| name | early-phase-enabling-trades |
| description | Sitework, excavation, demolition, environmental abatement, and underground utility guidance for construction PMs and field supervisors. |
Early Phase Enabling Trades
Expert-level guidance for sitework, excavation, demolition, environmental abatement, and underground utilities in commercial/institutional construction. This skill covers the critical first phases of construction that establish the foundation for all subsequent work.
Quick Reference Tables
OSHA Excavation Soil Classification
| Type | Description | Max Allowable Slope | Cohesive Strength |
|---|
| Type A | Clay, silty clay, sandy clay, clay loam (ceite) | 3/4H:1V (53°) | 1.5 tsf or greater |
| Type B | Angular gravel, silt, silt loam, sandy loam, previously disturbed soils | 1H:1V (45°) | 0.5-1.5 tsf |
| Type C | Gravel, sand, loamy sand, submerged soil, unstable rock | 1.5H:1V (34°) | Less than 0.5 tsf |
Reference: Trench Safety & OSHA Requirements
Soil Classification Quick Reference (USCS)
| Symbol | Description | Characteristics |
|---|
| GW | Well-graded gravel | Excellent drainage, high bearing |
| GP | Poorly-graded gravel | Good drainage, moderate bearing |
| SW | Well-graded sand | Good drainage, good bearing |
| SP | Poorly-graded sand | Good drainage, lower bearing |
| SM | Silty sand | Fair drainage, fair bearing |
| SC | Clayey sand | Poor drainage, fair bearing |
| ML | Silt | Poor drainage, low bearing |
| CL | Lean clay | Poor drainage, fair bearing |
| CH | Fat clay | Very poor drainage, variable bearing, expansive |
| OH/OL | Organic soils | Not suitable for structural support |
Reference: Geotechnical Fundamentals
Compaction Requirements by Application
| Application | Minimum % Compaction | Test Method | Lift Thickness |
|---|
| Structural fill under footings | 95-98% Modified Proctor | Nuclear density | 6-8" loose |
| Building pad/slab subgrade | 95% Modified Proctor | Nuclear density | 8" loose |
| Utility trench backfill (pipe zone) | 95% Standard Proctor | Nuclear density | 6" loose |
| Utility trench backfill (above pipe) | 90-95% Standard Proctor | Nuclear density | 8-12" loose |
| Pavement subgrade | 95% Modified Proctor | Nuclear density | 8" loose |
| General site fill | 90% Standard Proctor | Nuclear density | 12" loose |
Reference: Excavation & Earthwork
Shrink and Swell Factors
| Material | Shrink Factor | Swell Factor | Bank to Compacted |
|---|
| Clay | 0.90 | 1.30 | 0.90 |
| Common earth | 0.90 | 1.25 | 0.90 |
| Gravel | 0.92 | 1.12 | 1.05 |
| Sand | 0.95 | 1.12 | 0.95 |
| Rock (blasted) | 0.67 | 1.50 | Variable |
Reference: Excavation & Earthwork
Underground Utility Pipe Materials
| Application | Common Materials | Typical Sizes | Key Considerations |
|---|
| Sanitary sewer | PVC (SDR 35), DIP, VCP | 4"-36" | SDR 35 to 15' depth; DIP for deeper |
| Storm drainage | RCP, HDPE, PVC, CMP | 12"-96" | RCP for heavy loads; HDPE for flexibility |
| Domestic water | DIP, PVC (C900), HDPE | 4"-16" | DIP most common; HDPE for HDD |
| Fire water | DIP, cement-lined | 6"-12" | Typically ductile iron |
| Gas (distribution) | PE, steel | 2"-6" | Yellow PE most common |
| Electrical duct | PVC (Sch 40/80), HDPE | 2"-6" | Concrete encased in traffic areas |
Reference: Sanitary & Storm | Water & Fire | Dry Utilities
Dewatering System Selection
| Groundwater Condition | Soil Type | Recommended System | Typical Depth |
|---|
| Low volume, shallow | Any | Open sumps | 0-6' |
| Moderate volume | Sand, gravel | Wellpoints | 0-18' |
| High volume, deep | Sand, gravel | Deep wells | 15-100'+ |
| Fine soils, low perm | Silt, fine sand | Eductors | 0-60' |
| Contaminated | Any | Contained system | Varies |
Reference: Dewatering Systems
Shoring System Selection
| Excavation Depth | Soil Conditions | Typical System | Design Responsibility |
|---|
| <5' | Type A soil | Open cut or box | Contractor |
| 5-12' | Type B/C soil | Trench box/shield | Contractor |
| 5-20' | Mixed conditions | Sheet piling | Engineer required |
| 10-40' | Tight site, adjacent structures | Soldier pile & lagging | Engineer required |
| 20'+ | High groundwater | Secant/tangent piles | Engineer required |
| Variable | Permanent installation | Soil nail wall | Engineer required |
Reference: Shoring & Excavation Support
APWA Utility Color Codes
| Color | Utility Type | Examples |
|---|
| Red | Electric | Power lines, conduit, lighting |
| Yellow | Gas/Oil/Steam | Natural gas, propane, petroleum |
| Orange | Communication | Telephone, cable TV, fiber optic |
| Blue | Water | Potable water, irrigation |
| Green | Sewer/Drain | Sanitary sewer, storm drain |
| Purple | Reclaimed water | Non-potable water |
| Pink | Temporary survey | Survey marks, proposed excavation |
| White | Proposed excavation | Dig area boundary |
Reference: Utility Coordination & Locates
Asbestos-Containing Materials (Common Locations)
| Material | Friability | Typical Location | Removal Method |
|---|
| Pipe insulation | Friable | Mechanical rooms, ceilings | Full containment |
| Spray-on fireproofing | Friable | Structural steel, decking | Full containment |
| Acoustic ceiling tile | Non-friable | Ceilings throughout | Wet removal |
| Floor tile (9x9, 12x12 VAT) | Non-friable | Throughout building | Wet removal |
| Mastic/adhesive | Non-friable | Under flooring | Leave in place or removal |
| Transite siding/panels | Non-friable | Exterior, mechanical rooms | Wet, intact removal |
| Roofing felts | Non-friable | Roof systems | Wet removal |
| Joint compound | Friable | Drywall joints | Full containment |
| Boiler insulation | Friable | Mechanical rooms | Full containment |
Reference: Asbestos Abatement
Environmental Regulatory Framework
| Regulation | Agency | Applies To | Key Requirements |
|---|
| NESHAP | EPA | Asbestos | 10-day notification, work practices |
| OSHA 1926.1101 | OSHA | Asbestos (construction) | Worker protection, exposure limits |
| OSHA 1926.62 | OSHA | Lead (construction) | Worker protection, medical monitoring |
| RRP Rule | EPA | Lead paint renovation | Certified renovators, work practices |
| TSCA | EPA | PCBs | Disposal requirements |
| RCRA | EPA | Hazardous waste | Manifests, disposal |
| NPDES | EPA/State | Stormwater | SWPPP, inspections, BMPs |
Reference: Lead & Hazmat Abatement | Permits & Regulatory
Pipe Testing Requirements
| Pipe Type | Test Method | Test Pressure/Duration | Acceptance Criteria |
|---|
| Sanitary PVC | Low-pressure air | 4.0 psi, 2 min minimum | No audible leaks |
| Sanitary PVC | Mandrel (deflection) | 5% of ID | Pass without force |
| Storm RCP | Exfiltration | 2' head above GW | <200 gal/inch-dia/mile/day |
| Water main DIP | Hydrostatic | 150% working, 2 hrs | Max allowable leakage per AWWA |
| Water main PVC | Hydrostatic | 150% working, 2 hrs | Max allowable leakage per AWWA |
| Gas PE | Pressure test | 1.5x MAOP, 1 hr | No pressure drop |
| Electrical duct | Mandrel | Per spec | Full pass-through |
Reference: Testing & Inspections
Erosion & Sediment Control BMPs
| BMP Type | Application | Maintenance Frequency | Key Installation Requirements |
|---|
| Silt fence | Perimeter, slope bases | Weekly + after 0.5"+ rain | Trenched 6"+, posts 6' OC |
| Inlet protection | Storm inlets | Weekly + after rain | Filter fabric or gravel |
| Stabilized entrance | Site access points | Daily, add stone as needed | 50' min length, 6" stone |
| Sediment basin | Large disturbed areas | After each storm event | Per SWPPP sizing |
| Erosion blanket | Slopes >3:1 | Inspect weekly | Stapled per manufacturer |
| Concrete washout | Mixer/pump cleaning | Weekly, dispose properly | Lined pit, 10' from drainage |
Reference: Erosion & Sediment Control
Survey Layout Tolerances
| Element | Horizontal Tolerance | Vertical Tolerance | Verification Method |
|---|
| Building corners | ±0.01' (1/8") | N/A | Double-check layout |
| Foundation/footings | ±0.02' (1/4") | ±0.02' | Survey, form check |
| Anchor bolts | ±1/8" | ±1/4" | Template, survey |
| Structural steel base plates | ±1/8" | ±1/8" | Survey, level |
| Underground utilities | ±0.10' | ±0.02' elevation | Grade laser, survey |
| Fine grading | ±0.02'-0.04' | ±0.02' | Laser, string line |
| Paving subgrade | ±0.02' | ±0.02' | Laser level |
Reference: Surveying & Layout
CSI MasterFormat Divisions for Early Phase Work
| Division | Title | Key Sections |
|---|
| 01 | General Requirements | SWPPP (01 57 00), Temporary Facilities |
| 02 | Existing Conditions | Demolition (02 41 00), Hazmat (02 82 00) |
| 31 | Earthwork | Excavation, Shoring, Dewatering, Grading |
| 32 | Exterior Improvements | Paving, Fencing, Site Improvements |
| 33 | Utilities | Storm, Sanitary, Water, Gas, Electric |
Reference: Specifications & CSI Divisions
Detailed Reference Guides
Sitework & Excavation
- Geotechnical Fundamentals - Soil classification, bearing capacity, geotech reports, boring logs
- Excavation & Earthwork - Mass excavation, cut/fill, compaction testing, quantities
- Shoring & Excavation Support - OSHA soil types, shoring systems, monitoring, design
- Dewatering Systems - Wellpoints, deep wells, monitoring, discharge permits
- Erosion & Sediment Control - SWPPP, BMPs, inspections, NPDES permits
Demolition
Environmental Abatement
Underground Utilities
- Sanitary Sewer & Storm Drainage - Pipe materials, installation, testing, manholes
- Domestic Water & Fire Water - Water main, fire protection, testing, disinfection
- Dry Utilities - Electrical duct bank, gas, telecom, joint trench
- Trench Safety & OSHA - Subpart P, competent person, soil classification, protective systems
- Utility Coordination & Locates - 811, potholing, damage prevention, as-builts
Regulatory & Documentation
- Surveying & Layout - Control, benchmarks, layout procedures, GPS, tolerances
- Permits & Regulatory - Demo permits, NPDES, notifications, closeout
- Testing & Inspections - Compaction, pipe tests, video inspection, documentation
- Safety Hazards - Excavation, utilities, demolition, hazmat, equipment hazards
- Specifications & CSI Divisions - Division 02, 31, 32, 33, key specification sections
Integration with Other Skills
This skill works with other construction management skills:
| Skill | Integration Points |
|---|
| construction-safety-management | OSHA requirements, competent person duties, incident investigation |
| vdc-bim-coordination | Underground utility coordination, clash detection, 3D models |
| procore-project-management | RFIs, submittals, daily logs, documentation workflows |
| schedule-management-cpm | Early phase sequencing, critical path, activity durations |
| contract-administration | Differing site conditions claims, change orders |
| claims-delay-documentation | Unforeseen conditions, delay documentation |
Typical Early Phase Sequence
1. Site Mobilization & Setup
├── Establish survey control
├── Install erosion controls
├── Set up construction entrance
└── Temporary facilities
2. Demolition Phase
├── Hazmat surveys (if not complete)
├── Utility disconnections
├── Abatement (asbestos, lead)
├── Selective interior demo
├── Structural demolition
└── Foundation/basement removal
3. Site Clearing & Earthwork
├── Strip topsoil (stockpile or export)
├── Mass excavation
├── Shoring installation
├── Dewatering (if required)
├── Building pad preparation
└── Proof roll and compaction testing
4. Underground Utilities
├── Storm drainage
├── Sanitary sewer
├── Water and fire mains
├── Dry utility duct banks
├── Testing and inspection
└── Backfill and compaction
5. Foundation Preparation
├── Fine grading
├── Subgrade compaction
├── Foundation layout
└── Hand-off to structural
Key Contacts & Coordination
External Coordination
- Geotechnical engineer - Soil conditions, testing, observations
- Surveyor - Control, layout, as-builts
- Utility companies - Connections, inspections, acceptance
- Environmental consultants - Abatement oversight, air monitoring
- AHJ (Building department, fire marshal, health department)
- 811 One-Call - Utility locates
Internal Coordination
- Safety manager - OSHA compliance, JSAs, incident response
- Project engineer - Submittals, RFIs, documentation
- Superintendent - Daily operations, crew coordination
- Scheduler - Activity updates, critical path