sewer vents and clean outs in front yard

[blazenut]

I was at a house that was once septic (in front yard) and has since been converted to city sewer. My question is this: the front yard is maybe 100 feet to the road. There is a clean out with cap about three feet from the foundation, another one with cap about half way through the yard, and then two next to each other about 15 feet from road, one has a vented cap and the other is capped (vented one closer to home-yard is slightly down hill). Why so many clean outs? And, does this vented pipe only serve the city sewer, or does this help serve the fixtures in the basement that are not vented. There is a washing machine, floor drain, toilet and sink in the corner of the basement where the main sewer line exits the home (the only vent for the home is on the other side of the basement below the kitchen). There have been no problems with the existing fixtures (no siphoned traps, or sewer gas smells). Im fairly certain of the the historical data since this was not for a client (close family member). Thanks

[John Dirks Jr]

Clogs usually happen where there are junctions and bends. Junctions and bends are usually closer to the house and closer to the street. The pipe in between is straight and less likely to have problems. Maybe that explains a set of clean outs near the house and another at the street.

[Jim Katen]

I was at a house that was once septic (in front yard) and has since been converted to city sewer. My question is this: the front yard is maybe 100 feet to the road. There is a clean out with cap about three feet from the foundation, another one with cap about half way through the yard, and then two next to each other about 15 feet from road, one has a vented cap and the other is capped (vented one closer to home-yard is slightly down hill). Why so many clean outs? And, does this vented pipe only serve the city sewer, or does this help serve the fixtures in the basement that are not vented. There is a washing machine, floor drain, toilet and sink in the corner of the basement where the main sewer line exits the home (the only vent for the home is on the other side of the basement below the kitchen). There have been no problems with the existing fixtures (no siphoned traps, or sewer gas smells). Im fairly certain of the the historical data since this was not for a client (close family member). Thanks

Couple of things to keep in mind. Maybe they apply and maybe they don't.

1: You're supposed to have a cleanout every 100 feet. If the distance between the house & the city sewer is more than 100 feet, there should be at least two cleanouts.

2: You're supposed to have a new cleanout whenever the pipe has turns that add up to more than 135 degrees. Maybe when they changed from septic to sewer, some bends were involved.

3: You'll sometimes see a pair of cleanouts next to each other when the plumber wants to provide for a snake to go either way. If the cleanout riser isn't too deep, you can use a two-way cleanout fitting. However, in houses with basements, the riser is so high that you really can't control which way the snake goes in a two-way fitting. So the plumber instead installs two wyes (or combos) facing opposite directions. These make it necessary to have two caps right next to each other.

4: On the east coast, it used to be common to have a whole house trap. Those sometimes had vents near ground level. I'm not sure how common these are anymore. (Moved away 30 years ago.)They always seemed like a dumb idea to me. They were in the basment though, not out by the street. I don't know why you'd need a vented cap out near the street.

5: A sewer scope can answer all of your questions.

- Jim Katen, Oregon

[Bill Kibbel]

In addition to what Jim said:

There are still cities and towns that require whole house traps. I've had plumbers insist they be torn out immediately after the municipal inspections are completed.

Whole house traps were very commonly recommended by septic system installers. A handful still do.

I've found that typically buildings built before 1940 have the traps installed within the footprint. After WWII, they're most often in the yard and have a vent next to a clean-out. Some areas have the whole house trap near the street - they were called "curb traps".

[blazenut]

Thanks guys, great info as always.

[John Kogel]

Something nobody's mentioned yet - some of those cleanouts could be for the perimeter/storm drain system. Around here and I imagine in most places, they are kept separate from the sewer lines. Sometimes there are double pipe systems, perimeter and downspouts are kept separate, so you see even more cleanouts.

Some cleanouts could be left over from the septic drain field system. A vent out in the yard won't help the basement plumbing very well. They may have tied all vents into the one you saw at the kitchen.

It's hard to tell from here. []

[robert1966]

Great information and comments as always. I was under the impression that some sewage systems based on the types of some ordinaces require clean outs every so many feet of linear run. I have also seen where an additional clean out was added to a lon run in a line after a clog occurred in the area. The additional clean out was added while the work was being performed to make the next clean out jub easier.