Locating or potholing: what differs?
Utility locating marks a buried line's estimated route on the surface with paint or flags. Potholing digs a small hole at a chosen point so the crew can see the line and measure it. Locating comes first and tells the crew where to pothole; potholing confirms the line where it matters, such as under a planned trench.
| Step | What it tells you | What it does not |
|---|---|---|
| 811 locates | Estimated routes of the utilities' own lines | Private lines, or how deep any line is |
| Private locating | The owner's private lines, within the agreed scope | Every unknown line, guaranteed |
| Potholing | The line seen and measured at chosen points | The whole route between holes |
| Survey | Positions or elevations recorded to a reference | Permission to ignore site conditions |
What does an 811 locate tell you?
Missouri 811 passes your dig notice to member utilities, and their locators mark where their lines are expected. The marks carry no depth: Missouri 811 says it does not provide utility depth information, and a line's depth can change along its route.
Follow the current Missouri 811 excavator process for the ticket, the waiting period, and missing or unclear marks. Booking a hydrovac does not replace it, and the area on the ticket must match the actual work.
Which lines need a private locator?
811 does not mark every line on a property. Missouri 811's public and private utility guidance says privately owned lines, such as a feed to a detached garage or pool, can need a private locating company.
Tell the contractor about outbuildings, irrigation, site lighting, past additions, and lines added after the original building. Agree on who arranges private locating, since "utilities marked" can mean different things to different people.
What does potholing add?
Potholing, also called utility daylighting, opens a small hole to expose the line at one point. A hydrovac loosens the soil with water and vacuums it away. The crew then takes the measurements the job needs, such as the elevation of a crossing under a planned sewer trench. Agree on the measurements and their reference point before the crew starts.
A hole confirms one point. Lines can change direction or depth between holes, so name every crossing that needs checking in the scope.
When should you pothole?
Early enough to change the plan: before the trench crew or boring rig commits to a route, or before an addition's footings are set near a service line. OSHA's excavation requirements call for finding the exact location of buried utilities by safe means as a dig approaches them. A painted route does not replace that.
For utility trenching, ask where exposures are needed in the sequence, and agree on protecting the holes, records, backfill, and surface repair.
What to send J1S
The site address, a marked-up plan, the number of exposure points, depths if known, the surface type, and access photos. Say what decision the result must support: a crossing elevation, footing clearance, repair access, or something else.
J1S provides hydrovac excavation across Jefferson County and the St. Louis metro; see the St. Louis hydroexcavation page for metro work. Use the hydrovac quote checklist to organize details, and the utility potholing service page covers truck access and the handoff to the next trade.