Site Clearing AHA (Activity Hazard Analysis / Job Hazard Analysis)

Updated 2026-06-23

A Site Clearing AHA (Activity Hazard Analysis / Job Hazard Analysis) heads the clearing operations — the general clearing of a site to prepare it for construction, removing vegetation, trees, brush, debris, and surface obstructions. It's often the first work on a site, and it carries real hazards: falling trees and limbs, chainsaws and clearing equipment, debris, and the unknowns of ground not yet worked.

Why site clearing needs its own AHA

Site clearing is the general clearing of a site — removing the vegetation (trees, brush, undergrowth), debris, and surface obstructions so the site can be developed. It's typically one of the first operations, preparing raw ground for the earthwork and construction to follow. Its hazards come from the clearing work: tree and vegetation removal (falling trees and limbs, chainsaw work, and the equipment used), the clearing equipment (dozers, mulchers, grinders — struck-by hazards), the debris (handling and disposing of the cleared material), and the site itself (an uncleared site's terrain, existing structures, and possible unknowns — buried objects, old utilities, or hazards not yet identified). So the plan centers on the site clearing scope, the clearing hazards, and the earthwork context, with the specific clearing operations (clearing and grubbing, selective clearing, tree removal) detailed in their own docs.

Three concerns anchor the clearing work: the site clearing scope, the clearing hazards, and the earthwork context.

Breaking site clearing into steps

• Confirm the clearing scope, limits, and what to preserve from the design
• Survey the site for hazards (structures, utilities, terrain, unknowns)
• Remove the trees and vegetation (falling, cutting)
• Clear the brush, debris, and surface obstructions
• Handle and dispose of the cleared material
• Prepare the cleared site for the following earthwork

The hazards step by step

The tree and vegetation removal hazards

A major clearing hazard is removing trees and vegetation — bringing falling-tree/limb, chainsaw, and equipment hazards. Felling trees is hazardous work: a tree being felled can fall unpredictably (if not properly cut and directed), and limbs can fall (widow-makers), so tree felling requires skilled technique and keeping people clear of the fall zone. Chainsaws (used for cutting) are dangerous tools (cuts, kickback). And clearing equipment removes vegetation (dozers pushing, mulchers/grinders processing) with struck-by hazards. So the tree and vegetation removal — falling trees and limbs, chainsaw hazards, and the equipment — is a leading clearing hazard, requiring skilled tree work, clear fall zones, and safe equipment operation. So this removal work is where much of the clearing danger lies.

The clearing equipment and debris

Site clearing uses heavy equipment and generates debris — bringing equipment struck-by hazards and material handling. Clearing equipment (dozers pushing over and piling vegetation, mulchers and grinders processing material, loaders and trucks hauling) operates on the site, so workers near it face struck-by and caught hazards (managed by separating workers from the equipment). And the clearing generates debris (felled trees, brush, stumps, and other material) that's handled, piled, processed, and disposed of (chipped, hauled, or otherwise managed) — a material-handling effort. So the clearing equipment (struck-by) and the debris (handling, disposal) are significant parts of the clearing hazards. So safe equipment operation and debris handling are central.

The uncleared-site unknowns and terrain

An uncleared site poses hazards from what isn't yet known or visible — so surveying and caution matter. Before clearing, the site may have existing structures (to be aware of or remove), old or unknown utilities (that could be present), buried objects, uneven or difficult terrain (obscured by vegetation), and other unknowns (old wells, tanks, or hazards). So the site is surveyed and assessed before and during clearing (identifying hazards, utilities, and features), and the work proceeds with awareness that an uncleared site can hold surprises. So the uncleared-site unknowns and terrain are a distinctive clearing hazard — the ground isn't yet understood, so caution and assessment are needed. So surveying the site is an important early step.

The earthwork context, standards, and fundamentals

The earthwork context (clearing is the start of earthwork, and equipment operates on the site), the applicable standards (and the erosion/sediment control that follows clearing, since cleared ground erodes), the utility awareness, and the general fundamentals apply. The specific clearing operations are in their own docs.

A simple Site Clearing AHA structure

Where the clearing hazards define the work

Site clearing is defined by the general clearing of a site — so its hazards are the tree and vegetation removal (falling trees/limbs, chainsaws), the clearing equipment (struck-by) and debris (handling), and the uncleared-site unknowns (surveying for hazards and utilities). So the plan centers on those clearing hazards, in the earthwork context. The clearing work — removing vegetation and obstructions safely from ground not yet understood — is what defines site clearing, with the specific operations detailed separately.

From the field: what actually goes wrong

The site clearing incidents are the clearing hazards: struck-by-falling-tree or limb during felling (a serious, often fatal hazard), chainsaw injuries, struck-by-equipment incidents, and encounters with site unknowns (striking an unidentified utility, or hazards on an uncleared site). The lessons: fell trees skillfully with clear fall zones and safe chainsaw work; separate workers from the clearing equipment; survey the site for hazards and utilities before clearing; and handle the debris and manage the cleared ground (erosion). The clearing hazards — trees, equipment, unknowns — are the focus, detailed further in the specific docs.

The bottom line

A Site Clearing AHA heads the clearing operations — the general clearing of a site (vegetation, trees, brush, debris, obstructions) — so its hazards are the tree/vegetation removal (falling trees and limbs, chainsaws), the clearing equipment (struck-by) and debris, and the uncleared-site unknowns (surveying for utilities and hazards). Fell trees safely, separate workers from equipment, survey the site, and manage the debris and cleared ground. The clearing and grubbing, selective clearing, and tree removal AHAs detail the specific operations on this foundation.

Frequently asked questions

What does site clearing involve?

Site clearing involves removing the vegetation, debris, and surface obstructions from a site to prepare it for construction — typically one of the first operations on a project. It includes removing trees (felling and clearing), brush and undergrowth, other vegetation, debris, and surface obstructions (old surface structures, rubble, and features that need to be cleared) — leaving the site cleared and ready for the earthwork and construction to follow. It may be a complete clearing of the site (removing all vegetation) or, in some cases, selective (preserving specified trees and features — covered in the selective clearing doc). So it's the operation that clears raw or vegetated ground to prepare it for development. This AHA heads the clearing operations, framing the general site clearing and its hazards (tree removal, equipment, debris, site unknowns), while the specific clearing operations — clearing and grubbing (which includes removing roots), selective clearing (preserving some), and tree/shrub removal — have their own detailed docs. So it's the general site-clearing work that begins site preparation, with related docs for the specific clearing operations.

Why is tree removal such a significant hazard?

Because felling trees is inherently dangerous work — a tree or its limbs can fall unpredictably with great force, and the tools involved (chainsaws) are hazardous — so tree removal is one of the most serious clearing hazards. When a tree is felled, it must fall in a controlled direction, which requires skilled cutting technique (the right cuts to direct the fall); if done improperly, a tree can fall in an unintended direction, or "kick back," or barber-chair (split dangerously) — endangering anyone in the area. And even standing or partially cut trees can drop limbs ("widow-makers" — dead or broken limbs that fall unexpectedly), a serious overhead hazard. Chainsaws, the primary cutting tool, are dangerous (severe cuts, kickback injuries). So tree removal requires skilled workers, proper felling technique, keeping people clear of the fall zone and out from under trees being worked, and chainsaw safety. Struck-by-falling-tree or limb incidents are frequently fatal. So tree removal is a significant, potentially fatal clearing hazard, requiring skill and strict fall-zone control — which is why it (and selective tree/shrub removal) is treated carefully, with a dedicated doc for the tree/shrub removal specifics.

What unknowns does an uncleared site pose?

An uncleared site can hold hazards that aren't visible or known until the clearing exposes them — so it must be surveyed and approached with caution. Before clearing, vegetation and surface conditions can obscure what's there, so the site may hold: existing structures (buildings, foundations, or remnants to be aware of or removed), old or unknown utilities (buried or abandoned lines — electric, gas, water — that could be present and struck during clearing or subsequent earthwork), buried objects (debris, tanks, wells, or other buried items), difficult or uneven terrain (hidden under vegetation — slopes, holes, water), and possible environmental hazards (contamination, hazardous materials on a previously used site). So an uncleared site is ground not yet understood, which can produce surprises during clearing. So the site is surveyed and assessed before and during clearing (investigating the site, checking for utilities, identifying structures and hazards), and the work proceeds with awareness of possible unknowns. So the uncleared-site unknowns are a distinctive early hazard — the site must be investigated so the clearing (and subsequent earthwork) isn't caught off guard by what the ground holds. So surveying and caution are essential at the clearing stage.

How does this head relate to the specific clearing docs?

This head frames the general site clearing, while the specific clearing operations have their own docs. The clearing and grubbing doc covers clearing that includes grubbing (removing roots and stumps below grade, not just surface vegetation). The selective clearing doc covers clearing that preserves specified vegetation (selectively removing while protecting designated trees and features). The selective tree and shrub removal and trimming doc covers the specific tree and shrub work (removal and trimming). So this head establishes the general site-clearing framing (the scope and hazards), and the specific docs cover each clearing operation's particulars (grubbing roots, selective preservation, tree/shrub specifics). So use this head for the general site clearing and its hazards, and the specific docs for clearing and grubbing, selective clearing, or tree/shrub removal. Together they cover the clearing operations, from the general framing down to the specific types. So it heads the clearing family, with the details in the specific docs. The clearing hazards framed here (trees, equipment, debris, unknowns) apply across the specific operations.

Related AHAs and JHAs

• Earthwork AHA — the earthwork division fundamentals
• Clearing and Grubbing AHA — clearing including root/stump removal
• Selective Clearing AHA — clearing that preserves specified vegetation
• 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.