Water main through abandoned septic drainfield

[Ryan J]

Hi all, does anyone have resources that would be useful in designing (or not designing) a water main through an abandoned septic drain field?

I'm currently scoping a project in WA that is supposed to loop a water main, but the existing dead end is locked in by buildings and an abandoned septic drain field. The field was abandoned sometime before 1998. None of the usual reference documents contain any standards on running a main through an abandoned drain field (although they do require a minimum of 10' of separation from an active one, which is not feasible on this project).

Any tips, backed by some references, would be very helpful!

TIA

 

[1503-44]

Isn't it just fertiliser by now?

--Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."

 

[LittleInch]

What's the issue here?

Install sealed/welded pipe and you're OK. You can get special PE pipe with a thin metal band to prevent any seepage of chemicals which could taint the taste.
Seems to be called barrier pipe
E.g.

https://www.cotterillcivils.co.uk/p...organic&utm_campaign=sag_organic&gad_source=1

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[1503-44]

If you are using welded pip, no issue that I know of.
If you are using pushed-in joints, switch to welded pipe in the septic field.
Do you have an analysis of the soil?

--Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."

 

[HTURKAK]

You did not supply a lot of info. here. The septic area abandoned more than 25 yrs. Do you have soil analysis ? What is the GWL , slope and depth of PL ? What is dia and service pressure ?

I would consider PE encased DI at first .

Pls look
- AWWA C105 standard [for] polyethylene encasement for ductile-iron pipe
- AWWA M41 Ductile-Iron Pipe and Fittings.

...

He is like a man building a house, who dug deep and laid the foundation on the rock. And when the flood arose, the stream beat vehemently against that house, and could not shake it, for it was founded on the rock..

Luke 6:48

 

[bimr]

The following Standards can also be helpful references when addressing permeation concerns:
ANSI/AWWA Standards C900 through C950 state that if a water main must pass through an area of gross contamination, the manufacturer should be consulted regarding the permeation of pipe walls and joint fittings prior to selecting the material. The Standards also note that research has documented that pipe materials such as polyethylene, polybutylene, polyvinyl chloride, and asbestos cement, and elastomers, may be subject to permeation by lower molecular weight organic solvents or petroleum or pesticide products.

Ductile Iron Pipe