How much does excavation cost in Missouri?
Most excavation in Missouri costs $75 to $180 per hour for a machine and operator, or is quoted as a flat price for the whole job. In Jefferson County and the St. Louis area, a 50-foot residential utility trench typically runs $800 to $2,500, and a 1,500-square-foot foundation dig runs $4,000 to $12,000.
The low end is a mini excavator on a tight lot; the high end is a full-size machine. Rock, depth, access and where the dirt goes decide where your job lands.
Typical prices by job
Jefferson County and St. Louis metro ranges as of 2026.
| Job | Typical range | Notes |
|---|---|---|
| Residential utility trench (50 ft) | $800 to $2,500 | Depends on depth and soil |
| Foundation dig (1,500 sq ft) | $4,000 to $12,000 | Rock adds significantly |
| Site clearing and rough grade (1 acre) | $3,500 to $10,000 | Stumps and demolition extra |
| Pond or retention basin | $8,000 to $25,000+ | Depends on size and depth |
| Hydrovac potholing (per hole) | $250 to $600 | Setup plus 1 pothole |
| Hydrovac slot trenching (per day) | $1,200 to $2,500 | Varies with soil and depth |
Hourly rates by machine
| Machine | Rate | Best for |
|---|---|---|
| Mini excavator | $75 to $110/hr | Tight residential lots |
| Full-size excavator | $120 to $180/hr | Open sites; moves dirt faster |
| Hydrovac | $250 to $450/hr | Digging near buried utilities with water and suction |
What raises the price?
- Rock. Missouri limestone shows up in Jefferson County digs, especially on sloped lots and deeper cuts. Rock costs 30 to 100 percent more to remove than soil, because it needs a hydraulic hammer and slower work. On a $5,000 job, two feet of limestone at the bottom of a foundation cut can add $2,000 to $4,000.
- Clay. Jefferson County clay, common from Festus through Arnold, is slower to dig and load than loose soil.
- Depth. Deeper cuts are slower per yard, and OSHA requires sloping or shoring at 5 feet deep or more unless the cut is entirely in stable rock.
- Access. Fences, narrow gates and trees force smaller machines. A job that takes 6 hours on an open site might take 10 on a tight lot.
- Where the dirt goes. Spreading it on your property costs least. Hauling it to a disposal site can add hundreds to thousands of dollars.
- Buried utilities. Near marked lines, crews expose them by hand or hydrovac first. Three utility crossings take longer than none.
If the job may hit bedrock, read rock excavation cost factors too.
What should the quote include?
Check for each line: mobilization (getting machines to and from the site), machine and operator time, fuel, where the dirt goes and who pays, backfill, and how rock is priced if they hit it. Ask how extra work gets approved.
Watch for these in a low bid:
- No disposal line. You will find out what it costs after the trucks are loaded.
- No site visit. A quote from an address and a phone call is a guess.
- No mention of 811. Missouri law requires a call to 811 at least two full working days before digging.
- No insurance certificate. Ask for proof of general liability and workers' comp before any machine rolls.
When is hydrovac worth it?
Away from utilities, a regular excavator is far cheaper. Near marked gas, electric or telecom lines, a strike is possible, and a gas main strike starts at $25,000 to $150,000 in repairs. Counting that risk, hydrovac is often the cheaper choice. See hydrovac vs. traditional excavation.
Common questions
Is excavation cost per cubic yard or per hour?
Both models exist. Most residential projects are quoted as a flat price after a site visit. Large site work and commercial jobs often run at hourly rates for machine plus operator, $85 to $180 per hour depending on machine size. A flat price is almost always better for homeowners because it caps your total cost.
Why is my quote higher than my neighbor's?
Soil, depth, rock, access and disposal all vary by lot. Jefferson County lots differ in clay, slope, buried fill and rock depth even next door, and what looks like the same job can be completely different 3 feet down.
Does excavation cost include haul-off?
It depends on the contractor. J1S quotes always say what happens to the dirt: spread on site, hauled to the J1S yard, or taken to third-party disposal. If a quote does not address disposal, ask before you sign.
How do I keep excavation costs down?
Give the crew good access and a clear scope, and call 811 early (at least two full working days before digging). The biggest surprises come from rock, utility conflicts and unknown buried objects.
What J1S needs to quote
J1S quotes most Jefferson County excavation jobs within one business day of a site visit. Send the address and access notes (gate width, overhead clearance, neighbors), rough length, width and depth, any soil you know about, known utilities, where the dirt should go, and your target start date. Related: grading vs. excavation and the utility trenching guide.
Sources
- Missouri Revised Statutes, Section 319.026: state law requiring notice to the one-call center at least two working days before excavating.
- OSHA, 29 CFR 1926.652, Requirements for protective systems: protective systems such as sloping or shoring are required for excavations 5 feet deep or more, unless the cut is entirely in stable rock.
- OSHA, 29 CFR 1926.651, Specific excavation requirements: the exact location of underground utilities must be determined by safe means as digging approaches them.