Scope

• Source: the public sanitary sewer main, owned by a municipal or district sewer authority
• Delivery: gravity lateral from the building, a cleanout near the property line or right-of-way edge, and a tap or wye on the main
• Alternatives: where no public sewer exists, an onsite system serves the building; see Onsite Septic Systems
• Interface: the building drain and building sewer inside and outside the foundation are covered in Sanitary and Vent Piping

Terminology

• Lateral / side sewer / building sewer: pipe from the building to the main
• Wye / saddle: fitting that connects the lateral to the main
• Cleanout: access fitting for cleaning and inspection
• Property line cleanout: cleanout at the edge of the right-of-way or easement
• Backwater valve: protects a building from sewer surcharge
• Abandoned lateral: a lateral taken out of service and capped

Components

• Lateral pipe: PVC or other approved sewer pipe in bedding; see Pipe Bedding
• Cleanouts: at the building, at changes of direction, and at the property line where the agency requires
• Connection: tap, wye, or manhole connection to the main
• Backwater valve: where the building is below the manhole rim or the main
• Tracer wire: with buried plastic sewer pipe

Coordination

• Slope examples: 1/4 in. per ft (2 percent) is common; one agency sets a normal slope of 1/4 in. per ft with a minimum of 1/8 in. per ft; another requires 2 percent for 4 in. pipe and 1 percent for 6 in. pipe
• Cover examples: 3 ft over the pipe is a common minimum, including under traffic loads
• Cleanout location: many agencies place the cleanout at the edge of the right-of-way or public utility easement
• Existing laterals: reuse of an existing lateral is allowed in some jurisdictions and not in others; ask the agency
• Elevation: check main depth against the lowest drained fixture early; a basement below the main needs a sump or ejector
• Permit: sewer connection permit and fees from the sewer authority; inspection before backfill
• Locates: call 811 before excavating; sewer lines are marked green

Relocation and disconnection

• Ownership: the agency usually owns the main and tap; the owner owns the lateral to the connection, and often the cleanout
• Who pays: the owner pays to move a private lateral; where private development forces the move of a public sewer, the developer generally pays; confirm with the agency
• Moving a lateral: a new connection follows the permit and inspection process for a new one
• Abandoning a lateral: one county requires the cap on an abandoned lateral downstream of the property line cleanout; another checklist requires a plug at the tee-wye with concrete poured around it
• Disconnect before demolition: cap or plug the lateral at the main or property line as the agency requires, and obtain inspection
• Separation: keep laterals away from water services as the plumbing code requires

Sources

• Delta Diablo: side sewer construction requirements, https://www.deltadiablo.org/files/cbc7b7beb/Side+Sewer+Construction+Requirements.pdf
• City of Evansville, IN: sewer lateral standard, https://www.evansvillegov.org/egov/documents/547f0a68_f253_f212_6834_7a8e0cc26f19.pdf
• San Mateo County, CA: sewer lateral standard, https://smcgov.org/media/46061/download
• North Carolina 811: safe digging guide, https://nc811.org/wp-content/uploads/2025/11/2025_safe_digging_guide-ENGLISH.pdf
• Minnesota Lawyer: developers pay the cost of relocating utility lines, https://minnlawyer.com/2025/06/23/minnesota-becomes-the-latest-state-to-require-developers-to-pay-the-cost-of-relocating-utility-lines/