Excavation Scope of Work: Template and Checklist for GCs and Estimators

Excavation is one of the highest-risk scopes on any ground-up commercial project. Unforeseen soil conditions, utility conflicts, dewatering complications, and undefined haul and fill responsibilities generate more budget overruns in civil and earthwork than almost any other trade. A well-written excavation scope of work defines soil classification responsibilities, shoring requirements, compaction standards, and utility protection obligations before the first machine hits the ground — preventing costly disputes and schedule delays. This template covers the critical line items every PM and estimator should include.

Excavation scopes must be specific about what type of excavation is included, how spoil is handled, and what the final subgrade conditions must be.

Site Clearing and Topsoil Stripping

• Site clearing: Define limits of clearing and grubbing — all trees, stumps, brush, and vegetation within the grading limits. Specify whether stumps are to be removed or ground in place, and whether root systems must be extracted to a minimum depth. Root extraction to 36" minimum is typically required under structural slabs.
• Topsoil stripping: Strip and stockpile topsoil to the depth defined by the geotechnical report (typically 150–300 mm / 6–12"). Define the stockpile location, maximum height, and erosion protection requirements. Specify whether topsoil is to be re-spread on site (landscaping) or hauled off.
• Demolition debris: If the site contains existing foundations, buried utilities, or underground storage tanks (USTs), define these as separate scope items. UST removal is a regulated activity requiring environmental assessment — do not bundle this into a general excavation scope.

Mass Excavation and Structural Excavation

• Mass excavation: Define the limits horizontally and vertically (bench marks, existing grades, and design grades). Specify allowable over-excavation tolerances — typically ±0.05m of design grade for mass earthworks.
• Structural excavation: Footing pads, pile caps, grade beams, elevator pits, and sump pits require neat-cut excavation to exact dimensions per structural drawings. Define the required subgrade bearing surface inspection (geotechnical engineer sign-off required before concrete placement).
• Rock excavation: If rock is encountered, define the method of removal — blasting (requires permit, pre-blast survey, vibration monitoring) or mechanical (hoe-ramming, hydraulic splitter). Blasting near existing structures, utilities, and property lines requires a blast plan and vibration monitoring program. Include a unit rate for rock as an optional bid item.

Soil Classification and Slope Requirements

• Soil classification per OSHA 29 CFR 1926 Subpart P (Type A, B, or C) determines allowable slope ratios for unshored cuts. Require the sub to have a competent person on site at all times per OSHA requirements.
• For cuts exceeding OSHA maximum depths (typically 20 ft without shoring for Type A soil, 15 ft for Type B, and 12 ft for Type C), a licensed professional engineer must design the shoring system.
• Benching and sloping plans must be submitted before excavation begins in any deep cut. Define the review and approval process for these plans.

Shoring and Underpinning

• Soldier pile and lagging: H-pile driven or drilled at defined spacing, with timber lagging boards installed as excavation proceeds. Specify pile size, spacing, and lagging thickness. Soldier pile and lagging is the most common shoring system for commercial urban excavations.
• Sheet pile: Interlocking steel sheet pile (PZ sections) for watertight excavation in high groundwater conditions. Specify pile section, embedment depth, and whether piles are to be extracted or abandoned in place.
• Soil nail walls: For permanent or temporary retention. Nail length, diameter, grout, and facing design must be by a licensed geotechnical engineer. Include monitoring program.
• All shoring designs must be stamped by a licensed professional engineer and submitted for review before installation begins.

Dewatering

• Define the dewatering method — wellpoints, deep wells, sump pumping — based on the geotechnical report's groundwater levels.
• Discharge of dewatering effluent requires a municipal permit in most jurisdictions. Identify who obtains the permit and who is responsible for treatment if sediment or contaminants are present.
• Dewatering must maintain the excavation in a stable, workable condition for the duration of earthworks. Define the acceptable groundwater level below subgrade for footing construction.

Tip for PMs: The most common excavation scope gap is who pays for unforeseen conditions — rock, contaminated soil, underground utilities not shown on survey. Define a unit rate for rock ($/m³ or $/CY) and a provisional sum for contaminated soil disposal in your contract. Do not leave these as TBD.

The excavation package must align with the geotechnical report, survey, and civil drawings. Do not issue an excavation RFP before these documents are available.

Required Pre-Construction Documents

• Geotechnical investigation report — boring logs, soil classifications, bearing capacity recommendations, groundwater levels, frost depth, and site-specific recommendations for shoring and dewatering
• Topographic survey (existing grades, property lines, existing utility locations)
• Utility locates: contact the applicable utility authority (Ontario One Call, 811, or local authority) a minimum of 5 business days before excavation. Require a ticket number and locate marks as a pre-condition for mobilization.
• Erosion and sediment control (ESC) plan compliance — silt fence, catch basin protection, construction entrance stabilization
• IFC civil and structural drawings showing design grades, footing layouts, and utility trench routes

Fill Material and Compaction Standards

• Structural fill: Imported granular material (Granular A, Granular B Type I/II, or equivalent per local specification) for backfill under slabs-on-grade, footings, and road base. Specify gradation and maximum particle size per OPSS, ASTM, or local standard.
• Compaction standard: 95% Standard Proctor (ASTM D698) minimum for most structural fill applications; 98% Modified Proctor (ASTM D1557) under slabs, footings, and pavement. Define lift thickness — typically 150–200 mm (6–8") compacted lifts for most equipment.
• Compaction testing: Specify the testing frequency (e.g., one nuclear density test per 250 m² per lift, or per structural engineer's requirement) and who pays for testing. Failed tests require re-compaction and re-testing at the sub's cost.
• Native material re-use as structural fill must be confirmed by the geotechnical engineer. Expansive soils, organics, and frost-susceptible material are generally not acceptable as structural fill.

Best Practices from Leading GCs

• Require the excavation sub to submit a daily earthwork log showing cut and fill volumes, truck counts, and dewatering volumes. This data is essential for resolving quantity disputes and tracking progress against the earthwork balance.
• Hold a pre-excavation meeting with the excavation sub, geotechnical engineer, and structural engineer before mobilization. Review the shoring plan, dewatering plan, and utility protection zones together.
• Define clear haul routes on-site and a designated truck staging area to prevent conflicts with other trades during peak earthwork operations.

Excavation is typically the first major trade on site, but it sequences with survey, utilities, and the geotechnical engineer throughout the project.

Utility Coordination

• All underground utilities (watermain, storm sewer, sanitary sewer, gas, hydro, telecom) must be located and marked before excavation begins. Within the tolerance zone (typically 1m of the locate), hand digging is required.
• Protect existing utilities that remain in service during excavation. Define protection methods for utilities passing through the excavation footprint (thrust blocks, pipe bridging, temporary supports).
• Utility trench excavation for new services (watermain, storm, sanitary) may be part of the excavation scope or a separate utility scope — define this clearly to avoid double-counting or gaps.

Geotechnical and Structural Inspection Sequence

• Geotechnical engineer sign-off required at the following milestones: (a) subgrade bearing surface prior to footing formwork, (b) granular fill lifts at compaction test frequency, (c) shoring performance monitoring review.
• Surveyor required for grade stake control at mass excavation completion and for footing layout prior to structural excavation.
• Structural engineer must review and approve the shoring design before any excavation exceeding OSHA safe slope limits.

Pre-Excavation Coordination Checklist

• Geotechnical report reviewed and site-specific requirements incorporated into scope
• Utility locate ticket obtained — minimum 5 business days before mobilization
• Topographic survey complete and confirmed against design drawings
• Erosion and sediment control measures installed before any grading begins
• Shoring design submitted, reviewed, and approved (if applicable)
• Dewatering permit obtained and discharge point confirmed
• Haul routes and truck staging areas defined
• Pre-excavation meeting held with geotech, structural, and excavation sub

Tip for Estimators: When reviewing an excavation sub's bid, check whether cut-to-fill balance is addressed. A bid that includes only gross cut volume without addressing import fill for over-excavation, subgrade replacement of unsuitable material, or compaction lift thickness requirements is underestimating the total earthwork cost.