Site Investigation
Test Pit & Perc Test Excavation
Princeton Excavation digs test pits for perc tests, soil logs, and structural investigations across Mercer, Somerset, and Middlesex County. Your engineer or the township health department sets the appointment; we're there with the machine when they are, open the pit so they can read the soil, and backfill clean when the observation is done.
What the visit covers
A test pit is a short job where the timing and the read both have to be right. Here's what we bring to it.
There When the Witness Is
Perc tests and soil logs happen with your engineer or a health department witness standing at the hole. That appointment is fixed, so we treat our arrival the same way: machine on site and ready at the set time.
Pits Cut for a Clean Read
We dig to the depth the engineer calls, keep the walls clean, and bench where needed, so the soil log, horizons, and any seasonal high water table signs are readable and safe to observe.
Pot-Holes and Footing Pits
Beyond perc work: utility locating pot-holes dug carefully by hand and bucket, and soil investigation pits at footing locations for structural engineers checking bearing conditions.
Small digs, fixed appointments
A test pit is a small dig with an expensive audience. The engineer is billing time, the township witness has limited windows, and a missed slot can push a septic design or a permit back weeks. Homeowners usually hire a dig crew for this exactly once, so the only thing that matters is picking one that shows up. We schedule the machine against the appointment and hold it.
Where we work
The dig itself is light on the property. A tracked mini excavator walks in, opens the pit where the engineer staked it, and sits quiet while the soil gets logged. When they're done, the spoil goes back in the order it came out, tamped, with the surface left slightly proud so it settles flush. If the results lead to a septic install or foundation work later, we already know the ground.
How a job goes
From the first call to a clean handover
1. Site Walk
We come look at the property by appointment, check the access and any constraints, and go over your plans or what you have in mind.
2. Marking & Layout
We set the layout on the ground with laser accuracy. Depths, lines, and elevations are marked before anything gets dug.
3. The Work
We bring the right machine for the access, lay ground protection where it's needed, and keep the mess around lawns, trees, and hardscape to a minimum.
4. Clean Handover
You're left with a site that's ready to go and a yard that's still in one piece, set up for whatever's next.
Frequently Asked Questions
Your engineer typically arranges the witnessed test with the county or township health department. Once that date is set, we book the machine against it and coordinate directly with the engineer. If the window moves, we move with it.
The engineer specifies it. Perc and soil-profile pits go deep enough to log the horizons and check for seasonal high water table evidence; footing investigation pits go to whatever depth the structural engineer needs to see. We dig to their number and bench the pit where depth makes that the safe way to read it.
Backfilled the same visit, tamped in lifts, raked out, and the location marked if the engineer wants to find it again. We mound the surface slightly because fresh backfill settles; within a season it sits flush with the lawn.
Service Areas
- Princeton· Mercer County
- Hopewell Township· Mercer County
- Montgomery & Skillman· Somerset County
- West Windsor· Mercer County
- Lawrence Township· Mercer County
- Pennington· Mercer County
- Robbinsville· Mercer County
- Hamilton Township· Mercer County
- Plainsboro· Middlesex County
- Cranbury· Middlesex County
- South Brunswick· Middlesex County
- Hillsborough· Somerset County
- Ewing· Mercer County
Princeton, Hopewell Township, Montgomery & Skillman, and surrounding Mercer and Somerset County, NJ.
Test date on the calendar? Book the machine now and the pit will be open when your engineer arrives.
Owner-operated and by appointment. Tell us about your project and we'll walk the site with you.