ABS Foam Core in Trench with Pressurized System?

[Jer805]

I'm installing a sewage lift pump and 2" ABS pipe from my garage up to my house (and then out to the city sewer line). I'm having difficulty getting a clear answer to four questions:
1) is foam core ABS okay in a trench (18" deep in my area) or should I use solid core ABS,
2) same question given that it's part of a pressurized system (low pressure lift system),
3) when testing the installation how much pressure should I use (I assume more than a gravity waste line),
4) in my area you can run the water line right next to the sewer (if using modern materials, eg ABS), because it's a pressurized drain I've heard that a 12" space may be required between the water line and sewer pipe. Is extra space required in this case?

Thanks! I appreciate your help and love this forum!!!

 

[Reach4]

1) is foam core ABS okay in a trench (18" deep in my area) or should I use solid core ABS,

I doubt that you would find solid core ABS. Solid PVC is readily available as is PVC foamcore.

I don't know about your other questions.

 

[Sponsor]

 

[Jeff H Young]

I use sch 40 abs foam core for everything
the code states sewer and water may run in same trench providing the sewer piping is a material aprooved for use withen the building. sch 40 abs pipe is good.
10 fthead should be plenty . sewer outside building can get by filling it to the height of the lowest fixture or usualy slab height.
If you are pulling permits a consult with inspector a good idea

 

[Jer805]

I doubt that you would find solid core ABS. Solid PVC is readily available as is PVC foamcore.

I don't know about your other questions.

You're absolutely right. I finally got through to my distributor. Only foam core is available in CA. I could special order it but I'd have to buy some 3,000 feet. Solid core PVC may be the way to go. Thanks again!

 

[Jer805]

I use sch 40 abs foam core for everything
the code states sewer and water may run in same trench providing the sewer piping is a material aprooved for use withen the building. sch 40 abs pipe is good.
10 fthead should be plenty . sewer outside building can get by filling it to the height of the lowest fixture or usualy slab height.
If you are pulling permits a consult with inspector a good idea

Thanks. I just found out that the lift pump I'm considering only produces 10.8 PSI, not much at all. I have pulled a permit and just started a conversation with my inspector. Thanks.

 

[John Gayewski]

Foam core is not approved for burying.

We test at 1.5 times the operating pressure.

Water needs to be run above sewer 12" or 4'apart laterally.


These are the standards we use.

It looks like foam core abs can be used underground and is used interchangeably according to ASTM D2661 standards.

 

[Jeff H Young]

section 720.1 the first sentence explains that you can run sewer and water together if the correct pipe is run. don't need 12 inch separation not California. unless you are possibly in a stricter city perhaps bay area?
foamcore ABS is used in the majority of underground waste piping in California some people run thin wall cheap PVC for sewer, and some use sch 40 PVC that is robust but not as common as ABS.
I've never put more than a 10 foot head test on waste pipe. and used ABS cellular for pumping ask inspector to confirm if you want

 

[Jer805]

Foam core is not approved for burying.

We test at 1.5 times the operating pressure.

Water needs to be run above sewer 12" or 4'apart laterally.


These are the standards we use.

It looks like foam core abs can be used underground and is used interchangeably according to ASTM D2661 standards.

Thanks John. I appreciate you providing the ASTM standard!

 

[Jer805]

section 720.1 the first sentence explains that you can run sewer and water together if the correct pipe is run. don't need 12 inch separation not California. unless you are possibly in a stricter city perhaps bay area?
foamcore ABS is used in the majority of underground waste piping in California some people run thin wall cheap PVC for sewer, and some use sch 40 PVC that is robust but not as common as ABS.
I've never put more than a 10 foot head test on waste pipe. and used ABS cellular for pumping ask inspector to confirm if you want

I also understood that sewer and water could be side by side (in CA with correct pipe). With pressurized drains that doesn't hold true, the question is how much pressure do you need for it to be a "pressurized system." My guess is it's a lot more than the 10.8psi my sewage lift pump produces. Thanks

 

[John Gayewski]

A pressurized system, if I were interpreting it, would be any that doesn't rely on gravity alone to convey the contents of the pipe.

The standards in drainage just refer to an ejection pump. There is no threshold of pressure that makes it a pressurized system. This is how I see it.

 

[Jeff H Young]

A pressurized system, if I were interpreting it, would be any that doesn't rely on gravity alone to convey the contents of the pipe.

The standards in drainage just refer to an ejection pump. There is no threshold of pressure that makes it a pressurized system. This is how I see it.

Un sure the two statements sound conflicting. and my systems have been slight lifts 5 foot to 15 ft and used foam core abs maybe 10 times not a lot but unaware if not legal in california.

 

[John Gayewski]

I'm not sure of a conflict. If you have a gravity system it's gravity. If you have an ejector you have a pumped or "pressurized" system. That's how I interpret it.

 

[Jeff H Young]

I'm not sure of a conflict. If you have a gravity system it's gravity. If you have an ejector you have a pumped or "pressurized" system. That's how I interpret it.

I m unsure that an open pipe with waste pumped through it would be defined as a pressurized system by UPC code definition.
It very well could be though.