Clearing and Grubbing AHA (Activity Hazard Analysis / Job Hazard Analysis)
Updated 2026-06-23
A Clearing and Grubbing AHA (Activity Hazard Analysis / Job Hazard Analysis) plans clearing that includes grubbing — removing not just the surface vegetation but the roots, stumps, and below-grade organic material. Grubbing goes below the surface to pull out stumps and root balls, because organic material left in the subgrade would decompose and cause settlement.
Why clearing and grubbing needs its own AHA
Clearing removes the surface vegetation; grubbing goes further — removing the roots, stumps, and below-grade organic material that clearing leaves behind. So clearing and grubbing means both the surface clearing (removing trees, brush, and vegetation) and the grubbing (digging out and pulling the stumps and root balls, and removing the below-grade organic matter) — so the site is cleared of vegetation above and below grade. The reason for grubbing is a subgrade-quality one: organic material left in the ground (roots, stumps, buried organics) decomposes over time and causes settlement — so it's removed to provide a stable subgrade for what's built on it. And grubbing adds stump-pulling and excavation hazards to the clearing hazards. So the plan centers on the grubbing (below-grade root and stump removal), the reason for it (a stable subgrade), and the clearing plus stump-removal hazards.
Three concerns carry the plan: the clearing and grubbing scope, the grubbing and root/stump removal, and the clearing plus stump-removal hazards.
Breaking clearing and grubbing into steps
- Confirm the clearing and grubbing scope and depth from the design
- Clear the surface vegetation (trees, brush)
- Grub out the stumps and root balls (digging, pulling)
- Remove the below-grade organic material from the subgrade
- Backfill and manage the resulting holes/depressions
- Handle and dispose of the cleared and grubbed material
The hazards step by step
The grubbing and root/stump removal
The distinctive work is grubbing — removing the roots, stumps, and below-grade organic material. After the surface vegetation is cleared, grubbing digs out and pulls the stumps and root balls (which extend below grade) and removes the below-grade organic material — so it's a below-grade removal operation. Stumps and root balls are pulled or dug out (typically with equipment — excavators or dozers pulling and digging), which is a substantial effort (large root systems resist removal, and pulling stumps has hazards — the stump breaking free suddenly, equipment strain). And the removal leaves holes and depressions (where stumps and root balls were) that are backfilled and managed. So the grubbing — pulling stumps, digging out root balls, removing below-grade organics — is the operation that distinguishes clearing and grubbing from surface clearing, going below grade to remove what clearing leaves. So the below-grade root and stump removal is the defining work.
The reason for grubbing: a stable subgrade
Grubbing exists for a subgrade-quality reason — organic material left in the ground causes settlement, so it's removed. If roots, stumps, and organic matter were left in the subgrade, they would decompose over time (organic material decays), creating voids and causing the ground above to settle — a problem for anything built on it (settlement of fills, foundations, slabs, and pavements). So grubbing removes the organic material to provide a stable, non-organic subgrade that won't settle from decomposition. So the reason for grubbing is foundational: a stable subgrade requires removing the organic material, which is why grubbing goes below the surface. So this subgrade-quality purpose is why grubbing is done — it's not just tidiness, but preventing future settlement. So the removal of organics for a stable subgrade is the point.
The clearing plus stump-removal hazards
Clearing and grubbing carries the clearing hazards plus the stump-removal/excavation hazards. The clearing hazards (from the surface clearing) apply: tree and vegetation removal (falling trees/limbs, chainsaws), clearing equipment (struck-by), and debris. The grubbing adds: stump-pulling hazards (a stump or root breaking free suddenly under equipment force, the equipment strain and instability pulling stumps), the excavation/digging hazards (digging out root balls, the resulting holes — a fall/trip hazard, and where deep, excavation concerns), and heavy equipment doing the grubbing (struck-by). So the hazards combine the clearing hazards with the stump-pulling and excavation hazards of grubbing. So safe clearing plus safe stump removal (controlled pulling, managing the holes, equipment safety) are needed. So the combined clearing-and- grubbing hazards apply.
The earthwork context, standards, and fundamentals
The earthwork context (grubbing is earthmoving), the applicable standards, the erosion control (grubbed ground is disturbed and erodes), the utility awareness (grubbing digs below grade, near possible utilities), and the general fundamentals apply.
A simple Clearing and Grubbing AHA structure
| Step | Hazard/Concern | Control | Standard |
|---|---|---|---|
| Clear surface vegetation | Falling trees/limbs; chainsaw | Skilled felling; clear fall zone; chainsaw safety | OSHA 1910.266 |
| Grub stumps/roots | Stump breaking free; equipment | Controlled pulling; safe equipment operation | OSHA 1926.601 |
| Remove below-grade organics | Organics left (settlement) | Remove organic material for stable subgrade | geotech spec |
| Manage resulting holes | Falls/trips; instability | Backfill/manage holes; excavation care where deep | OSHA Subpart P |
| Dispose material | Handling; disposal | Safe debris/stump handling and disposal | general |
Where the grubbing defines the work
Clearing and grubbing is defined by the grubbing — removing the roots, stumps, and below-grade organic material that surface clearing leaves — for the subgrade-quality reason that organic material would decompose and cause settlement. So the plan centers on the below-grade root and stump removal (pulling stumps, digging root balls, removing organics) and its hazards (stump-pulling, excavation), on top of the clearing hazards. The grubbing — going below grade for a stable subgrade — is what distinguishes this from surface clearing.
From the field: what actually goes wrong
The clearing and grubbing incidents combine the clearing hazards (falling trees, chainsaws, equipment struck-by) with the grubbing hazards: a stump or root breaking free suddenly under equipment force (a struck-by or equipment-instability hazard), and the holes left by stump removal (falls/trips). And a subgrade-quality failure: organic material left in the subgrade later decomposing and causing settlement. The lessons: apply the clearing safety (skilled felling, fall zones, equipment separation); grub the stumps and roots with controlled pulling and safe equipment; remove the organics for a stable subgrade; and manage the resulting holes. The grubbing removes what clearing leaves, for a stable subgrade.
The bottom line
A Clearing and Grubbing AHA covers clearing plus grubbing — removing not just surface vegetation but the roots, stumps, and below-grade organic material — because organics left in the subgrade decompose and cause settlement, so grubbing provides a stable subgrade. It carries the clearing hazards (falling trees, chainsaws, equipment) plus the stump-removal hazards (stumps breaking free, resulting holes). Grub out the stumps and organics safely for a stable subgrade. The grubbing defines the work.
Frequently asked questions
What is grubbing, and how does it differ from clearing?
Grubbing is the removal of roots, stumps, and below-grade organic material — going below the surface — as distinct from clearing, which removes the surface vegetation. Clearing removes what's above the ground: trees (felled), brush, and vegetation. But this leaves behind the below-grade parts — the stumps and root systems (which extend into the ground) and other buried organic material. Grubbing removes these: digging out and pulling the stumps and root balls, and removing the below-grade organic matter, so the ground is cleared below the surface as well as above. So clearing and grubbing together fully clear a site of vegetation, above and below grade — clearing handling the surface, grubbing handling the below-grade roots and stumps. The reason grubbing is added is a subgrade-quality one: organic material left in the ground decomposes over time and causes settlement, so it's removed to provide a stable subgrade. So grubbing is the below-grade complement to surface clearing, distinguished by removing the roots, stumps, and organics that clearing leaves — which is why this operation is "clearing and grubbing" rather than just clearing.
Why is grubbing necessary for a stable subgrade?
Because organic material left in the subgrade decomposes over time, creating voids and causing settlement — so grubbing removes it to provide a stable, non-settling subgrade. Roots, stumps, and buried organic matter are biological material that decays over time (organic decomposition). If left in the ground beneath a construction area, this organic material would gradually decompose, creating voids (as the material breaks down and loses volume) and allowing the ground above to settle into those voids — causing settlement of whatever is built on it (fills, foundations, slabs, pavements, which could crack, sink, or become uneven as the underlying organics decay). So to prevent this future settlement, the organic material is removed by grubbing — leaving a subgrade of stable, non-organic soil that won't decompose and settle. So grubbing is necessary for subgrade stability: it removes the organic material that would otherwise cause delayed settlement problems. This is why grubbing is a standard part of site preparation where a stable subgrade is needed — it's not just about clearing vegetation, but about ensuring the ground beneath the construction won't settle due to decomposing organics. So the stable subgrade is the fundamental reason for grubbing.
What are the hazards specific to grubbing?
Grubbing adds stump-pulling and excavation hazards to the clearing hazards. Stump-pulling: removing stumps and root balls typically involves equipment (excavators, dozers) pulling and digging them out, which has specific hazards — a stump or large root can break free suddenly under the pulling force (releasing stored energy, potentially causing the equipment to lurch or the stump to move unexpectedly, a struck-by or equipment-instability hazard), and the equipment is strained doing heavy pulling. Excavation/holes: grubbing digs below grade to remove root balls, leaving holes and depressions where stumps and roots were — these are trip and fall hazards, and where deep, excavation concerns; they're backfilled and managed. And grubbing digs below grade, so there's utility awareness (below-grade digging near possible utilities). So on top of the clearing hazards (falling trees, chainsaws, equipment struck-by), grubbing adds the stump-pulling hazards (sudden release, equipment strain) and the resulting holes. So safe grubbing requires controlled stump pulling (managing the sudden-release hazard), safe equipment operation, and managing the holes left behind. So the grubbing-specific hazards center on the below-grade stump and root removal.
How does clearing and grubbing relate to the other clearing operations?
Clearing and grubbing is the clearing operation that includes below-grade root/stump removal, among the clearing family. The site clearing head covers the general site clearing. This clearing and grubbing doc covers clearing that includes grubbing (the below-grade removal for a stable subgrade). The selective clearing doc covers clearing that preserves specified vegetation (removing some while protecting designated trees/features). The selective tree and shrub removal and trimming doc covers the specific tree/shrub work. So clearing and grubbing is distinguished by the grubbing (going below grade), whereas selective clearing is distinguished by the selectivity (preserving some). A given project's clearing might be full clearing and grubbing (remove everything, above and below grade), selective (preserve some), or focused on specific tree/shrub work. So use this doc for clearing that includes grubbing (the below-grade root/stump removal for a stable subgrade), the selective clearing doc for clearing that preserves vegetation, and the tree/shrub doc for the specific tree work. Together they cover the clearing operations, with this doc's distinction being the grubbing. So it's the below-grade-inclusive clearing, for a stable subgrade.
Related AHAs and JHAs
- Site Clearing AHA — the general site clearing head
- Selective Clearing AHA — clearing that preserves specified vegetation
- Earthwork AHA — the earthwork division fundamentals
- Site Clearing and Grubbing JHA — the clearing-and-grubbing fundamentals
Written by Mustafa Tok, CSP, ASP, CHST — OSHA Authorized Outreach Trainer with 14+ years of international construction safety experience across federal, heavy civil, and industrial projects.