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San Francisco County, CA Contractor directory
Excavation contractors in San Francisco County, CA
3 verified excavating and site work contractors serving San Francisco County.
County excavation guide
Ground conditions and project requirements in San Francisco County
Use this local research to understand soil, seasonal constraints, permits, and jobsite logistics before choosing a contractor.
Skip to 3 contractorsSoil Regime ProfileEPA Ecoregion 34, 75 (Western Gulf Coastal Plain, Southern Coastal Plain)
Gulf Coast Flatwoods & Deltaic Clay
Dominant Soil Order: Alfisols / Vertisols
Parent Material: Quaternary Coastal Deltaic Clay, Silt, and Low-gradient Marine Sand
The Gulf Coast flatwoods and deltaic corridor are defined by low relief, slow surface runoff, and high groundwater tables that often sit within 1 to 3 feet of the surface. Subgrade soils consist of heavy, fat clays (Lake Charles and Beaumont series) with severe shrink-swell characteristics and low unconfined compressive strength. Detention pond excavation, mass drainage ditching, and pump stations represent a huge portion of site earthwork. Saturated ground conditions require the use of wide low-ground-pressure (LGP) tracks and timber crane mats to prevent sinkage. Trenching for deep utilities requires continuous sheet piling or trench shoring combined with well-point dewatering to manage high hydraulic inflow and sand boiling.
Geographic Footprint:Coastal Texas (Harris, Galveston, Jefferson, Brazoria), Coastal Alabama (Mobile, Baldwin)
Geotechnical Baseline
Physical Ground Conditions & Soil Properties
Shallow Bedrock (<50 in)
15.1%of county land area
Moderate rock encounters along ridges and upper slope shoulders.
High Shrink-Swell Clay
11.2%expansive soil
Moderate shrink-swell; verify plasticity index on structural fill.
Median Water Table Depth
0inches from surface
Shallow water table; active dewatering or sumps needed for deep trenching.
Hydric / Wetland Soils
3.1%hydric coverage
Indicates poor natural drainage and potential jurisdictional wetland pockets.
Steep Terrain (Slope >15%)
32.1%of terrain
Mountain/hilly terrain; terracing, benching, and tracked haulers frequent.
Septic Severe Limitations
42.0%severe rate
Standard gravity absorption fields viable in majority of soil types.
Dominant Soil Textures:LoamSandy loamClay
Surface Stones / Boulders: 6.7% coverage
Compliance & Permitting
Earthwork Regulations & Permit Thresholds
Stormwater & Erosion Control
SWRCB Construction General Permit Order 2009-0009-DWQ (as amended; NOI + SWPPP required ≥1 acre; LRP applies)
Administers NPDES stormwater discharge coverage for land-disturbing construction activities.
State Threshold:1.00 Acre
Local Threshold:Follows state
Grading Permit: No separate county grading permit
Onsite Wastewater & Utilities
San Francisco County Environmental Health / Regional Water Quality Control Board
Jurisdiction over septic tank permits, soil evaluation perk tests, and drainfield sizing.
Housing on Septic:10.0%
Soil Evaluation:OWTS Policy + county OWTS management plan: site/soil evaluation by licensed professional; percolation testing per county LAMP
811 One-Call Requirements
USA North 811
Mandatory notice window: 48 hours prior to mechanized earthwork (excluding weekends and legal holidays).
Licensing & Clearing Permits
Contractor License Threshold: Required for earthwork contracts exceeding $0 in California.
Burn Permit Season: Residential pile burning generally Nov–May (per-burn day authorization by local AQMD/CAL FIRE unit); Jun–Oct bans commonAuthority: CAL FIRE / county Air Pollution Control District burn permits; no-burn days by AQI forecast
Weather & Ecology
Seasonal Constraints & Clearing Windows
Design Frost Depth
0inches
Building code minimum depth for footing frost protection.
Frozen Ground Days
0days / year
Typical days with sub-freezing soil conditions affecting digging.
Wet Season Months
January, February, March, November, December
Peak precipitation window requiring sediment traps and soil aeration.
Supply Chain & Hazards
Logistics, Aggregate Sources & Geohazards
Aggregate & Material Supply
Tidewater San Francisco
Nearest active quarry: 3 miles haul distance.(29 active crushed stone/sand operations within 50 miles).
Flood & Hazard Overlay
FEMA 100-Yr Flood:8.4%(100% NFHL digital map coverage)
NWI Wetlands:24.3%jurisdictional coverage
Karst Terrain & Sinkhole Risk: Low
0.0% of county underlain by soluble carbonate rock formations.
HUC8 Primary Watersheds:San Pablo Bay, San Francisco Bay, San Francisco Coastal South
Public conservation land: 24.1% (USGS PAD-US).
Area-specific FAQ
Do I need to call before digging in San Francisco County?
Yes. You should contact USANorth / California 811 at least 2 working days before any digging so underground lines can be marked.
How deep do footings need to be in California?
In California, footings typically need to extend below the frost line, which is around 18 inches here. A local contractor will confirm the code requirement for your site.
Verified local listings
Excavation contractors serving San Francisco County
3 verified listings
