Trenching
The cost to dig a trench runs about $800 for 100 linear feet. This is the traditional method of sewer line installation: a plumber digs a trench in which to install the new piping system.
The total expense depends on the length and depth of the trenches needed. This price usually doesn’t include removing landscaping or hardscaping before digging. Cleanup costs for dirt and gravel are also a factor.
Another option for replacing an existing sewer line is trenchless installation. These modern technologies are more expensive than digging a trench, but they come with fewer cleanup costs. Trenchless methods involve either relining an unbroken pipe or using a new pipe to burst the old one from the inside. These methods can cost anywhere from $960 to $1,600 for 100 linear feet.
Backflow Preventer
Installing a backflow preventer costs $125 to $900, plus $25 to $250 for labor. A backflow preventer keeps waste flowing toward the city sewer line, away from your home.
Sewer Cleanout
The price to install a sewer cleanout averages $500 to $2,000. This estimate typically includes pipes and materials, equipment, tools, and labor. Plumbers use this access point to remove clogs in the line.
Materials
The type of piping you use for your sewer line impacts your total cost. There is a variety of common sewer piping materials that vary in price.
PVC piping: $0.50–$5 per linear foot, durable and affordable
Polyethylene: $2–$5 per linear foot, better heat and cold durability than PVC
Cast iron: $2–$10 per linear foot, cheaper than cooper, but subject to corrosion
Copper: $20–$30 per linear foot, best quality, longest-lasting option