Utility & Process Line Daylighting · Cambridge
Utility and Process Line Daylighting in Cambridge
In a forty-year-old plant yard the drawing shows what was there when the plant opened. Daylighting shows what three tenants have added and abandoned since.
Daylighting is a vertical hole, typically around 300 mm (12 in) across, cut with pressurised water and vacuum straight down to a buried line until it is visible and can be measured. It is the only method that gives depth, since a locate marks position on the surface and nothing else, and in Cambridge it is the only method that reliably tells a facilities manager what is actually under the yard. Industrial sites accumulate services: every tenant adds compressed air, process water, a new feeder or a fibre run, and few of them update the master drawing. The public locate covers the utilities to the meter. Past the meter, the test hole is the record.
What a daylighting job involves here
- One Call locate plus a plant review. The Ontario One Call request for the public services, and the owner's drawings and a private locate for everything inside the fence. On most industrial jobs the plant's maintenance or facilities group walks the yard with us before the holes are set out.
- Holes where the consequences are. At each point where a new pad, footing, trench or drill path crosses a fire main, a process line or a feeder; at the entry and exit of a proposed bore; at each caisson location. The count comes from the drawings and is agreed before the truck is booked.
- Pavement and plating. Yards are paved, so each hole is saw-cut first and plated at the end of the window so trucks and forklifts can cross it. Restoration is agreed at quote stage.
- Records. Depth to top of line, offset from a fixed reference, material, size, condition and photographs, in a format the engineer and the plant can keep. Many Cambridge plants use the daylighting program to correct their master drawing.
Industrial yards, the 401 and the river towns
In Hespeler and along Pinebush and Boxwood the targets are fire mains, process water, compressed air and private feeders, and the holes are cut in production windows with the yard still running. Along the 401 and Franklin Boulevard the yards are larger, the runs are longer and the daylighting is often ahead of directional drilling for a new feed or a gate system. In Galt and Preston the problem is age rather than tenants: mill-era services, stone foundations and abandoned lines that no locate marks, in river-deposited ground that changes from gravel to silt across a lot, with the water table close to the surface near the Grand and the Speed.
What sets the time and the quote
Depth above all. A telecom duct at 600 mm (2 ft) in granular backfill is a short hole; a fire main at 1.8 m (6 ft) in wet silt is several times the time and the slurry. Hole count, saw-cutting and plating, off-hours windows, access and hose run, whether a Highway Occupancy Permit is needed for any holes in the right-of-way, and whether the slurry may be contaminated and need a particular receiving facility all go into the written quote.
Frequently asked questions
Can hydrovac damage a fire main or a process line?
Done correctly, no. Water pressure and temperature are held within limits that will not harm ductile iron, PVC, coated steel or cable jackets, and the wand keeps moving rather than dwelling on one point. Where the plant or a utility owner has its own requirements for work near its lines, they are followed.
How many test holes does a new pad or addition need?
One at every point where the footprint or its footings cross a known or suspected line, and more where the drawings are unreliable. The count is set from the drawings and the plant walk, and adjusted if the first holes find something unexpected, which in an older yard they often do.
Will the records help us fix our site drawings?
Yes. Each hole is recorded with depth, offset, material, size and photographs, and the holes can be picked up by a surveyor for coordinates. Several Cambridge plants have used a daylighting program as the basis for a corrected utility plan.
Serving Cambridge and surrounding areas. Contact us for a no-obligation quote specific to your property.