Built to spec
Built to your engineered drawings, survey, and the real site conditions, not a one-size-fits-all approach forced to fit.
Commercial & Heavy-Civil Construction
Test Pits and Site Investigation
We excavate, log, sample, expose, backfill, and restore test pits for commercial, industrial, municipal, and heavy civil investigations across Toronto, the GTA, and Ontario, giving project teams direct access to shallow soil, fill, foundations, utilities, and groundwater conditions.
- Licensed, Insured & WSIB-Covered
- 20 Years in Business
Get a Quote
Tell us what you need and we’ll get you a quote. Licensed, insured & WSIB-covered · Free, no-obligation quote & on-site assessment.
Get a Quote
Licensed, insured & WSIB-covered · Free, no-obligation quote & on-site assessment.
20 Years in Business
Licensed, Insured & WSIB-Covered Completed to code & Ontario requirements Completed on site and built to the drawings Performed & installed on site across Ontario
Why Harrowgate Group
What to expect from test pits and site investigation
Made to last
Durable materials and methods chosen for the load, traffic, and environment on site.
Quote-ready
Send specs, drawings, or photos and get a free, no-obligation site visit and estimate with no guesswork.
Code-conscious
Installation and site work completed in accordance with Ontario requirements.
Our Process
How we plan and deliver test pits and site investigation
Test pits are controlled exploratory excavations that expose shallow subsurface conditions for visual logging, bulk sampling, measurements, and constructability review. Harrowgate excavates and restores test pits directly across Toronto and the GTA for geotechnical, environmental, structural, utility, pavement, and excess soil investigations.
- 01 Send your inquiry, a few photos or a description of the site.
- 02 We come out, assess the site, take measurements, and confirm the scope.
- 03 We complete the test pits and site investigation on site, to the load and finish the job needs.
- 04 We install it, finish to grade, and clean up, one accountable crew, start to finish.
Local Context
A closer look at test pits and site investigation
Scope
Understanding test pits and site investigation
How we excavate and document a test pit
We review the investigation plan and locates, mark the excavation, establish traffic and exclusion controls, remove surface materials separately, excavate in observable lifts, place spoil in controlled zones, allow the consultant to log and sample safely, record seepage and obstructions, then backfill, compact, and restore the surface.
Nobody enters an unsupported pit. Samples and measurements are obtained from outside using the excavator bucket, remote tools, or a designed and protected excavation arrangement. The operator exposes utilities or foundations incrementally and follows the spotter’s direction. Different soil horizons, pavement, topsoil, impacted material, and debris are kept separate. Water is contained or managed under the approved plan. Before backfill, photographs capture depth, faces, samples, and features with a scale and location reference.
Ontario excavation and investigation requirements
Test pits follow Ontario Regulation 213/91 excavation requirements, the engineer or qualified person’s program, O. Reg. 153/04 where the pit supports a regulated Phase Two ESA, applicable OPSS excavation and backfill provisions, utility-owner rules, excess soil requirements, and municipal permits or restoration standards.
O. Reg. 153/04 requires documentation for each test pit, including contractor, equipment, cross-contamination controls, and sample frequency. Excavation depth, soil type, water, adjacent loads, and access determine sloping, shoring, or trench-box requirements, but observation is normally performed from the surface. Public right-of-way pits require accepted traffic control and restoration. Backfill material and compaction follow the project specification, with separate treatment for pavement, concrete, topsoil, or landscaped finishes. Spoil cannot be assumed reusable until its geotechnical and environmental suitability is known.
Test-pit failures we prevent
Test pits fail when utility clearance is incomplete, workers enter unsupported cuts, mixed spoil destroys sample value, seepage destabilizes the side, contaminated soil spreads, or loose backfill settles under pavement. We prevent these outcomes through incremental excavation, exclusion, segregation, consultant observation, and specified compaction.
A locate mark identifies a corridor, not exact depth, and private services or abandoned lines may be absent. We daylight carefully and stop on unknown utilities, tanks, voids, or odour. Excavated faces can change rapidly in fill, sand, or saturated soil, so no one relies on a clean-looking wall. If the pit must remain open, it receives designed support, fencing, covers, drainage, and inspection appropriate to the exposure. Most investigation pits are logged and closed the same shift to reduce risk.
Planning test pits and site investigation? Talk it through with our team.
Where test pits provide the best information
Test pits are used to confirm footing dimensions, pavement buildup, fill thickness, buried foundations, utility depth, soil stratigraphy, boulders, topsoil, groundwater seepage, contamination, and available borrow or excess soil. They support buildings, roads, shoring, demolition, remediation, servicing, and site redevelopment.
Geotechnical programs use bulk samples and direct soil exposure where shallow variability matters. Environmental programs target staining, tanks, process areas, or fill and may collect discrete samples from the excavator bucket. Structural investigations expose existing footings for underpinning design without undermining bearing. Utility investigations verify crossings before tender or excavation. We choose test pits when lateral visibility and sample volume outweigh the disturbance, and boreholes when depth, access, or continuous support make open excavation impractical.
Have drawings for test pits and site investigation? Send them over and we will scope it.
FAQ
Test Pits and Site Investigation FAQ
What can a test pit show that a borehole cannot?
A test pit exposes a broad face and plan area, making lateral soil changes, debris, boulders, fill structure, footing geometry, utility construction, seepage, and pavement layers directly visible. It also yields large samples. A borehole reaches greater depth with less disturbance and can support in-hole tests or monitoring wells.
How deep can a test pit be excavated?
Depth is limited by the investigation objective, soil, groundwater, adjacent loads, equipment reach, access, and the excavation-protection method. There is no safe universal depth. Most pits are designed for observation from the surface. Any required entry needs a compliant, specifically protected excavation and separate work plan.
Can someone enter a test pit to collect samples?
Not by default. Samples are normally obtained from the excavator bucket or with remote tools while personnel remain outside the unsupported excavation. Entry is permitted only when the excavation has compliant sloping, shoring, or shielding, safe access, inspection, and all other required controls for the actual soil and depth.
How are underground services protected during test pits?
We review public and private locates, records, owner knowledge, and surface evidence, then expose the area incrementally using non-destructive methods where required. Locate tolerance zones are respected. The operator and spotter stop on any unknown line, duct, concrete encasement, warning tape, or change in soil.
Can excavated test-pit soil be placed back in the hole?
Only if the consultant and project requirements accept its geotechnical and environmental suitability. Soil is kept separated by horizon and contamination status during investigation. Organic soil, debris, frozen material, or impacted material may be unsuitable. Approved backfill is placed in controlled lifts and compacted to the restoration specification.
How long is a test pit left open?
Most investigation pits are logged, sampled, photographed, and backfilled during the same shift. If a pit must remain open, it needs a planned protection system, secure fencing or covers, drainage, lighting where applicable, and competent inspection. Schedule convenience alone does not justify leaving an exposed excavation unattended.
What information is needed to plan test pits?
Provide coordinates, purpose, target dimensions and depth, utility information, expected soil and groundwater, environmental sampling needs, access, spoil handling, observer availability, traffic control, and restoration standard. Existing pavement, contaminated material, shoring, dewatering, imported backfill, and compaction testing are important scope drivers.
Still have a question about test pits and site investigation? Ask our team directly.
Explore
Related Harrowgate services
Deeper geotechnical boreholes and testing, deeper geotechnical boreholes and testing
Contamination-focused investigation, contamination-focused investigation
Continuous subsurface sampling, continuous subsurface sampling
Characterization and movement planning, characterization and movement planning
Production excavation after investigation, production excavation after investigation
Our Work
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Commercial and heavy-civil construction delivered for developers, contractors, property managers, and municipalities.
Get a quote for test pits and site investigation
Send drawings, a site plan, or a description of the scope. Harrowgate Group is licensed, insured, and WSIB-covered.
Licensed, Insured & WSIB-Covered, work managed and documented on every job
Send your project details
Tell us what you need and we’ll get you a quote. Licensed, insured & WSIB-covered · Free, no-obligation quote & on-site assessment.
Test Pits and Site Investigation Across the GTA
View all service areas →Harrowgate Group provides test pits and site investigation, delivered and installed with quote-ready support across Toronto and surrounding Ontario communities.
