Utility locates before a Calgary sewer dig: public and private

01 /Why does a Calgary sewer dig need two different locates?

Because the buried lines in your yard have two kinds of owner. Gas, power, telecommunications and other facilities belong to utilities registered with Utility Safety Partners, which passes locate requests to them. The lines that belong to you do not appear in that system. Utility Safety Partners' FAQ says its locators cannot mark privately installed lines, secondary lines such as electrical lines past the meter, or customer-owned utilities, and gives water and sewer lines past the shut-off at the property line as the example.

So a fully marked front yard can still hide the one pipe the job is about, plus a garage feed, a sprinkler system, a gas line to a barbecue or an old abandoned service. The public request protects the crew from the utilities' lines; the private locate finds everything else, starting with your lateral.

02 /How do you request a public locate through Utility Safety Partners?

The person disturbing the ground submits a locate request online through Utility Safety Partners or by phone at 1-800-242-3447, which its homeowner page lists as staffed Monday to Friday, 8:00 a.m. to 4:30 p.m. On a contracted job that is the contractor. The request describes the dig area; Utility Safety Partners notifies the member utilities, which mark their lines or send clearances.

• Notice: at least three full working days before the dig for a routine request. Weekends and holidays do not count.
• Busy season: Utility Safety Partners has posted that high volumes can stretch response times to 5 to 10 business days. Calgary's main digging season, late spring through early fall, is when the wait is most likely to stretch.
• Cost: its FAQ says utilities generally do not charge to mark their own lines, though locates requested outside normal hours may carry overtime charges.
• Paperwork: each utility's locate documentation says when the locate expires. If ground disturbance continues past that date, request a relocate ticket.

03 /What happens with emergency locates when sewage is backing up?

Utility Safety Partners runs emergency and priority tickets for urgent digs. Its FAQ defines an emergency as a threat to life, health, property or the interruption of critical services, and for an emergency ticket the excavator and equipment must be on site, or on the way to arrive, within two hours of the request. A priority ticket is for work that will start more than two hours but less than three business days after the request.

An active backup into a basement is often handled first without digging: clear the line by augering or jetting from a cleanout, camera it, and then plan the excavation on a normal or priority ticket. Whether a given dig qualifies as an emergency is the excavator's call under the rules, not a shortcut to skip the wait. If you are in the middle of a backup, CalgarySewers.com covers the first steps.

04 /How does a private locate find your sewer lateral?

A private locator finds a sewer lateral by pushing a small radio transmitter, called a sonde, down the pipe on the camera cable and tracing its signal from the surface with a receiver. At each point the operator marks the ground and reads an estimated depth. Most lateral materials, including clay, PVC and liners, are non-metallic, so a signal cannot be put onto the pipe itself; the sonde travels inside instead.

1. Mark the sonde position every few metres and wherever the pipe turns, not just at the two ends.
2. Record depth at the foundation wall, mid-yard and near the property line.
3. Note the counter distance at each mark so defects in the footage can be placed in the yard.
4. Mark every other private line the locator finds, not only the sewer.
5. Photograph the marked yard from two angles with a tape measure or known objects in frame.

Depth readings from a sonde are estimates, and metal nearby, a deep pipe or a steep drop can throw them off. Treat them as planning numbers until the pipe is exposed. The soils and depth page explains why Calgary laterals commonly read deeper than owners expect, and finding where your sewer line runs covers the indoor clues and City records that narrow the search before a locator arrives.

05 /What rules apply when digging near the marks?

Utility Safety Partners tells homeowners that when digging within one metre either side of a locate mark, or within five metres of a high-pressure pipeline, the line must be exposed with hand tools to confirm its exact location and depth. Alberta's OHS Code sets the same principle for employers: mechanical excavation is not allowed inside a buried facility's hand expose zone until the facility has been exposed by hand digging, by a non-destructive method the owner accepts, or by an equivalent method.

• Hydrovac is the common non-destructive method on Calgary jobs: pressurized water loosens soil and a vacuum truck removes it, exposing the line without contact from a bucket.
• Marks get destroyed as a trench advances. The Code requires the employer to re-establish locate marks if work moves or destroys them.
• Crossings are normal. A sewer trench from the house to the street often crosses the gas service at right angles. The crew exposes it, supports it across the open trench and protects it during backfill.
• Frost changes the method. In winter, hand exposure through frozen ground is slow, and hydrovac or thawing is often used. See winter replacement.

06 /How do locates fit into the replacement schedule?

Locates are usually the fixed wait in the middle of the job, so book them as soon as the scope and start date are firm. Three full working days is the minimum; in summer, plan for longer. The Replacement Timeline Planner uses “allow several business days” for this step and notes that emergency locates exist, and the Permit & Locate Checklist keeps the public request and the private locate as separate items so neither is forgotten.

If a job slips past the locate expiry, a relocate ticket is needed before digging resumes. That is a common snag when a trench waits on an inspection or a cold snap. Ask your contractor how they will handle it if the schedule moves.

FAQQuestions people ask