Common Sewer Line Problems in Older Philadelphia Homes

Much of Philadelphia’s housing is old: brick rowhomes from the 1800s and early 1900s, twins and stone houses in the streetcar suburbs, and post-war rows in the Northeast. The sewer line under each one is usually as old as the house, or has been patched a few times since. These are the problems that come up most, and what the City’s own documents say about them.

1. You own the whole line, all the way to the main

PWD’s Sewer Connection Manual puts it in one sentence: “The property owner owns, and shall maintain and repair, the property’s entire drainage system and the sewer connection.” That includes the house main drain, the curb trap, the vent pipe and its cover (the fresh air inlet), the lateral under the sidewalk and street, and the slant or tap where the lateral joins the main. The City’s Revenue Department notes this holds “even if the broken pipe is outside your building, like under the sidewalk or roadway.” PWD maintains the sewer main itself. See which pipes are yours.

2. What your lateral is probably made of

The pipe material says a lot about how a lateral fails. A camera inspection usually shows it.

Material	Where you find it	How it tends to fail
Terra cotta / vitrified clay	TreePhilly (Philadelphia Parks & Recreation) says older homes built before World War II may have terra cotta laterals.	The same source calls them “more prone to cracking and breaking.” Joints between short clay sections can open up and let roots in.
Cast iron	The same TreePhilly fact sheet says Philadelphia house laterals are made from cast iron.	It says cast iron laterals usually last 60–70 years, given Philadelphia’s freeze-thaw cycles, traffic loads in the street, the fill under sidewalks and streets, and electrical currents in the ground. Old cast iron can rust, crack or scale up inside.
Bituminous fiber (“Orangeburg”)	Used widely in the U.S. from the 1940s to the 1970s, according to the Minnesota chapter of the American Public Works Association, so mostly in post-war houses.	Made of wood fiber and coal tar pitch, it was advertised to last about 50 years. APWA notes it was once thought root-proof, but once moisture gets into the walls, roots find their way in. Tell your plumber if you suspect it.

For new work, PWD’s Sewer Connection Manual lists ductile or cast iron, reinforced concrete and vitrified clay as lateral materials, and says plastic pipe, including ABS and PVC, “shall not be used for lateral construction in the cartway” (the street). Portions outside the street follow the Philadelphia Plumbing Code. Your plumber handles this, but it explains why quotes specify the pipe material.

3. Tree roots: usually a symptom, not the cause

Roots are one of the most common things a drain cleaner pulls out of an old Philadelphia lateral, and it is natural to blame the street tree. Philadelphia Parks & Recreation says roots “can find their way into a sewer lateral, but normally that occurs only after the lateral has begun to break down as a result of age, settlement, or other factors.” It notes that most of a street tree’s roots are in the top 12–24 inches of soil, while a lateral under the sidewalk is on average 6–7 feet down.

In other words, roots in your line usually mean the pipe already has a crack or an open joint that is leaking water into the soil. Cutting the roots clears the line for a while. The lasting fix is repairing, lining or replacing the damaged section. A few related points from the City:

Parks & Recreation prunes street trees and removes dead or hazardous ones, but says it does not remove living, healthy trees and cannot work on private property.
If a contractor needs to work on a street tree, Parks & Recreation requires a tree work permit.
Street tree problems such as dead limbs are a separate request from your sewer repair.

4. Curb traps and fresh air inlets

Many older Philadelphia homes have a curb trap, which PWD describes as the J-shaped pipe connecting the house drain to the lateral, with a vent pipe (fresh air inlet) and a vent cover nearby, often at the front of the house. Traps hold water to keep sewer gas out, and like any trap they can catch debris and clog. A broken or missing vent cover can let debris into the line. Because the curb trap is part of the owner’s plumbing, PWD can include it in a Notice of Defect, and the HELP loan specifically covers curb trap repair.

5. Wipes and grease make old pipes worse

An old lateral with rough joints or a slight sag catches whatever goes down the drain. PWD says plumbers and its inspectors find customer-owned laterals “jammed with wipes,” that wipes sold as flushable often don’t back up that claim, and that lateral repairs “can cost you upwards of tens of thousands of dollars.” It also warns that cooking grease hardens in pipes, often in the lateral, and can lead to a Notice of Defect if a clog causes problems on the block. PWD’s advice: flush only toilet paper, and put cooled grease in a can in the trash.

6. Backups when it rains

The oldest parts of the city are mostly served by combined sewers, which carry sewage and stormwater in one pipe. PWD says combined sewers cover about 60% of Philadelphia. In very heavy rain they can fill up and push water back toward basements. That is different from a broken lateral, and PWD’s free Basement Backup Protection Program may install a backwater valve. The catch: your lateral has to be in good condition first. See sewer backups.

7. Shared and private sewer lines

Most Philadelphia homes connect directly to a public sewer, but not all. PWD’s Customer Guide says some homes or developments have privately owned systems, that “all private water mains and sewer pipes are the shared responsibility of the property owners who are connected to them,” and that buyers should confirm a home does not share a private sewer lateral with other properties. If your home is on a court or alley, it is worth checking where your line actually runs. PWD’s HELP loan covers repairs to a private sewer connection that require reversing the drainage direction to connect to a public sewer.

What to do about it

Get a camera inspection if you have repeat clogs, roots, a backup, or you are buying. Keep the video.
Match the fix to the footage. One bad joint may need only a spot repair. A lateral that is cracked or root-filled along its length may be a candidate for trenchless lining or bursting or a full replacement.
Use a licensed plumber who pulls permits. How to check.
Look into help with the cost: the HELP loan after a Notice of Defect, or PHDC’s free repair program for eligible owners. Options.

Want a second opinion or a quote? We can connect you with an independent, licensed Philadelphia plumber. Request a quote

Local detail: sewer issues by neighborhood.

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Sources

Checked October 24, 2026. City programs and prices change; confirm with the source before you rely on them.

Common sewer line problems in older Philadelphia homes