contextMetal or structural objects can affect survey signals, such as reinforcement, rails, foundation remnants, scrap metal, cables, pipes or installed components. Slag and heterogeneous fill can also change survey conditions. These sources of interference are considered during planning and evaluation.
Clarify the term in the project contextThe purpose of the documentation defines whether documents are needed for procurement, the project file, site management, remediation planning, operator communication or a specific subsequent decision.
Clarify the term in the project contextUse and area
Assess brownfield and former sites according to condition, use and intervention
Fill, vegetation, remaining structures and old utilities influence access and survey conditions. For each planned intervention, it is assessed which investigation can cover the required volume of ground.
Land-use history
Brownfield and former sites may have previous commercial, industrial, storage, transport or infrastructure uses. These uses are assessed only as specifically as documents and project information permit reliable conclusions. Indications of previous uses are checked against present construction sites, planned drilling points and construction phases.
Site conditions
Vegetation, rubble, sealed surfaces, foundation remnants, ground slabs, fences and stored materials determine whether a meaningful area survey is feasible or whether access, preparation and occupational safety first need clarification. Visible vacancy says little about technical investigation feasibility or ground conditions.
Fill
Heterogeneous fill is often a central challenge on former sites. Construction rubble, scrap metal, slag, concrete, utility remnants or foreign material affect survey data, excavation sequence and assessment of findings. It must therefore be clarified in advance whether survey methods can provide sufficiently meaningful results or whether monitoring during construction is the more appropriate technical approach.
Old utilities
Disused or unknown utilities, chambers, ducts and cable routes can create technical interference. For explosive ordnance surveys, it matters whether such structures are known, suspected or identifiable only during excavation. Utility plans and site inspections can substantially improve subsequent method selection.
Removal of sealed surfaces
Necessary investigations and protective measures are planned before the ground interventions involved in removing sealed surfaces or foundations. After breaking out, changed survey conditions may enable supplementary surveys. The areas previously subject to limitations and the areas or depths investigated afterwards are documented separately by construction phase.
Borehole locations
Environmental, ground investigation and foundation boreholes involve localised deep interventions. Drilling-point investigation needs precise position, design depth, drilling method, access and surroundings information. Particularly on former sites, an individual drilling point may have different requirements from a neighbouring area with a shallower intervention.
Soil replacement
Soil replacement, remediation and excavation move large amounts of material and may reveal indications of a suspected hazard only during execution. Explosive ordnance assessment must clarify which sections are to be surveyed in advance, which are to be supervised and which findings are to be documented. Investigated and unresolved volumes of ground are recorded by position and depth.
Site development
New roads, utilities, chambers and utility connections often cross brownfield sites in long sections. These routes need their own assessment because depth, width, construction sequence and interference environment may differ from the rest of the area. A route assessment prevents linear interventions from being lost within an overall site assessment.
Interface with contamination work
Contamination investigation and suspected explosive ordnance hazards concern the same drilling points or excavation areas but have different assessment objectives. A clear interface helps coordinate environmental work, ground investigation, demolition and explosive ordnance assessment in practice. Required investigations and protective measures are coordinated with the specialists involved before exploratory drilling and excavation.
Access
Areas inaccessible to vehicles, dense vegetation, slopes, rubble heaps or unstable ground can restrict survey and supervision work. These conditions should be documented before technical method selection. Access is incorporated into method selection, execution planning and documentation of investigation limits.
Procurement documents
For construction and civil engineering services, the area, depth and supervision intended must be identifiable. Unclear requirements often lead to variations, delays or outstanding questions during construction. A structured explosive ordnance assessment provides a basis for tendering, site management and project management.
Communication of findings
If an unexpected suspicious object is found, stop work in the affected area immediately. Do not touch, move or further expose the object. Leave the immediate area and keep others away without putting yourself at risk. In Germany, notify the police immediately on 110; outside Germany, use the local emergency reporting procedure. The competent authorities determine the next steps. Inform site management and the client; internal reporting must not delay the emergency call. Contacts and procedures for findings are defined before work begins, including for trades working simultaneously. Instructions and the affected construction section are recorded without approaching the object.
Documentation limits
Documentation is only as reliable as its area, depth and method references. Particularly on former sites, it must remain clear which subarea was investigated and which later interventions need a new assessment. A conclusion for a ground investigation borehole does not replace an assessment for a later excavation.
Development potential
The explosive ordnance survey supports the question of how a brownfield site can be developed safely. It does not replace environmental or ground investigation, but relates their interventions to specialist assessment of the suspected explosive ordnance hazard. This provides a reliable basis for regeneration, tendering and construction.
Applications
Typical investigation areas on brownfield and former sites
Brownfield and former sites often consist of very different subareas. Explosive ordnance assessment must therefore consider project function, depth of intervention and technical sources of interference separately.
Unclear previous use
Former operational areas, storage yards, rail connections, production areas or military uses may give rise to indications of a suspected hazard. Traceable spatial assignment to present construction sections is decisive.
Have previous use assessedFill and scrap metal content
Heterogeneous fill, slag, rubble, metal remnants and old utilities can affect survey data. Survey feasibility must therefore be assessed realistically before execution.
Assess the former site in context
Boreholes and excavations
Ground investigations, piled foundations, retaining structures, chambers and excavations involve localised or deep interventions in areas with unclear ground conditions.
Clarify position and investigation depth
Soil replacement and remediation
Where soil is excavated, replaced or moved in batches, explosive ordnance assessment should be incorporated into the remediation and excavation sequence.
Clarify survey work during construction
Findings and recovery
Survey anomalies assessed by specialists undergo a targeted follow-up investigation or exposure. Recovery of confirmed explosive ordnance is coordinated with the permitted scope of activities, local responsibilities and documentation. If an unexpected suspicious object is found, stopping work, keeping a safe distance and immediate reporting apply.
Clarify the procedure for findings with specialists
Documentation for regeneration
Regeneration projects need verifiable documents for the project file, site management, owners, consultants, communication with authorities and subsequent use.
Prepare evidenceDecision situations
Decision situations on brownfield and former sites
On brownfield and former sites, an early assessment determines whether documents, survey work, drilling-point investigation, excavation supervision or handling of findings suit the current project stage.
01
Regeneration before planning
Before reorganisation or marketing, an initial document review can clarify whether subareas are relevant to explosive ordnance assessment.
Have your brownfield site assessed by specialists02
Demolition and site preparation
Building demolition, removal of sealed surfaces and site clearance can expose old foundations, utilities, scrap metal and fill. The investigation should be planned before ground interventions.
Determine the investigation before demolition and site preparation03
Contamination and ground investigation boreholes
Exploratory boreholes involve targeted ground interventions. Where a suspected hazard exists, drilling points and design depths should be coordinated with specialists beforehand.
Request an assessment of borehole locations04
Utility installation and site servicing
New utilities, chambers, drainage and access roads create routes with changing depths. Investigation areas should be prepared with a route plan and construction section.
Select suitable methods for utility installation and site servicing05
Excavation and soil replacement
For large-area excavation, separation or soil replacement, the suitability of explosive ordnance detection during construction is assessed. Technical investigation and assessment of each working layer are included in the construction sequence before controlled removal.
Clarify survey work during construction06
Findings during execution
If an unexpected suspicious object is found, stop work in the affected area immediately. Do not touch, move or further expose the object. Leave the immediate area and keep others away without putting yourself at risk. In Germany, notify the police immediately on 110; outside Germany, use the local emergency reporting procedure. The competent authorities determine the next steps. Inform site management and the client; internal reporting must not delay the emergency call.
Coordinate procedures for findings and documentationProject decision
Define investigations for the planned ground interventions
The next technical step follows from indications of a suspected hazard, available documents, access, depth of intervention, interfering objects and documentation needs.
Unclear previous and interim use
Brownfield and former sites may have been altered several times. Old buildings, earth movements, storage areas or technical installations must be considered alongside current planning and the depth of intervention.
Have the history of use assessedFill and demolition remnants
Rubble, slag, foundation remnants, steel components, cables, pipes and foreign material can affect both the suspected hazard and survey quality.
Determine a suitable investigationDrilling and deep interventions
Geotechnical boreholes, piles, retaining structures, chambers or excavations may reach investigation areas that cannot be adequately assessed by near-surface methods.
Agree drilling points and target depthInterface with contamination work and ground investigation
Where contamination investigation, soil replacement or geotechnical investigation is planned, the explosive ordnance implications should be clarified before ground intervention.
Check the ground investigation interfaceExcavation and site preparation
For areas that cannot be adequately investigated in advance, the technical suitability of explosive ordnance detection during construction is assessed. Each working layer is technically surveyed and assessed before controlled removal. Removal in layers and supplementary visual inspection alternate with renewed technical investigation until the agreed excavation base is reached. Excavation layers, stopping points, authority to give instructions, reporting procedures and documentation are defined before work begins.
Clarify survey work during constructionDocumentation for the project file
The results must show which area was investigated, what limitations exist and which subsequent decision is technically justified.
Prepare evidenceTechnical assessment points
Technical investigation points for brownfield and former sites
Survey quality, occupational safety and the ability to document results depend on the surface, ground, existing installations, depth of intervention and access.
Vegetation and accessibility
Brownfield sites are often uneven, overgrown, littered or accessible only in sections. Access influences the survey grid, safety and execution.
Rubble and metal content
Scrap metal, reinforcement, foundations, slag and foreign material can obscure survey signals and must be considered before method selection.
Old utilities and structural remnants
Old ducts, chambers, cables, pipelines, foundations and track structures can be both sources of interference and safety factors.
Drilling points and investigation
Where a suspected hazard exists, contamination and ground investigation boreholes should be prepared with specialists using position, diameter, design depth and access information.
Excavation and separation
Soil replacement, stockpiling and remediation excavations need clear procedures for findings if suspicious objects arise during earthworks.
Data assessment
Survey data are brought together with historical documents, aerial photographs, the construction objective, sources of interference and ground conditions before a subsequent decision is reached.
Documentation
Evidence for the project file, procurement and site management
Brownfield and former sites require documentation that makes the suspected hazard, method, investigation boundary and subsequent decision traceable, rather than merely describing an individual survey. Following actual exposure or clearance work, the corresponding findings and clearance records are included in the project file.
Project information
The address, land parcels, site plan, construction site boundaries, construction sections, planned use, routes and depths of intervention are assigned to the investigation area.
Historical data basis
Aerial photographs, historical plans, previous uses, demolition information, existing reports and known conditions are brought together for technical assessment.
Methodological justification
The document describes why explosive ordnance survey, deep-ground investigation, excavation supervision or further investigation was used for the specific section.
Survey limitations and interference
Sealed surfaces, vegetation, rubble, scrap metal, reinforcement, utilities, foundation remnants and ground conditions are documented as influencing factors.
Findings assessment
Indications of a suspected hazard and findings are described with traceable spatial references so that site management and project management can assess the next step.
Follow-up decision
The documentation supports the decision on whether drilling, excavation, further survey work, recovery or continuation of construction is the appropriate technical next step.
Supporting documentation
Documentation dossier for development and regeneration
On brownfield and former sites, documentation often needs to remain usable for several participants: project developers, designers, environmental specialists, site management, owners, investors and later operators.
Area and construction section reference
Investigation areas are described separately by subarea, planned use, construction phase, depth and access.
Document and source references
Historical data, aerial photographs, historical plans, reports, site plans and utility data are documented so that the technical reasoning remains traceable.
Method and limitation references
The document describes which method was used, which conclusion it supports and which technical limitations must be considered in the assessment.
Procedures for findings and communication
Anomalies, indications of a suspected hazard and finds are linked to location references, contacts, responsibility routes and the construction sequence.
Identify further investigation needs
The results provide a basis for further investigation, construction, excavation supervision, recovery or the next project decision.
Project process
From former site to a documented project decision
A reliable sequence prevents explosive ordnance matters from being handled in a disorganised way only when excavation, drilling or procurement is already under way.
Collect project and site data
The site plan, land parcels, construction sections, planned interventions, depths, existing conditions, access and contacts are brought together.
Assess documents and the suspected hazard
Aerial photographs, historical plans, history of use, existing reports, demolition information and possible authority conditions undergo specialist review. If the historical basis is still insufficient for the planned interventions, suitable sources are researched and aerial photographs assessed. The information is related to the current subareas and supports further investigation planning.
Define methodology and investigation depth
The appropriate investigation is assessed for boreholes, foundations, utility trenches, excavations, remediation or site preparation.
Carry out surveys or supervision
Survey work, borehole survey, deep-ground survey or excavation supervision are coordinated with the construction sequence, exclusion areas and access. The commissioned field investigation is carried out on accessible areas; survey values and their spatial references are recorded. During supervision, the interventions actually observed are documented. Uninvestigated subareas and relevant interference remain identifiable in the records.
Assess findings by specialists
Anomalies, indications of a suspected hazard and exposed findings are spatially assigned and entered into the agreed communication procedure. The recorded data and observations are assessed by specialists in relation to the investigation objective and existing interference. The result records traceable conclusions and remaining uncertainties and identifies any further investigation needed.
Hand over documentation and the subsequent decision
Reports, plans, photographs and the technical assessment are compiled for the project file, site management and the next construction phase.
Technical details
Plan investigations for demolition and new construction sites
Technical planning links documents, depth of intervention, survey feasibility, construction sequence and purpose of the documentation.
Demolition, site servicing and later construction sites are included in the investigation plan with their respective volumes of ground affected and depths.
For method selection, previous use, demolition condition, fill, existing utilities, access, depth of intervention and the assessment required are recorded. FONTANA-EOD checks available documents, survey feasibility and survey limitations against the construction sequence and purpose of the documentation. The results show which volumes of ground were investigated and which further investigations are needed before drilling, excavation or handling of findings.
Site history
Previous use, alterations, demolition and fill are checked against present-day planning.
Depth reference
Boreholes, foundations, chambers and utility trenches are assessed according to design depth and construction method.
Interference sources
Scrap metal, reinforcement, utilities, foundation remnants and foreign material are considered before method selection.
Construction sequence
Survey work, assessment of findings and documentation are incorporated into project phases, access arrangements and exclusion areas.
Select an investigation
Adapt investigations to the actual condition of the brownfield site
Check documents against remaining structures and fill
Historical plans and existing results are compared with present access, foundation remnants, utilities and ground changes. Planned interventions are defined by position and depth. This shows which documents help and where additional investigations are required.
Compare documents with existing structures and new interventions
Record survey limitations and later access in the sequence
Vegetation, construction rubble remnants, sealed surfaces and metal installations can restrict individual methods. Zones that cannot yet be adequately investigated are given their own spatial reference. The supplementary methods or later investigation timings technically appropriate for them are defined.
Coordinate methods with survey limitations and later accessProject conditions
Investigation questions before execution, procurement and site management
Before execution, documents, subareas, depths, sources of interference, working times and required documentation are recorded.
Available documents before execution
For investigation of a brownfield or former site, existing documents are checked against the current construction project. The site plan, aerial photographs, historical plans, reports, utility data, demolition information, construction phases and planned depths are cross-checked to define investigable subareas. Missing documents are considered within the project context and are not replaced by blanket assumptions.
Bring documents together into traceable subareasSubareas and construction sections
Brownfield and former sites are often developed in sections. Work along a route, a group of drilling points, a demolition area and a later building construction area may have different investigation objectives. Subareas, construction sections, depths and subsequent decisions are therefore described separately so that site management and designers do not have to work with imprecisely defined overall areas.
Define subareas clearlyAccess and surface condition
Vegetation, stockpiles, sealed surfaces, rubble, site fences, containers, existing traffic or ongoing demolition determine whether an area is technically accessible. Access influences the survey grid, equipment use, occupational safety and scheduling. Before execution, it should therefore be clarified which areas are freely accessible and which can be assessed only after demolition or site preparation. Necessary investigations and protective measures already precede the ground interventions involved in demolition or site preparation.
Coordinate accessInterfering objects and signal quality
Steel remnants, reinforcement, utilities, rails, foundation components, slag, scrap metal, recycled material and electromagnetic influences can alter survey data. These sources of interference are considered during method selection and evaluation. This makes it possible to trace which conclusion a method can support and where supplementary investigation becomes necessary.
Assess the methodology in technical termsDeep interventions and borehole positions
Geotechnical boreholes, piles, retaining structures, chambers, sumps, pits and utility trenches involve targeted ground interventions. A general area assessment is often insufficient for these points. Positions, diameters, design depths, construction methods and deviation tolerances must be known so that the explosive ordnance investigation can be planned appropriately.
Clarify position and investigation depthExcavation, demolition and construction programme
If earthworks are already scheduled, survey work, assessment of findings, exposure, documentation and possible waiting periods must realistically fit the construction sequence. Early coordination makes it easier to coordinate civil engineering teams, project management, the specialist company and responsible interfaces. It also helps reduce unclear service boundaries before work begins.
Coordinate investigation and documentation with the construction sequenceOccupational safety and site communication
Explosive ordnance matters affect access, machinery operation, exclusion areas, instruction, contacts and reporting procedures. For execution, it matters who makes site decisions, how indications of a suspected hazard are communicated and which documents site management must hold. These tasks are coordinated with site management and construction teams before work begins.
Prepare communication proceduresSubsequent decision after the investigation
At the end of the investigation, the appropriate next technical step for the commissioned area must be clear. This may be further survey work, a depth-related investigation, ordnance specialist supervision of excavation, handling of findings, documentation or coordination with competent authorities. The decisive point is that the decision remains spatially, methodologically and project-specifically traceable.
Document the subsequent decisionCoordination
What participants need before execution
Project developers, designers, procurement, site management and specialist consultants receive the plans, results and investigation limits needed for their tasks. The plan version addressed is documented for subsequent uses.
Project development
During early development, existing indications of a suspected hazard are related to the planned ground interventions. An initial specialist assessment can show which documents are missing, which subareas have priority and which services should be prepared before procurement, acquisition or a building application.
Specialist planning
Designers need reliable information on investigation areas, depths of intervention and method limitations so that boreholes, foundations, routes, excavations and demolition services can be coordinated. Required investigations are planned before the affected ground interventions.
Procurement
Clear descriptions of area, depth, method, sources of interference, documentation and procedures for findings are decisive for tendering and specifications. Unclear wording often leads to queries, delays or gaps in responsibility during execution.
Construction management
During execution, site management needs traceable investigation limits, contacts, communication procedures and document versions. Particularly during excavation, demolition, drilling and route construction, it must be clear which areas have already been assessed and where further coordination is required.
Environment and ground conditions
Contamination, ground investigation and explosive ordnance matters may concern the same area but answer different questions. For drilling, remediation, soil replacement and waste disposal, it is useful to coordinate the explosive ordnance assessment clearly with the other disciplines before ground intervention.
Operators and owners
Owners and later operators need documents that remain understandable after construction. Location references, method, investigation depth, limitations, findings and subsequent decisions should be documented so that later alterations or extensions do not have to start from scratch.
Detailed questions
Twelve questions that should be clarified before execution
Investigation planning requires areas, depths, existing information and conditions on the construction site.
01
Which subarea is affected?
Investigation of a brownfield or former site requires the actual working area as well as the address. The relevant construction section, subarea, route section or drilling-point area must be identified. Different areas may have different previous uses, depths, sources of interference and access. Clear area boundaries prevent subsequent documentation from remaining too general.
02
What intervention is planned?
Excavation, drilling, foundations, demolition, utility installation, soil replacement, remediation and site preparation create different requirements. Explosive ordnance assessment considers not just whether ground intervention will occur, but how deep it will be, which equipment will be used, in what sequence and for which construction objective.
03
What depth needs to be assessed?
The planned depth is considered together with the investigation objective, ground conditions and sources of interference during method selection. Near-surface surveys, borehole surveys, deep-ground surveys and excavation supervision address different project situations. Without the design depth, borehole diameter, foundation system, retaining structure information or excavation depth, method selection remains imprecise and may be insufficiently reliable for procurement or site management.
04
Which documents are already available?
A site plan, historical plan, aerial photograph assessment, ground investigation report, contamination report, utility plan, demolition documentation, earlier survey and authority correspondence can provide important starting points. What matters is not that every document is complete, but that existing data are brought together and checked against current planning.
05
What sources of interference are expected?
Metal installations, foundations, reinforcement, rails, scrap metal, utilities, slag, recycled material, container areas, fences and machinery can affect the technical conclusions of a survey. Sources of interference are therefore a planning matter for methodology, time requirements and documentation, as well as an execution issue.
06
What work is taking place simultaneously?
Demolition, surveying, ground investigation boreholes, utility installation, site road construction, explosive ordnance assessment and excavation may overlap in space and time. The sequence should be prepared so that investigation areas remain accessible, contacts are established and communication about findings is not lost between trades.
07
How is a suspected hazard communicated?
If an unexpected suspicious object is found, stop work in the affected area immediately. Do not touch, move or further expose the object. Leave the immediate area and keep others away without putting yourself at risk. In Germany, notify the police immediately on 110; outside Germany, use the local emergency reporting procedure. The competent authorities determine the next steps. Inform site management and the client; internal reporting must not delay the emergency call. Contacts, the stop signal and recording of instructions are defined before work begins.
08
What documentation is needed?
Procurement, site management, owners, project management, specialist consultants and later operators may need different records. Before execution, it should therefore be clarified whether location references, survey data, photographic records, assessment of findings, method limitations or a summary decision on subsequent steps are the main focus.
09
Which areas become accessible only later?
Vegetation, sealed surfaces, buildings or lack of access can limit investigations. Necessary investigations and protective measures are planned before the ground interventions involved in vegetation clearance, removal of sealed surfaces, demolition or construction of a site road. Areas accessible after site preparation are covered in a further investigation phase. Planning distinguishes between volumes of ground already assessed and areas and depths still unresolved.
10
How is drilling prepared?
Geotechnical, environmental or foundation-related boreholes require coordinates, diameter, design depth, drilling method and construction time windows. If an explosive ordnance hazard is suspected, this information should be checked by specialists before execution so that drilling points are not considered in isolation from the suspected hazard.
11
How is excavation assessed?
For areas with limited preliminary investigation, the technical suitability of explosive ordnance detection during construction is assessed. Each working layer is technically surveyed and assessed before controlled removal in layers with supplementary visual inspection follows. These steps are repeated until the agreed excavation base is reached. Working areas, excavation layers, the stop signal, authority to give instructions, communication and documentation are established before work begins.
12
What decision follows from the result?
The report records results and outstanding tasks for the next project step: further document review, supplementary survey work, ordnance specialist supervision of excavation, handling of findings, continuation of construction within the investigated area or coordination with competent authorities.
Selecting a method
Combine methods for the specific project
Selection depends on the investigation objective, required depth, ground conditions and existing sources of interference. Document review, technical investigation and assessment of findings are coordinated; results and survey limitations are documented for each volume of ground affected.
Historical aerial photograph analysis
Suitable for assessing suspected areas, previous use, wartime impacts, former buildings and spatial priorities.
Surface survey
Useful on accessible areas where the surface, interfering objects and ground conditions allow a reliable survey to be expected.
Magnetometry
Magnetometry detects ferromagnetic anomalies in accessible areas. Rails, steel remnants, reinforcement, utilities and foundation remnants can obscure survey data at the former site. Areas that can be evaluated and survey limitations are documented separately.
TDEM
TDEM detects time-dependent electromagnetic responses from conductive objects. The target object, ground conductivity, required depth and technical installations determine suitability for the particular subarea.
Ground-penetrating radar / GPR
GPR records reflections at material and structural boundaries and can provide supplementary investigation of utilities or installations. Soil, moisture, surface coupling and reinforcement affect data depth. A reflection does not uniquely identify ordnance.
Downhole and deep-ground survey
Relevant to deep boreholes, piles, excavations, retaining structures and interventions extending beyond the depth range covered by near-surface conclusions.
Excavation supervision
For areas with limited preliminary investigation, the technical suitability of explosive ordnance detection during construction is assessed. Each working layer is technically surveyed and assessed before controlled removal in layers with supplementary visual inspection follows. These steps are repeated until the agreed excavation base is reached. Working areas, excavation layers, the stop signal, authority to give instructions, communication and documentation are established before work begins.
Ordnance recovery
Survey anomalies assessed by specialists undergo a targeted follow-up investigation or exposure. Recovery of confirmed explosive ordnance is coordinated with the permitted scope of activities, local responsibilities and documentation. If an unexpected suspicious object is found, stopping work, keeping a safe distance and immediate reporting apply.
Project decisions
Which investigation comes next?
The next steps depend on whether you need to assess historical documents, prepare a specific ground intervention or use existing results for further planning.
Assess the brownfield or former site before development
Have the suspected hazard, historical documents and planned use assessed by specialists before acquisition, planning or procurement.
Have your brownfield site assessed by specialistsAssess historical evidence
Bring together aerial photographs, historical plans, previous use and existing reports for subareas.
Have historical documents assessedClarify position and investigation depth
Assess geotechnical boreholes, pile axes, retaining structures and deep interventions before execution.
Coordinate drilling points with specialistsClarify survey work during construction
Establish the suitability and sequence of construction-phase ordnance surveying for remaining excavation areas.
Coordinate survey work during constructionPrepare evidence for procurement
Structure investigation areas, the purpose of the documentation and interfaces for tendering and site management.
Prepare procurement documentsIdentify the project region
Prepare regional responsibility routes, deployment planning and the project location for the enquiry.
Check the project regionWorking approach
Approach to brownfield and former sites
FONTANA-EOD reviews construction documents, justifies method selection and documents results and investigation limits.
Check areas and depths against the construction plans
FONTANA-EOD plans the investigation using the intended intervention, existing indications of a suspected hazard and survey conditions on the site. Investigation areas and depths are coordinated with project developers, designers, site management and the commissioned environmental or ground specialists.
Have your project information reviewedDistinguish subareas on the plan
Investigation areas are considered separately by subarea, construction section, route, drilling point and planned use.
Method limitations
Survey limitations caused by vegetation, rubble, reinforcement, utilities, steel remnants or fill are incorporated into planning.
Construction sequence
Survey work, assessment of findings and excavation supervision are coordinated with the programme, access roads, exclusion areas and contacts.
Coordination
Before work begins, contacts and reporting procedures are coordinated with site management, project management, the specialists involved and competent authorities.
Documentation
Reports and plans identify investigated areas, results and unresolved areas for procurement and further planning.
Identify further investigation needs
For planned boreholes and excavation work, it is stated which questions have been clarified and where further investigation or work on findings becomes necessary.
Roles and coordination
Coordinate tasks and handovers at the former site
Brownfield and former sites often involve many participants. Technical assessment, project decisions, execution, administrative procedures and documentation should therefore be clearly assigned.
Specialist service
Private specialist company
FONTANA-EOD carries out project-specific assessment, survey work, supervision, assessment of findings and documentation within the agreed scope of services.
Project responsibility
Developer and owner
Clients provide documents, define the construction objective, depths of intervention and documentation needs, and coordinate procurement and project decisions.
Construction organisation
Planning and construction management
Designers and site management incorporate results into construction design, the construction sequence, specifications and site communication.
Specialist interface
Environmental and ground specialists
Contamination, ground investigation and explosive ordnance matters must be kept technically separate and coordinated during drilling, excavation, remediation and documentation.
Execution
Civil engineering contractors
Contractors need clear investigation areas, stopping procedures, contacts and documentation requirements before earthworks begin.
Coordination
Competent authorities
In Germany, the ordnance disposal services of the federal states and the locally competent authorities carry out hazard-response and find-management duties. Their involvement is established for the project location; outside Germany, local responsibilities apply.
The local public order authority and, where applicable, building control are involved according to their project-specific responsibilities. Conditions, contacts and reporting procedures are assigned to the affected subareas and construction sections.
Regulatory framework
Regulatory framework for development and construction
Explosive ordnance surveys on brownfield and former sites involve technical, organisational and occupational safety requirements. The specific assessment depends on the project location, suspected hazard, intervention and responsible interfaces.
In Germany, § 7 SprengG concerns the business permit for activities requiring authorisation; § 20 SprengG concerns the certificate of competence for responsible persons. Under § 1b SprengG, handling found munitions also includes searching for them. On brownfield and former sites, the required qualifications depend on the specific investigation or clearance commissioned, the planned construction condition and the allocation of responsibilities.
DGUV Information 201-027 concerns protective measures during ordnance clearance work. DGUV Rule 113-003 concerns the dismantling or destruction of explosives or corresponding objects and also includes the disposal of found munitions. It applies according to this field of activity; it does not replace a risk assessment specific to the planned ground intervention.
Explosives-law framework
For work involving explosive ordnance, the requirements of explosives legislation concerning permits, competence certification and responsibility must be observed.
Occupational safety and the construction site
Risk assessment, access, exclusion areas, instruction, machinery use and communication procedures must suit site organisation.
Specialist guidance
DGUV Information 201-027 supports risk assessment and protective measures for explosive ordnance clearance work. The Baufachlichen Richtlinien Kampfmittelräumung contain requirements for historical and technical investigation, clearance concepts, procurement and documentation within their defined scope of federal responsibilities. Their application to the specific regeneration project is clarified separately.
Interfaces with authorities
Authority conditions and coordination procedures depend on the project location and circumstances. If an unexpected suspicious object is found, stopping work, leaving the immediate area and immediate reporting take priority; in Germany, notify the police on 110, and outside Germany use the local emergency reporting procedure. The competent authorities determine the next steps.
Requirements under explosives legislation, 1. SprengV, occupational safety, DGUV references, BFR KMR and responsible interfaces are assessed for the project insofar as they are relevant to investigation, execution, communication about findings and documentation.
Prepare regulatory and documentation questionsInsights
Assess documents and record results
Historical documents and technical investigations provide different information. In the report, they are assigned to the investigated areas and planned interventions.
Aerial photographs and historical documents
Historical documents help define suspected areas and previous use of the project site.
Assess historical indications relating to the former siteDeep-ground investigation
Drilling points, pile axes and excavations need clear depth and location references.
Investigate excavations and foundationsExcavation within the construction sequence
For remaining areas, it is assessed whether explosive ordnance detection during construction is suitable. Excavation layers are technically investigated before removal.
Supervise excavation on the brownfield siteHandling of findings
Planned work on findings is coordinated with the responsible participants. For a suspicious object, stopping work, keeping a safe distance and immediate reporting apply.
Assign findings and further measuresDocumentation
Reports, plans and photographic records support site management, procurement and the project file. Following actual exposure or clearance work, the corresponding findings and clearance records are included.
Document investigated and unresolved zones
Project enquiry
The site plan, depths and construction phases enable the investigations and further documents required to be clarified.
Send former site documents for review
Further specialist areas
Specialist services for demolition and new construction sites
Depending on the project stage, the next step leads to document review, deep-ground survey, ordnance specialist supervision of excavation, documentation or a direct project enquiry. Further construction tasks can be found in the Sector overview.
Industry and commercial sites
Plan investigations for other commercial construction projects and existing sites.
Have your industrial project assessed by specialistsHistorical aerial photograph analysis
Prepare the assessment of the suspected hazard using aerial photographs, historical plans and the history of use.
Have the suspected hazard assessedDeep-ground survey
Coordinate drilling points, piled foundations and deep interventions with specialists.
Clarify intervention depthExcavation supervision
Clarify suitability and the sequence for explosive ordnance detection during construction.
Plan excavation supervisionProcess and documentation
Structure documentation for procurement, site management and the project file.
Prepare evidenceProject enquiry
Send the location, site plan, depth, construction phase and documents.
Send project documentsIdentify the project location
Relate the former site and new construction sites spatially
Identify the site and applicable requirements
The project location, property boundaries, former buildings and current construction site identifiers are maintained with traceable location references. Identify existing reports, contacts and known requirements for the respective subareas. Results thus remain assignable during phased development.
Investigation information
This information is needed for investigation planning
Investigation planning requires the working areas, depths of intervention, construction phases, sources of interference and documentation needed.
A reliable enquiry describes the affected area as specifically as possible. A land parcel, construction site boundary, route axis, drilling-point list or construction section is more useful than a broad search radius. The assessment can thus be related to the actual intervention.
Have the project information reviewedThe same area may require near-surface, depth-related or construction-stage investigation. The distinction arises from the foundation, borehole, chamber, utility, demolition or excavation. The planned depth should therefore always be stated.
Have the project information reviewedExplosive ordnance assessment is easier to plan when it is clear whether the project is at acquisition, planning, tendering, demolition, drilling or excavation stage. Each phase needs different documents, decisions and time windows.
Have the project information reviewedExisting utilities, reinforcement, concrete, rubble, steel, slag, railway remnants or stockpiles should be identified early. They influence both execution and the ability of the methods used to provide meaningful conclusions.
Have the project information reviewedBefore work begins, the purpose for which the result is needed should be clarified. Documentation for procurement, site management, an operator file, a drilling-point decision, excavation planning or a subsequent decision may require a different level of detail and structure.
Have the project information reviewedProject developers, designers, environmental specialists, ground investigation consultants, civil engineering teams, operators and competent authorities need coordinated information. A clear interface structure facilitates subsequent site communication.
Have the project information reviewedBefore execution, the procedure for indications of a suspected hazard or suspicious objects should already be clear. Contacts, work stoppage, documentation and communication of responsibilities should be known within the construction sequence.
Have the project information reviewedFor later construction phases, the project documents record which area was investigated, which method was applied, what limitations exist and which next step is technically justified.
Have the project information reviewedTechnical information
Industry and commerce: brochure
Work on industrial and commercial sites combines existing installations, operational processes and new ground interventions. The brochure explains how ordnance assessment is coordinated with these conditions.
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Project questions
Frequently asked questions about explosive ordnance surveys on brownfield and former sites
When should brownfield and former sites undergo an explosive ordnance assessment?
An assessment is useful as soon as boreholes, demolition, soil replacement, utility trenches, foundations, excavations, site servicing or regeneration are planned on a site with an unclear history of use. The suspected hazard, depth of intervention, interfering objects, access and purpose of the documentation are decisive.
Which documents does FONTANA-EOD need for an initial assessment?
Useful documents include a site plan, land parcels, subareas, planned use, demolition and construction phases, drilling points, depths of intervention, utility plans, historical plans, aerial photograph assessments, ground investigation and contamination documents, existing reports and known conditions. Authority information and conditions should be supplied with their dates, complete attachments and geographical scope.
Why are brownfield sites often technically demanding?
Brownfield sites may contain vegetation, rubble, metal remnants, old utilities, foundation remnants, fill and variable ground conditions. These factors affect survey quality, access, occupational safety and selection of the appropriate survey.
How are contamination, ground investigation and explosive ordnance assessment coordinated?
Contamination, ground investigation and explosive ordnance concern different specialist questions, but overlap in boreholes, soil replacement and excavations. Explosive ordnance assessment should take place before ground interventions so that investigation and construction are not interrupted in a disorganised way.
Which methods may be considered for former sites?
Depending on the project, historical aerial photograph assessment, surface survey, magnetometry, TDEM, ground-penetrating radar, deep-ground survey, borehole survey, ordnance specialist supervision of excavation, area clearance or explosive ordnance recovery may be relevant. Selection depends on the surface, interfering objects, investigation depth, access and construction objective.
How are inadequately investigated zones documented?
For each subarea, the plan version investigated, area, depth, methods, results and survey limitations are stated. The documents identify volumes of ground still unresolved for demolition, site servicing and new construction. Buyers, designers and site management can thus compare existing results with their specific interventions.
What role do competent authorities play if a suspected hazard or object is found?
If an unexpected suspicious object is found, stop work in the affected area immediately. Do not touch, move or further expose the object. Leave the immediate area and keep others away without putting yourself at risk. In Germany, notify the police immediately on 110; outside Germany, use the local emergency reporting procedure. The competent authorities determine the next steps. Inform site management and the client; internal reporting must not delay the emergency call. As a private specialist company, FONTANA-EOD supports project-specific assessment, survey work, documentation and communication within the commissioned service.
What determines the effort and cost of explosive ordnance surveys?
Decisive factors include site size, access, vegetation, sealed surfaces, interfering objects, ground conditions, depth of intervention, available documents, construction phase, required methods and extent of documentation. A reliable estimate can be made only after review of the project data.
Quick check
Four pieces of information that help before the first specialist discussion
State which subareas are affected, what intervention is planned and what decision is needed. Provide dates for drilling, demolition, excavation or procurement. FONTANA-EOD reviews the information and identifies missing documents and outstanding coordination.
Project location and responsibility
The project location is important for deployment planning, responsible interfaces and regional assessment. The street, municipality, land parcel or coordinates should be supplied together with contacts and site access information.
Current project stage
Whether a site is at initial development, already tendered, under demolition, undergoing ground investigation or shortly before earthworks changes the technical priority and form of response required.
Proposed ground disturbance
Excavation depth, drilling depth, utility trench base, excavation dimensions, retaining structures, pile grid and construction method determine which investigation is appropriate for the specific intervention.
Desired result
The enquiry should state whether an assessment is needed for planning, procurement, site management, drilling points, excavation supervision, the operator file or further coordination.
Preparing an enquiry
Prepare project information for the enquiry
The initial assessment requires a site plan, subareas, new use, depths, demolition and construction phases and existing documents.
Site and area
Address, land parcels, site plan, construction site boundaries, subareas, existing use and planned regeneration.
Ground disturbance and depth
Boreholes, foundations, utility trenches, excavations, demolition, soil replacement, construction method and design depths.
Available documents
Aerial photograph assessment, historical plans, utility plans, ground investigation data, contamination documents, existing reports and known conditions.
Construction sequence and purpose of the documentation
Tendering, time windows, site management, project file, HSE, procurement or a specific subsequent decision.
Submit project details together
Send the available documents together as far as possible. The project location, area, planned use, intervention, depth, construction phase and intended next step are decisive. FONTANA-EOD assesses investigation needs, suitable methods and information still missing.
+49 (0) 6843 - 999 499 7
info@fontana-eod.de
Site plan, depth, construction phase, suspicion indicators
Site management, designers, HSE or project management
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.
