Excavation near you

No excavation should start until public lines are marked. In Ontario, a free locate through Ontario One Call is required by law at least 5 business days before digging, and in Quebec the RBQ asks contractors to request one from Info-Excavation at least 4 business days ahead. Ontario's guidance for construction projects adds that employers must make sure all gas, electrical and other services are located and marked in and near the area to be excavated. Marks are only approximate, so crews expose lines by careful hand or vacuum digging when working close to them.

If a gas line is hit, leave the machine off, get everyone away from the area and out of the wind, and call emergency services and the gas utility from a safe distance; don't try to stop the leak or bury it. If a power line is struck, stay clear of the equipment and anything touching it. Even a scrape on a line or its coating needs to be reported to the owner of the line, because damage that doesn't leak today can fail later.

Soil that looks solid can give way in seconds, especially in wet, sandy or previously dug ground, and Ontario's Ministry of Labour warns that workers can be critically injured or killed in excavation cave-ins. Its guidance under the Construction Projects regulation, O. Reg. 213/91, says never to enter a trench deeper than 1.2 metres (47 inches) unless the walls are sound, made of solid rock, properly sloped, shored or protected by a trench box, and to keep heavy equipment, excavated soil or rock and construction materials at least one metre from the upper edges.

Other provinces set their own rules through their workplace safety regulators, and a professional crew should explain how the walls will be protected before anyone goes in. As a homeowner, stay out of the trench even to take a quick look, keep children and pets away, and make sure an open excavation is fenced or covered at the end of each day.

The soil beside and below a footing is part of what holds a house up. Dig close to a neighbour's foundation, or deeper than it, and that support can slip away, leading to cracks, settlement or worse. On tight city lots, how the soil is held back matters as much as how the hole is dug, and it is a question for a structural or geotechnical engineer, not something to improvise on site.

Every excavation produces soil, and the cheapest place for it is usually back on the same property, as backfill or grading material, as long as it's suitable. What can't be reused has to go somewhere legitimate. In Ontario, excess soil is regulated under O. Reg. 406/19, On-Site and Excess Soil Management. The province defines excess soil as soil that has been dug up, typically during construction, and must be moved off-site because it can't or won't be reused there.

The rules require excess soil to meet quality standards and to go to an appropriate reuse site with the site owner's written consent, or else to a licensed disposal facility, and some projects must file notices in a public registry. There are exemptions for small projects, including those removing less than 100 cubic metres sent directly to certain waste disposal sites. Other provinces and many municipalities have their own soil and fill rules. Ask your contractor where the soil will go, and if the site once had an oil tank or other contamination, have it tested before any soil leaves.

A new foundation, an addition or an underpinning job needs a building permit, and the excavation is usually inspected as part of it. Pools often need their own permit and must meet the municipality's pool fencing rules before they are filled. Work that crosses a sidewalk, lowers a curb or reaches into the road allowance to connect services generally needs separate approval from the city.

Many municipalities also protect trees, including their root zones, so digging near a large tree on your lot or a neighbour's can require a permit or an arborist's plan. Bringing in or removing fill can trigger a site alteration by-law, covered on the grading page. Your contractor or designer should list every approval before the job is scheduled.