Excavation is one of the most critical and high-risk activities in construction projects, forming the foundation for everything that follows. Whether the goal is to prepare for the construction of building footings, lay underground utilities, shape road subgrades, or form retaining structures, excavation sets the stage for stability, safety, and quality.
A well-prepared Method Statement provides a comprehensive, step-by-step plan that ensures excavation works are executed safely, efficiently, and in compliance with engineering standards, project specifications, and legal requirements. It serves as a formal reference for all stakeholders, including engineers, supervisors, safety officers, and operators, aligning everyone on the approved sequence of work, safety measures, quality checks, and environmental precautions. This article provides a complete excavation method statement adaptable for a range of construction applications — from shallow trenching to deep shafts and large-scale earthworks — making it a vital document for contractors and consultants alike.
2. Purpose of the Method Statement
The primary objective of this Method Statement is to define in detail the safe and correct procedure for carrying out excavation works, ensuring that all activities conform to:
The project’s technical specifications and approved construction drawings
This method statement applies to all excavation activities required in the project and can be adapted for various construction environments:
Shallow Excavations: Footings, slabs, and landscaping features, typically less than 1.5 m deep.
Deep Excavations: Basements, underpasses, and shaft constructions exceeding 1.5 m depth.
Trench Excavations: For installation of pipelines, stormwater networks, cables, and duct banks.
Roadworks & Drainage: Excavating to subgrade level, forming roadside ditches, and preparing for culverts.
Mass Earthworks: Large-scale cut and fill operations for site leveling, industrial platforms, or embankments.
The scope also includes associated activities such as:
Site clearing and grading
Surveying and setting out
Mechanical excavation using appropriate plant and equipment
Installation of shoring or slope protection
Groundwater control through dewatering systems
Disposal, stockpiling, or reuse of excavated materials
Backfilling, compaction, and surface preparation after excavation
4. Responsibilities
To ensure a smooth and safe execution, each team member’s responsibilities are clearly defined:
Project Manager: Oversees the entire excavation process, approves method statements, coordinates with the client/consultant, and allocates resources effectively. Ensures work aligns with contract requirements and project milestones.
Construction Manager: Manages day-to-day excavation operations, assigns tasks to site teams, and ensures work follows the approved method statement. Resolves on-site issues and ensures resource optimization.
Site Engineer: Responsible for accurate setting out using surveying instruments, continuous level checks during excavation, and verifying dimensions against drawings. Coordinates with the QC and HSE teams to ensure technical and safety compliance.
HSE Manager: Conducts hazard identification and risk assessments, ensures PPE compliance, arranges safety briefings (Toolbox Talks), and monitors excavation edges, access points, and shoring systems for hazards.
Quality Control Manager: Inspects excavation quality, ensures slopes and dimensions meet specifications, supervises compaction tests, and keeps accurate quality records.
Environmental Manager: Ensures excavation activities minimize dust, noise, and water pollution; monitors erosion control measures; and ensures proper disposal of waste.
Machine Operators & Skilled Workers: Operate equipment according to safety guidelines, follow instructions from supervisors, and stop work immediately if unsafe conditions arise.
5. Materials, Tools, and Equipment
The following equipment and materials are essential for excavation works, with selection based on site conditions and project requirements:
Excavation Equipment
Heavy Machinery: Excavators (crawler, wheeled, long-reach), bulldozers for clearing and pushing soil, loaders for material transport, graders for leveling.
Transport Vehicles: Dump trucks or tipper lorries for hauling material to disposal sites or stockpiles.
Shoring Systems: Steel sheet piles, trench boxes, soldier piles with lagging, or timber supports to prevent soil collapse in deep excavations.
Dewatering Equipment: Submersible pumps, well point systems, sump pumps with discharge hoses, and sediment control measures.
Surveying Tools: Total stations, GPS survey units, laser levels, leveling staffs, and measuring tapes for accurate setting out and level checks.
Hand Tools: Shovels, picks, crowbars, trowels for trimming and manual excavation in confined or delicate areas.
Safety Gear: Helmets, safety boots, reflective vests, gloves, dust masks, hearing protection, and fall protection equipment for deep excavations.
6. Work Procedure
6.1 Site Preparation
Before any excavation begins, proper site preparation is essential to ensure safe, efficient, and compliant operations. This stage involves both physical and administrative activities to make sure the site is ready for heavy equipment and workforce mobilization.
Document Review & Permits: Review all approved drawings, geotechnical reports, and specifications. Confirm the location of underground utilities by coordinating with local utility providers, and obtain all necessary excavation permits from municipal or governmental authorities.
Site Reconnaissance: Conduct a detailed walk-through of the site to identify hazards, restricted areas, and optimal access routes for machinery. Document any existing damage to nearby structures for future reference.
Clearing & Grubbing: Remove vegetation, roots, rubbish, and debris from the excavation zone. Where large trees exist near the excavation, coordinate with the environmental team to decide whether protection or removal is required.
Access Routes & Working Platforms: Construct stable access roads and platforms for excavators, dump trucks, and cranes. These should be designed to withstand heavy loads and prevent rutting or collapse.
Barricading & Signage: Install robust barriers, safety tape, and warning signs around the work area to prevent unauthorized access. If the excavation is adjacent to traffic, implement a traffic management plan with proper diversion signs and flagmen.
Utility Identification & Protection: Use ground-penetrating radar (GPR) or utility locators to identify underground services. Clearly mark these on the ground and, if necessary, protect them with timber shields or diversion works before excavation.
Site Facilities: Set up temporary site offices, first-aid stations, and welfare facilities for workers, ensuring compliance with health and safety regulations.
6.2 Setting Out
Accurate setting out is the backbone of successful excavation works. Errors at this stage can lead to costly rework, safety issues, and structural failures later on.
Control Points: Establish permanent control points and reference benchmarks based on the project’s approved survey data. These must be clearly marked, protected, and regularly verified.
Marking Boundaries: Clearly define excavation extents using lime powder, spray paint, or wooden stakes. For deep excavations, consider marking progressive depth levels along the edges for visual guidance.
Vertical & Horizontal Accuracy: Use high-precision surveying equipment such as total stations, GPS survey units, or laser levels to ensure that the excavation lines and levels match the approved design.
Offset Markers: Install offset pegs away from the actual excavation to preserve reference points in case the original markers are disturbed during the works.
Verification & Cross-Checks: Have the setting-out data independently verified by the project’s surveyor or consultant before excavation begins. This double-checking helps prevent costly mistakes.
Safety in Surveying: When working near traffic or machinery, surveyors must wear high-visibility PPE and establish safe zones for operating instruments.
6.3 Excavation Execution
This is the core activity of the method statement, and precision, safety, and sequencing are key.
Excavation Execution
Choice of Equipment: Select excavators, loaders, or dozers based on the soil type, excavation depth, and working space. For example, long-reach excavators are suitable for deep, narrow shafts, while crawler excavators handle large open cuts efficiently.
Excavation Sequence: Start excavation from the highest point and progress systematically, ensuring even removal of material to avoid instability. For trenches, work in sections, ensuring each completed section is safely shored before proceeding.
Shoring & Sloping: For deep excavations (>1.5 m), use shoring systems like sheet piles, soldier piles, or trench boxes. Where space allows, sides may be battered to a safe slope angle as per geotechnical recommendations.
Layered Excavation: Remove soil in controlled layers to maintain stability and prevent sudden collapses. Avoid undercutting or leaving overhangs.
Continuous Monitoring: Check excavation depth and alignment frequently using surveying instruments. Make real-time adjustments to avoid over-excavation or deviations from design.
Safe Working Distances: Keep heavy equipment at least 1 m away from the edge of the excavation to avoid soil collapse due to surcharge loads.
Restricted & Manual Excavation Areas: In areas near existing utilities or delicate structures, perform excavation manually to prevent accidental damage.
Night Works Precautions: If excavation must continue at night, ensure adequate lighting, reflective barriers, and supervisor presence at all times.
6.4 Dewatering
Water is a common challenge in excavation works, and effective dewatering is crucial for maintaining dry and stable conditions.
Groundwater Assessment: Before excavation, review the geotechnical report to identify the water table level and soil permeability. This will determine whether continuous pumping, well points, or other systems are needed.
Types of Dewatering Systems:
Well Point Systems for deep or extensive excavations.
Sump Pumps for localized or shallow water collection points.
Deep Wells for lowering the water table in permeable soils.
Installation & Operation: Install pumps before reaching groundwater levels to prevent sudden flooding. Position discharge hoses away from excavation edges to avoid soil erosion and re-entry of water.
Sediment Control: Pass discharge water through sedimentation tanks, silt fences, or geotextile filters to remove suspended solids before releasing it to municipal drains or water bodies.
Surface Water Control: Construct diversion channels, berms, or bunds to keep rainwater and runoff from entering the excavation.
Safety in Dewatering: Ensure electrical pumps are properly grounded and cables are protected from damage. Operators should be trained in pump maintenance and emergency shutdown procedures.
6.5 Disposal and Backfilling
After excavation, proper disposal of unsuitable materials and precise backfilling are critical for long-term stability.
Material Segregation: Classify excavated material immediately — suitable material for reuse, unsuitable material for disposal, and contaminated material for specialized handling.
Transport & Disposal: Load unsuitable material into dump trucks and transport it to approved landfill sites, keeping disposal tickets for documentation. Ensure truck loads are covered to minimize dust and spillage during transit.
Stockpiling for Reuse: Store reusable fill material in designated stockpile areas with controlled heights to avoid compaction issues. Protect stockpiles from rain to maintain moisture balance for backfilling.
Backfilling Process:
Use only approved fill materials as per project specifications.
Place material in uniform layers not exceeding 300 mm compacted thickness.
Compact each layer using appropriate equipment (plate compactors, rollers) to achieve the required density.
Perform field density tests (FDT) or nuclear density tests to verify compaction quality.
Final Grading: Shape the surface to match the design profile, ensuring proper drainage away from structures.
Documentation: Maintain records of compaction test results, disposal tickets, and backfilling progress for quality assurance and client approval.
7. Safety Measures
Excavation activities are among the most hazardous operations in construction, with risks including ground collapse, falls, contact with underground utilities, water ingress, and heavy equipment accidents. This section of the Method Statement provides comprehensive safety requirements based on recognized standards such as OSHA 29 CFR 1926 Subpart P and BS 6031, as well as best practices from industry experience.
7.1 Pre-Excavation Safety Planning
Risk Assessment: Conduct a detailed hazard identification and risk assessment (HIRA) before starting work, considering soil stability, water table level, depth, proximity to structures, and weather conditions.
Method Statement Review: Ensure all site staff are familiar with the approved method statement and that Toolbox Talks are conducted daily to reinforce safety topics.
Permit-to-Work System: Implement a permit-to-excavate process that requires approval from the Project Manager or Safety Officer before any excavation begins.
7.2 Excavation Edge Protection
Install rigid barriers, guardrails, or high-visibility fencing around all open excavations to prevent accidental falls.
Place warning signs in multiple languages if the workforce is diverse.
For night works, use reflective barricades and adequate lighting to ensure visibility from all angles.
7.3 Safe Access and Egress
Provide access ladders or steps for excavations deeper than 1.2 m, placed at intervals not exceeding 7.5 m for trenches.
Ladders must extend at least 1 m above the excavation edge and be securely tied.
Where ramps are used, ensure they are stable, non-slip, and with a maximum safe slope.
7.4 Slope Stability and Shoring Systems
For unsupported excavations, maintain side slopes according to soil type:
Stable rock: vertical sides allowed
Type A soil (clay): max slope 53° (H:V = 3/4:1)
Type B soil: max slope 45° (H:V = 1:1)
Type C soil (sand/gravel): max slope 34° (H:V = 1.5:1)
Use engineered shoring systems — such as sheet piling, soldier piles with lagging, trench boxes, or hydraulic shores — when space is limited or soil conditions are poor.
Inspect shoring daily and after every rainfall or significant vibration event.
Use ground-penetrating radar (GPR) or cable locators before digging to identify buried services.
Mark all utility lines clearly, and hand-excavate within 1 m of the marked line.
Notify utility companies of excavation schedules when working in their easement.
7.6 Heavy Equipment Safety
Operators must be licensed, trained, and authorized to operate specific equipment.
Maintain a minimum clearance of 1 m between machinery tracks/wheels and excavation edges to prevent surcharge loading.
Assign a signalman when equipment operates in tight spaces or near personnel.
7.7 Water and Flooding Hazards
Implement a dewatering plan to prevent sudden water accumulation.
Never allow workers to enter excavations with standing water unless pumps are actively running and the water source is controlled.
Provide life vests if working near deep water bodies.
7.8 Atmospheric and Confined Space Hazards
For excavations deeper than 1.5 m, test the atmosphere for oxygen deficiency, flammable gases, and toxic vapors before entry.
Provide forced ventilation if air quality is inadequate.
Follow confined space entry procedures when required, including standby rescue personnel.
7.9 Spoil and Material Storage
Store excavated material at least 1 m away from excavation edges to reduce the risk of collapse.
Keep spoil piles stable, and cover them if heavy rain is expected to prevent erosion and runoff into the excavation.
7.10 Emergency Preparedness
Maintain an excavation rescue plan on-site, including available rescue equipment, contact numbers, and first-aid-trained personnel.
Ensure all workers know evacuation routes and muster points.
Conduct regular safety drills simulating potential emergencies such as collapse, flooding, or gas leak.
7.11 Weather and Environmental Considerations
Suspend excavation works during heavy rain, flooding, or high winds that may cause soil instability.
Reassess stability after severe weather before resuming work.
8. Quality Control Procedures
Quality control in excavation works is essential to ensure the accuracy, stability, and long-term performance of the constructed facility. Proper QC procedures prevent structural defects, settlement issues, and costly remedial works. This section details all inspections, tests, and documentation requirements to maintain high standards and full compliance with project specifications and applicable codes.
8.1 Pre-Excavation Quality Checks
Document Review: Confirm that the latest approved construction drawings, specifications, and method statement are available on site.
Survey Benchmark Verification: Check the integrity, position, and elevation of all control points and benchmarks before starting.
Equipment Calibration: Ensure surveying instruments (total stations, GPS, laser levels) are recently calibrated and have valid certificates.
Material Suitability: For projects where excavated soil will be reused as backfill, collect representative samples before excavation and have them tested for classification, moisture content, and compaction properties in accordance with ASTM D698/D1557.
8.2 Setting Out Verification
Alignment and Levels: Recheck excavation boundaries, depths, and slopes against design tolerances before machine digging begins.
Offset Records: Record and protect offset stakes or pegs to allow re-verification if boundaries are disturbed during excavation.
Double Survey Checks: Have the setting out verified by both the contractor’s and consultant’s survey teams before proceeding.
8.3 In-Progress Excavation Inspections
Depth and Dimension Control: Continuously monitor excavation depth and width using calibrated measuring tools or surveying instruments. Adjust work immediately if deviations are detected.
Slope Stability Monitoring: Inspect excavation faces daily and after any rainfall or vibration event. Record any cracks, bulges, or soil slippage.
Shoring System Inspection: Ensure trench boxes, sheet piles, or soldier pile lagging are installed according to the approved design and that there is no visible deformation.
Layer-by-Layer Monitoring: For large or deep excavations, record progress per layer or section to maintain clear traceability in case of disputes or QA audits.
8.4 Backfilling Quality Control
Material Approval: Only approved fill material, free from organic matter, debris, or oversized rocks, should be used for backfilling.
Layer Thickness: Place fill in layers not exceeding 300 mm loose thickness before compaction.
Compaction Testing: Perform field density tests (FDT) using the sand cone method or nuclear density gauge after each compacted layer. Ensure the achieved density meets project specifications — typically 90–95% of Modified Proctor for structural fills.
Moisture Content Control: Check the moisture content before compaction to ensure it is within the optimum range for the material type.
Defect Rectification: If a layer fails compaction tests, loosen, re-moisturize (or dry), and re-compact before placing additional layers.
8.5 Protection of Excavated Formation
Avoid Damage: Prevent machinery or foot traffic from disturbing the prepared formation surface.
Drainage Maintenance: Ensure water is not allowed to pond on the formation. If rain is forecast, protect with tarpaulins or temporary covers.
Bearing Capacity Testing: For foundation excavations, conduct plate load tests or other specified bearing capacity tests to confirm the soil can safely support the design loads.
8.6 Final Inspection and Approval
As-Built Survey: Conduct a final survey of the excavation to record exact dimensions, depths, and slopes.
Consultant Approval: Notify the supervising consultant in advance for inspection and sign-off before backfilling or commencing the next construction stage.
Photographic Documentation: Capture high-resolution images of key stages for the project quality records and potential dispute resolution.
Record Keeping: Maintain a dedicated quality file containing inspection forms, survey records, compaction test reports, calibration certificates, and approval sheets.
8.7 Non-Conformance and Corrective Actions
Immediate Reporting: If any non-compliance is detected — such as over-excavation, poor compaction, or incorrect slope angles — report to the Site Engineer and Quality Control Manager immediately.
Rectification Plan: Agree on a corrective action plan with the consultant before proceeding.
Follow-Up Inspections: After corrective work, re-test and re-document to confirm compliance before continuing with subsequent works.
9. Environmental Considerations
Excavation works have a direct and sometimes significant impact on the surrounding environment. These impacts can include soil erosion, dust generation, noise, water pollution, habitat disturbance, and improper waste handling. By integrating strong environmental controls into the excavation Method Statement, contractors can comply with environmental regulations, protect the ecosystem, and maintain good relations with the local community. This section outlines detailed measures to mitigate and monitor environmental risks throughout the excavation process.
9.1 Compliance with Environmental Regulations
Regulatory Review: Familiarize the team with local environmental laws, municipal requirements, and any project-specific Environmental Management Plans (EMP).
Permits and Approvals: Secure all required environmental permits before starting, including waste disposal permits, dewatering discharge permits, and tree removal approvals.
Environmental Induction: Provide site-specific environmental awareness training to all workers, emphasizing correct waste disposal, spill prevention, and dust control measures.
9.2 Soil Erosion and Sediment Control
Silt Fences & Sediment Barriers: Install silt fences, sediment traps, or straw bales around excavation areas to prevent soil from washing into storm drains and water bodies.
Temporary Drainage Channels: Create diversion ditches to route stormwater away from open excavations.
Stabilization of Slopes: Where excavations are left open for extended periods, stabilize slopes with geotextile fabric or temporary grassing to reduce erosion.
Sediment Basins: For large-scale sites, build temporary sediment ponds to capture runoff and allow solids to settle before water is discharged.
9.3 Dust Suppression Measures
Water Spraying: Regularly spray water on exposed soil, especially during dry and windy conditions, to minimize airborne dust.
Material Covering: Cover soil stockpiles with tarpaulins or geotextile sheets when not in use.
Speed Limits: Enforce low vehicle speeds on unpaved site roads to reduce dust generation.
Wheel Washing Stations: Install wheel wash facilities at site exits to prevent dust and mud from being carried onto public roads.
9.4 Noise and Vibration Control
Equipment Maintenance: Keep excavation machinery in good working order to minimize noise emissions.
Working Hours Compliance: Restrict noisy activities to approved daytime hours as per local regulations.
Noise Barriers: Use temporary noise barriers or earth berms when excavating near sensitive receptors like schools, hospitals, or residential areas.
Vibration Monitoring: If working close to existing structures, monitor vibrations to ensure they remain within safe limits defined by standards such as BS 7385.
9.5 Water Management and Pollution Prevention
Dewatering Control: Ensure that pumped water from excavations is filtered to remove sediment before discharge.
Preventing Contamination: Never discharge water containing oil, fuel, or chemicals into the environment. Use oil-water separators if needed.
Spill Prevention and Response: Store fuel and lubricants in bunded areas; have spill kits available on-site. Train workers in immediate spill containment and reporting procedures.
Groundwater Protection: Avoid unnecessary lowering of the water table, which can damage nearby vegetation and structures.
9.6 Waste Management
Segregation: Separate excavated materials, recyclables, hazardous waste, and general waste into designated containers.
Licensed Disposal: Dispose of unsuitable material and waste only at approved landfill sites or recycling centers. Keep disposal receipts for records.
Recycling and Reuse: Reuse excavated material as backfill or embankment fill whenever suitable and compliant with specifications.
9.7 Protection of Flora, Fauna, and Cultural Heritage
Vegetation Preservation: Identify and protect trees and plants not marked for removal. Install tree protection fencing as required.
Wildlife Considerations: Avoid disturbing wildlife habitats. If excavation encounters protected species, stop work and notify environmental authorities.
Archaeological Finds: If cultural or historical artifacts are discovered during excavation, stop work in that area, protect the find, and inform the relevant heritage department immediately.
9.8 Monitoring and Reporting
Daily Inspections: Have the Environmental Officer conduct daily checks on dust control, water management, and erosion protection.
Incident Reporting: Record and report any environmental incident, such as spills, uncontrolled runoff, or excessive dust emissions, to the Project Manager and environmental authorities where required.
Record Keeping: Maintain logs of environmental training, inspection checklists, waste disposal receipts, and environmental test results for compliance audits.
10. Deliverables
Deliverables are the formal records and documents generated during and after excavation works to confirm that the activities were executed in accordance with the approved Method Statement, project specifications, and applicable regulations. They serve as evidence for quality compliance, safety adherence, and contractual obligations. These documents also form part of the permanent project record for future reference, maintenance, or dispute resolution.
10.1 Pre-Excavation Deliverables
Approved Method Statement: A copy of the signed and approved excavation method statement, including all referenced drawings and safety procedures.
Risk Assessment & Environmental Plan: Site-specific hazard identification, risk assessment, and environmental management plan approved by the HSE and Environmental Managers.
Survey Setting-Out Records: Verification reports and coordinates of excavation boundaries and levels from the survey team, signed by both contractor and consultant.
Utility Clearance Certificates: Written confirmation from relevant authorities or utility companies that underground services have been located, protected, or diverted as required.
Permits to Work: Excavation permits, dewatering discharge permits, traffic diversion approvals (if applicable), and any other statutory clearances.
10.2 In-Progress Excavation Deliverables
Daily Progress Reports: Detailing work completed, weather conditions, equipment used, manpower deployed, and any incidents or delays.
Inspection Checklists: Signed checklists from the Site Engineer, Quality Control Manager, and HSE Officer covering slope stability, shoring condition, dewatering efficiency, and access safety.
Survey Spot Checks: Intermediate level and alignment surveys confirming excavation progress is within tolerance.
Material Classification Records: Documentation of excavated material types, including laboratory test results for moisture content, gradation, and compaction suitability.
Non-Conformance Reports (NCRs): If any deviation from the approved plan occurs, a record of the issue, corrective action taken, and consultant approval.
10.3 Post-Excavation Deliverables
Final As-Built Survey Drawings: Showing the exact dimensions, depths, slopes, and formation levels achieved. These should be signed off by both the contractor and the consultant.
Compaction Test Reports: Field density test results for all backfilled layers, including the location of each test and achieved compaction percentage compared to specifications.
Bearing Capacity Test Reports: If required for foundation excavations, results from plate load tests or other bearing capacity verification methods.
Waste Disposal Certificates: Receipts and weighbridge slips from approved landfill or recycling facilities showing the quantity and type of disposed material.
Photographic Records: High-resolution photographs showing each stage of excavation, shoring installation, dewatering operations, backfilling, and final grading. These should be labeled with dates and locations.
Environmental Compliance Reports: Logs and evidence of dust suppression, sediment control measures, spill prevention, and waste segregation.
Final Inspection & Approval Certificates: Written confirmation from the supervising consultant or client representative that the excavation works have been completed to specification and are approved for the next stage of construction.
10.4 Submission and Archiving Protocols
Electronic and Hard Copies: All deliverables should be compiled in both electronic format (PDF/DWG/Excel) and hard copy for submission.
Filing and Indexing: Organize documents with a clear index and numbering system so they can be easily referenced in future audits.
Retention Period: Store all deliverables in the project archive for the duration required by the contract or local regulations — often a minimum of 10 years.
Conclusion
A detailed Method Statement for excavation is essential for safe, compliant, and efficient execution of construction works. By following this procedure, contractors can ensure that excavation is carried out within safety limits, meets quality requirements, and minimizes environmental impact. Proper planning, supervision, and adherence to the outlined steps can prevent costly delays, structural failures, and safety incidents, ultimately leading to a successful project outcome.
