How To Dig A Sewer Line Trench

Trenching is the primary step that must precede sewer line replacement or repair. Digging a trench involves using a backhoe, excavator, concrete saw, or handheld trencher to remove the grass, earth, and concrete from the surface to expose the sewer line. The depth of a standard sewer line trench varies depending on the location, size of pipe, climate, and others. However, the depth should range from 1.5 feet to 20 feet deep. Due to this, it’s important to take caution while digging a drain trench.

According to Occupational Safety and Health Administration (OSHA), a trench shield is one of the most important safety precautions to put in place before trenching. OSHA considers trenching as one of the most delicate construction activities because of the depth, buried utilities, and unexpected caving-in. The trench shields help keep the trench walls in place, hence protecting the workers from unexpected trench wall collapse. OSHA advises that trench shields be used for drain trenches that are 5 feet or more.

Materials And Tools Needed For Digging A Sewer Line Trench

If you’re faced with a damaged sewer line in your home, you must note that the cost of replacing the sewer pipe will include trenching charges, which often make a higher total cost. However, with some level of expertise, you could reduce the total cost by handling the trenching personally. First, make sure to buy or rent the necessary tools and materials needed for digging a trench. Here’s a list of the materials and tools needed.

  • Shovel
  • Marking paint
  • Sledgehammer
  • Handsaw
  • Pickax
  • Chain saw
  • Trench shields
  • Soil and gravel
  • Yard trash bags

Step-by-step Guide To Digging A Sewer Line Trench

The following is a step-by-step guide to how to dig drain trenches.

– Identify the Location of the Sewer Line

To begin the trenching for the sewer replacement project, make sure to find the precise spot of the sewer line. A video camera inspection can be conducted to locate the exact position of the sewer line. The video camera inspection is performed by running a camera with a radio transmitter from the sewer clean-out through the sewer line. The signals can be read over the ground by sweeping a locator over the area. Once the sewer line is located, make sure you use the marking paint to mark out the entire area of the sewer line.

– Identify the Areas of the Utility Lines

It is also important to find the location of the utility lines in your yard before digging the sewer trenches. You can put a call through to the local utility locator, and a technician will be sent to you to mark out the gas line, water, electrical line, and others. Also, take note of the landscape lights, irrigation system, and other homeowner-installed services. Endeavor to mark out all the points to prevent digging in the wrong place.

– Get a Permit

In most states, a permit is required before construction work can be done. The permits ensure that safety precautions are followed. Before a work permit is granted, the governing body will send an inspector to visit the trench site to ensure that everything complies with the standard requirements. 

– Dig the Sewer Line Trench

If the sewer line is located beneath a concrete driveway, sidewalk, or slab, the digging process will begin by breaking the concrete with a concrete saw or a sledgehammer. Once the concrete obstructions are out of the way, the soil can be dug up with a shovel or a hand trencher. When digging, make sure to start straight down and reduce sideways digging at the onset. After digging downwards to the extent of access to the sewer line, the trench can be dug sideways. As you dig, it’s possible to come in contact with roots. You can use the chainsaw to cut down big roots. If the roots are small, use the shovel blade for pegging down the roots, then use the handsaw to cut the roots. Clear out the pieced roots into the trash bags.

– Replace the Damaged Sewer Line and Refill the Trench.

As you dig the trench, take note of over-saturated moist soil or strange, unpleasant smell. These are indicators that you’re close to the damaged sewer line. When you notice these, reduce the intensity of the digging to avoid completely breaking the sewer line. Carefully clear out the surrounding of the sewer line to give easy access for replacement. Once that is done, get in touch with a reputable company handling sewer replacement in Maryland. The sewer replacement professional will carefully and expertly replace the sewer line to prevent a big mess.

When the sewer line replacement is completed, inspect the job before covering up the dug trench with soil and gravel. Before pouring in the soil, enclose the pipe with gravel to better shield the sewer line against soil movement. After filling in the gravel, gradually pour soil and compress the soil occasionally while you fill in the trench to avoid future sinking.

Safety Precautions To Consider When Digging Sewer Trench

– Access and Egress

When digging a trench of 4 feet or more, endeavor to set up a means of egress and access. Egress simply means cleared exit path into the trench, while access, on the other hand, means setting up the necessary equipment to enable easy entry and exit from the trench. A ladder is a suitable tool for gaining access to the trench. Ensure the ladder is wooden or fiberglass to prevent electric shock; securely set up the ladder in the trench.

– Temporary Fencing

It’s important to keep children and pets away from the trench. You can set up a temporary fence around the trench area to prevent pets and children from falling into the dug trench. A temporary covering can also be placed over the excavated area to prevent children from falling into the ditch.

In addition, a warning sign and tape can be set around the trench area to alert people of the ongoing project. 


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