What is hydrovacing?
- Can safely replace hand-digging in the hand expose zone.
- Combines water pressure and a vacuum to excavate.
- Suits all sizes of projects.
- Fast, easy and safe when done properly.
- Works well during frozen ground conditions.
- Use a wand tip and suction hose covered with Teflon® or rubber.
- Keep wand in motion at all times, with the wand tip at least 0.3 metres (one foot) from the line.
- The wand tip should have a three-jet tip or an agitating spinner assembly.
- Do not exceed pressures of 1,500 PSI or temperatures of 60ºC.
- Reduce pressure to finish exposing the gas line.
- Damage to the pipe or coating must be reported to ATCO Gas.
- Must carry a Material Safety Data Sheet (MSDS) for natural gas and be aware of emergency procedures.
- Cover and barricade all open holes and excavations.
- Responsible for the public’s safety until inspection and backfilling is complete.
- Responsible for major damage to a natural gas line – including costs of repair, gas loss, customer re-lights, and emergency response.
- Minor damage to the gas line coating will be repaired at no charge to the contractor.
- Must contact ATCO Gas immediately if damage occurs.
Only after hand exposing
- Hand expose the gas line first by shovel or hydrovac.
- You must see the line to verify its location and depth.
- Only then can you use machines to excavate.
- Two workers should always be present – the machine operator and a spotter.
- Remove small layers of soil at a time.
- Dig parallel to the buried line. Stay at least 0.6 metres (2 feet) away from the line.
- Watch the excavation at all times for movement (cable contact), soil consistency (trench line) or foreign objects identifying underground facilities.
- Expose the gas line by hand or hydrovac to create a day-lighted area.
- This area should extend at least 0.3 metres (one foot) on all sides around and below the pipe – one metre (three feet) is better.
- The drill path must cross under the pipe in this day-lighted area.
- Keep a close watch on the area below the pipe to ensure the drill-head does not hit the gas line.
- Watch during both the initial push and the pull-back.
- Never assume the gas line will be at the same depth on either side of the day-lighted area.
- If drilling within one metre (three feet) of the outside edges of the natural gas locate marks, you must hand expose.
- Hand shovel or hydrovac a number of points along the gas line.
- Number of day-lighted points depends on the drill path and depth of the gas line.
- At minimum, points must be exposed every 30 metres (98 feet) along the line.
- For shorter jobs, points must be exposed more closely.
Temporary Support Systems
What are temporary support systems?
- Installed before excavating below a natural gas line.
- Also used during the backfill.
- Prevent gas lines from sagging, bending or deflecting.
- Usually made of steel or wood.
Is it always required?
- Depends on the length of the gas line.
- Contact your local ATCO Gas office.
- We will walk you through the requirements, methods and materials.
An ATCO Gas representative must inspect your temporary support systems.
Call ATCO Gas
- Before you backfill around a natural gas line.
- If you discover a natural gas line with less than 0.6 metres (two feet) of cover.
Contact your local ATCO Gas office.
- Compact the fill under the gas line to provide support.
- Do not interfere with gas lines.
- Do not add to the depth of cover without ATCO Gas’s permission.
- Use clean, lump-free material to cover the line.
- Do not place frozen dirt on the line.
New Homes and Buildings
- Very common
- A type of plastic pipe
- Various colours: yellow, black, orange, peach
- Appears as rough steel or coated (tar, grey paper, yellow jacket, blue, red, green)
Polyvinyl chloride (PVC)
- A type of plastic pipe installed in the mid-1960s
- Various colours: white, purple, grey, light blue, peach
- ATCO Gas must supervise any excavation around PVC
- Call your local ATCO Gas office if PVC is listed on your locate slip
- Call two full working days ahead
- Very rare
- Appears as light grey metal or covered with a yellow jacket