Excavation and Trenching: Competent Person
This course covers what a competent person for excavations needs to know under Cal/OSHA's Construction Safety Orders: the job itself, permits and 811, soil classification, sloping, shoring and shields, access, water and air, and daily inspections. It also covers the California rules that go beyond federal OSHA.
There are 8 short lessons with animations and videos. Each lesson ends with a check question you must answer correctly to move on. The final quiz has 15 questions. You need 12 correct (80%) to pass, and you can retake it as many times as you need.
For employers
Who it's for
Employees you plan to designate as competent persons for excavations, and foremen and superintendents who run trench work.
What it covers
Title 8 §1504 (competent person definition), §341 (permits), and Article 6: §1540, §1541, §1541.1 and Appendices A to F. It also covers Government Code §4216 to 4216.9 (811) and Labor Code §6705 (public works shoring plans). See the lesson map below.
What it doesn't do
Neither Cal/OSHA nor federal OSHA sets a course length or certificate for a competent person. Section 1504 defines the role by ability and authority, and you designate the person. Before you do, check the field skills an online course can't test: visual and manual soil tests on real samples, reading the tabulated data for the shields and shoring you use, and walking a daily inspection. The printable record has lines for that field check and for the designation.
What you still provide
- The Cal/OSHA excavation permit (annual or project) and new-site notifications.
- 811 tickets and your utility locating procedures.
- Manufacturer's or other tabulated data for your protective systems, kept on site while the system is built.
- Air monitoring equipment, rescue equipment and your emergency plan.
- Site-specific procedures. Each lesson has an "At your worksite" box listing what to cover in a tailgate or in writing.
- On public works contracts over $25,000 with trenches 5 feet or deeper, the detailed shoring or sloping plan required by Labor Code §6705.
Results
Set your company name, results email and contact in the CONFIG section near the top of the code in this file. If no results email is set, the worker types one in. Results arrive only when the worker presses Send. The answer key is in the code, so don't post the file anywhere you don't want it read.
Minimum time
The final quiz opens when the worker finishes the lessons. A passing score is recorded only after 30 minutes have passed since the worker started the course — if they pass the questions sooner, the pass is held until the 30-minute mark. The record shows time from start to finish. The minimum is set by minMinutesBeforeQuiz in CONFIG.
Videos
The cave-in video and the CPWR video play from YouTube, and the two OSHA videos open on osha.gov, so they need an internet connection. The animations and everything else work offline.
Lesson map
| Lesson | Title 8 and other rules |
|---|---|
| 1. The competent person's job | §1504; §1541(c), (h), (k); §1541.1(a), (d)(3); App. A (c); App. B (c)(3) |
| 2. Permits and underground utilities | §341; §1541(a), (b); Gov. Code §4216.2, §4216.4; Lab. Code §6705 |
| 3. Soil classification | §1541.1 App. A |
| 4. Sloping and benching | §1541.1(b), (f); App. B; App. F |
| 5. Shoring and shields | §1541.1(c), (d), (e), (g), (h); App. C, D, E |
| 6. Access, spoils, equipment and traffic | §1541(c), (d), (e), (f), (j), (l) |
| 7. Water, air and nearby structures | §1541(g), (h), (i) |
| 8. Daily inspections and stopping work | §1541(k); App. B (b); §342 |
Built to the Title 8 text as published by DIR (October 2026). Section 1541 was last amended in 2012 and §1541.1 in 2011. Government Code §4216.2 and §4216.4 reflect SB 778, effective January 1, 2025.
1. The competent person's job
Trench cave-ins happen with little warning. OSHA notes that one cubic yard of soil can weigh about as much as a car, close to 3,000 pounds. A worker caught in a cave-in can be crushed or suffocated within minutes. The competent person is the one on site whose job is to see the hazard coming and stop the work before that happens.
What the rule says
"Competent Person. One who is capable of identifying existing and predictable hazards in the surroundings or working conditions which are unsanitary, hazardous, or dangerous to employees, and who has authorization to take prompt corrective measures to eliminate them."
You need both parts:
- Knowledge. You can recognize the hazards, including the ones that are coming: rain on the way, a compactor starting up, a spoil pile growing at the edge.
- Authority. Your employer has given you the power to fix the problem or stop the work right away, without waiting for someone else's approval.
What Article 6 makes the competent person do
| Duty | Title 8 |
|---|---|
| Classify each soil deposit using at least one visual and one manual test | App. A (c)(1), (2) |
| Reclassify the soil when conditions change | App. A (c)(5) |
| Examine the ground in excavations under 5 feet and decide whether cave-in protection is needed | §1541.1(a)(1)(B) |
| Inspect the excavation, adjacent areas and protective systems daily: before work, as needed, and after rain or other hazard-increasing events | §1541(k)(1) |
| Remove workers from a hazardous area until it is made safe | §1541(k)(2) |
| Design structural ramps used only by workers | §1541(c)(1)(A) |
| Monitor water removal equipment, and inspect after heavy-rain runoff | §1541(h)(2), (3) |
| Decide how much to flatten a slope for surcharge loads | App. B (c)(3)(C) |
| Examine damaged shoring or shield parts before they are used again | §1541.1(d)(3) |
At your worksite
- Who is the designated competent person for each crew and shift?
- How do you stop work on this site, and who do you notify?
- Who covers for you when you leave the site?
2. Before you dig: permits and underground utilities
Most of the planning happens before the first bucket. Two California requirements come first: the Cal/OSHA permit and the 811 call.
CACal/OSHA excavation permit
- A permit is required to build trenches or excavations 5 feet or deeper that any person is required to enter. Entering any part of it once it reaches 5 feet counts. §341(d)(5)
- Employers hold a project permit (named sites) or an annual permit. Annual permit holders must notify Cal/OSHA each time they start permit-required work at a new site. §341(c)(2)
- Exceptions include emergency repair of underground facilities, excavations no one will enter, graves, swimming pools, government agencies, and utilities regulated by the PUC. §341(e)
CAPublic works: on contracts over $25,000 with trenches 5 feet or deeper, Labor Code §6705 requires a detailed shoring, bracing or sloping plan before excavation starts.
CACall 811 first
- Mark the dig area in white (delineate) before you call. Gov. Code §4216.2(a)
- Notify 811 (USA North 811 or DigAlert) at least 2 working days and no more than 14 calendar days before digging. The day you call does not count. §4216.2(b)
- Don't dig until every operator on the ticket has responded and any required onsite meeting is done. Within 10 feet of a high priority line, the operator sets up an onsite meeting before work starts. High priority lines are high-pressure gas over 60 psig, petroleum, pressurized sewage, cables of 60,000 volts or more, and hazardous materials pipelines. §1541(b)(1)
- Tickets are good for 28 days. Renew by the end of the 28th day. If a ticket expires while work is ongoing, stop digging and get a new one. §4216.2(e), (i)
- Inside the tolerance zone, 24 inches on each side of the marks, find the line with hand tools before using power equipment. Vacuum excavation is allowed only when you told 811 you'd use it and the operator agreed. §4216.4
- While the excavation is open, protect, support or remove exposed lines. §1541(b)(4)
If a line is hit
- Report any damage, even a nick, dent, gouge or scraped coating, to the line's operator right away. §1541(b)(5)
- If gas or a hazardous liquid is escaping, or lives are at risk: get people away, call 911, then the operator.
Also check the surface. Anything that could fall or shift onto workers, such as poles, walls, slabs or trees, must be removed or supported. §1541(a)
At your worksite
- Who calls in tickets and tracks when they expire?
- Where is the Cal/OSHA permit kept, and who notifies Cal/OSHA of a new site?
- Which lines on this job are high priority, and when is the onsite meeting?
3. Soil classification
Soil type decides how steep you can slope and which shoring or shield data you can use. Each deposit is classified as stable rock, Type A, Type B or Type C, from most to least stable. The competent person makes the call using at least one visual test and at least one manual test. App. A (c)(2)
| Class | Strength (unconfined compressive) | Includes |
|---|---|---|
| Stable rock | n/a | Natural solid mineral matter that stays intact with vertical sides while exposed |
| Type A | Cohesive, 1.5 tsf or more | Clay, silty clay, sandy clay, clay loam. Cemented soils such as caliche and hardpan. |
| Type B | Cohesive, more than 0.5 and less than 1.5 tsf | Angular gravel, silt, silt loam, sandy loam. Previously disturbed soil (unless it would be Type C). Type A-strength soil that is fissured or subject to vibration. Dry rock that is not stable. |
| Type C | Cohesive, 0.5 tsf or less | Gravel, sand, loamy sand. Submerged soil or soil with water freely seeping. Submerged rock that is not stable. Layers dipping into the excavation at 4H:1V or steeper. |
Soil is never Type A if it is:
- Fissured (tension cracks, or chunks spalling off a vertical face)
- Subject to vibration from heavy traffic, pile driving or similar
- Previously disturbed (old backfill, utility trenches)
- Part of a layered system with layers dipping into the excavation at 4H:1V or steeper
- Affected by anything else that makes it less stable
Visual tests
- Watch the spoil as it comes out. Clumps mean cohesive. Soil that breaks up and won't stay in clumps is granular.
- Estimate the particle sizes. Mostly fine-grained is cohesive. Mostly coarse sand or gravel is granular.
- Look for tension cracks and chunks spalling off the face (fissures). Small spalls mean the ground is moving.
- Look for utilities and old backfill (previously disturbed soil).
- Look for layers and which way they dip.
- Look for surface water, seepage and the water table.
- Look for vibration sources: traffic, compactors, pile driving.
Manual tests
- Plasticity: roll a moist sample into a 1/8-inch thread. If you can hold a 2-inch length by one end without it tearing, it is cohesive.
- Dry strength: dry soil that crumbles into grains or powder is granular. Clumps that break only with difficulty point to clay.
- Thumb penetration: Type A (1.5 tsf) indents readily but the thumb gets in only with very great effort. Type C (0.5 tsf) lets the thumb in several inches easily.
- Pocket penetrometer or shear vane: gives a reading in tons per square foot. Rocks and pebbles can throw off the reading, so take several.
- Drying test: dry a sample about 1 inch thick and 6 inches across. Cracks mean fissures. Hard to break means cohesive. Pulverizes easily means granular.
Test fresh, undisturbed clumps as soon as practical after they're dug. In layered soil, classify by the weakest layer, unless a stronger layer lies under a weaker one. Reclassify any time conditions change, such as rain, drying, new vibration or seepage. App. A (c)(4), (5)
At your worksite
- What testing tools do crews carry (penetrometer, shear vane)?
- Does the company treat all soil as Type C unless the competent person tests it?
- Where are soil classifications written down?
4. Sloping and benching
Sloping cuts the walls back far enough that they won't fall in. Title 8 gives four ways to pick the slope. §1541.1(b)
- Don't classify: slope at 1½:1 (34°) using the Type C configurations.
- Classify and use the tables: classify the soil under Appendix A and use the maximum slope in Appendix B.
- Other tabulated data approved by a registered professional engineer. Keep a copy on site while the slope is built.
- Engineer's design: stamped and signed by a registered professional engineer. Keep a copy on site while the slope is built.
| Soil | Maximum slope (H:V) | Angle from horizontal |
|---|---|---|
| Stable rock | Vertical | 90° |
| Type A | ¾ : 1 | 53° |
| Type B | 1 : 1 | 45° |
| Type C | 1½ : 1 | 34° |
Table B-1, for excavations less than 20 feet deep. Over 20 feet, sloping or benching must be designed by a registered professional engineer. Type A short term: ½:1 (63°) is allowed if the excavation is 12 feet deep or less and open 24 hours or less.
Rules that change the slope
- Signs of distress (cracks, sloughing, bulging, spalling, raveling): cut the slope back at least ½ horizontal to 1 vertical flatter than the maximum. App. B (c)(3)(B)
- Surcharge loads (spoil, stored material, equipment, traffic): the competent person decides how much flatter the slope must be and makes sure it gets done. App. B (c)(3)(C)
- Benching: Appendix B shows benching for Type A soil and for cohesive Type B soil. It shows none for Type C.
- Vertical lower portion: in Type A, an unsupported vertical side can be up to 3½ feet high. In Type B and C, a vertical lower portion must be shored or shielded to at least 18 inches above the top of the vertical side.
- Working on the face: no one works on a sloped or benched face above other workers unless the workers below are protected from falling, rolling or sliding material. §1541.1(f)
At your worksite
- Does the company let you use Appendix B slopes, or slope everything at 1½:1?
- Who approves tabulated data or engineered slopes, and where is the copy kept on site?
5. Shoring and trench shields
Shoring holds the walls in place. A shield, or trench box, protects the workers inside it if a wall caves.
Where the design comes from
- Appendices C and D: Appendix C for timber shoring. Aluminum hydraulic shoring follows the manufacturer's tabulated data, or Appendix D if that data can't be used.
- Manufacturer's tabulated data: follow every specification and limit. Any deviation needs the manufacturer's written approval.
- Other tabulated data approved by a registered professional engineer.
- A design approved by a registered professional engineer.
Whichever option you use, the written data or design must be on site while the system is being built. §1541.1(c) Appendix E shows alternatives to timber shoring, and Appendix F is a flowchart for picking a system.
Trench shields
- Don't load a shield beyond its design. Check its rated depth for your soil type in the tabulated data.
- Set it so it can't shift sideways if a wall lets go.
- Protect workers going in and out of the shield. For example, put the ladder inside the box.
- No one in the shield while it is installed, removed or moved vertically. §1541.1(g)(1)(D)
- CAOn a vertically cut trench, the shield must reach at least the catch point (the top edge of the cut). Where the trench is sloped above a vertical lower wall, the shield sides must extend at least 18 inches above the vertical wall. §1541.1(g)(2)
- You may dig up to 2 feet below the bottom of the shield only if it is rated for the full trench depth and there are no signs of soil loss from behind or below it.
Shoring
- Connect members so they can't slide, fall or kick out.
- Install and remove shoring in a way that protects workers. Remove from the bottom up, release members slowly, and backfill as you go. §1541.1(e)(1)
- Digging up to 2 feet below the bottom of the support members is allowed only if the system is designed for the full depth and there are no signs of soil loss.
- CAUprights extend to the top of the trench, with the lower end no more than 2 feet from the bottom. §1541.1(h)
- Damaged parts: the competent person examines them. If you can't be sure they'll hold, take them out of service until a registered professional engineer approves them. §1541.1(d)(3)
At your worksite
- Which shields and shoring does the company use, and what are their rated depths?
- Where is the tabulated data kept on this job?
- Who signals the operator when the box is moved?
6. Access, spoils, equipment and traffic
- Way out: trenches 4 feet or deeper need a stairway, ladder, ramp or other safe way out, placed so no one travels more than 25 feet sideways to reach it. §1541(c)(2)
- Ramps: ramps used only by workers are designed by a competent person. Equipment ramps are designed by a competent person qualified in structural design and built to that design. §1541(c)(1)
- Spoils: keep spoil, materials and equipment at least 2 feet back from the edge, use retaining devices, or both. The spoil is also a surcharge load on the wall. §1541(j)(2)
- Loose rock: scale loose rock or soil off the face, or put up barricades to catch it. §1541(j)(1)
- Falling loads: no one under loads handled by lifting or digging equipment. Stand clear of trucks being loaded or unloaded. §1541(e)
- Equipment at the edge: if an operator can't clearly see the edge, use a warning system: barricades, hand or mechanical signals, or stop logs. Grade away from the excavation when you can. §1541(f)
- Traffic: workers exposed to public traffic wear warning vests or other high-visibility garments. §1541(d)
- CACrossing over: where people or equipment cross excavations over 6 feet deep and wider than 30 inches, provide walkways or bridges with standard guardrails. §1541(l)(1)
- Remote excavations: barricade them. Barricade or cover wells, pits and shafts, and backfill temporary ones when finished. §1541(l)(2)
At your worksite
- Which ladders, ramps or stairs are on site, and who moves them as the trench advances?
- Is there a traffic control plan? Where do stop logs or barricades go on this job?
7. Water, air and nearby structures
Water
- No work in water that has collected or is collecting unless precautions are in place, such as special shoring or shields, pumping to control the level, or a harness and lifeline. §1541(h)(1)
- If pumps keep the trench dry, a competent person monitors them. §1541(h)(2)
- If the work cuts off natural drainage, use ditches or dikes to keep surface water out. After heavy rain, the competent person inspects before anyone goes back in. §1541(h)(3)
- Remember that soil with water freely seeping out is Type C.
Hazardous atmospheres
- Test the air before anyone enters an excavation deeper than 4 feet where low oxygen or a hazardous atmosphere exists or could reasonably be expected, such as in landfills or near stored hazardous substances. Sewers and areas near fuel lines or tanks are other places to suspect. §1541(g)(1)(A)
- Low oxygen means below 19.5 percent.
- Keep flammable gas below 20 percent of its lower flammable limit, using ventilation or other precautions. §1541(g)(1)(C)
- Protect workers with ventilation or respiratory protection, and keep testing as often as needed while controls are in use. §1541(g)(1)(B), (D)
- Where a hazardous atmosphere exists or could develop, keep rescue equipment (breathing apparatus, harness and line, basket stretcher) readily available, and attend it while in use. §1541(g)(2)(A)
- Bell-bottom pier holes and similar deep, confined footing holes: the worker wears a harness with a lifeline that is attended at all times. §1541(g)(2)(B)
- An excavation can also be a confined space. Check whether the confined space rules in Title 8, Article 37 apply.
Nearby structures
- If digging threatens a building, wall or other structure, support it with shoring, bracing or underpinning. §1541(i)(1)
- Don't dig below a footing or foundation unless it is underpinned, it is in stable rock, or a registered professional engineer approves. §1541(i)(2)
- Don't undermine sidewalks or pavement without support or other protection. §1541(i)(3)
At your worksite
- Which gas meter do crews use, when is it bump tested, and what are its alarm set points?
- Where is rescue equipment kept, and who is trained to use it?
- Does the company's confined space program cover excavations?
8. Daily inspections and stopping work
The daily inspection is the competent person's main tool. §1541(k)(1)
When
- Before work starts each day.
- As needed through the shift.
- After every rainstorm or other event that increases the hazard, such as new vibration, heavier loads near the edge, water coming in, or damage to the shoring.
Inspections are required whenever workers can reasonably be expected to be exposed.
What to look for
- Cracks at the surface or in the face, especially ones running parallel to the edge
- The edge sinking (subsidence)
- The face bulging, or the bottom heaving
- Chunks spalling off the face, or raveling: pebbles and small clumps trickling down
- Water seeping in or collecting
- Shoring or shield parts that are damaged, shifted or missing
- Spoil, equipment or materials too close to the edge
- Air test readings that show a hazard
When you find a problem
Get exposed workers out of the hazard area. They stay out until it is made safe. §1541(k)(2) Then fix it: cut back the slope, add protection, pump, ventilate or retest. Inspect again before anyone goes back in.
Section 1541(k) doesn't require a written form. Most employers use one because a dated checklist shows what was checked and when.
You're walking this 8-foot trench before work. Click or tap each hazard you see. Found 0 of 6
If a cave-in happens
- Call 911 and give the site address.
- Don't let others go into an unprotected trench to dig someone out.
- Shut down nearby equipment and keep weight off the edge.
- Account for everyone, and follow your employer's emergency plan.
- Employers must report a serious injury, illness or death to Cal/OSHA immediately, and no later than 8 hours after they know. §342
At your worksite
- Which inspection form does the company use, and who gets it?
- What is the site address to give 911?
- Who reports serious injuries to Cal/OSHA?
Final quiz
15 questions. You need 12 correct (80%) to pass. If you don't pass, you'll see which topics to review and you can retake it. A retake gives you different questions on the same topics. This course has a 30-minute minimum: you can take the quiz as soon as you finish the lessons, but a passing score isn't recorded until 30 minutes after you started.
Final quiz
Answer every question before you submit.