PVC Pipe, Encrustation Classification (PACP)

[1Sponge]

I am reviewing some CCTV inspection data for a PVC pipe. The inspector has classified some of the deposits attached to the PVC pipe wall as "encrustations". According to the PACP manual the term “encrustation” refers to “deposits left by the evaporation of infiltrating groundwater containing dissolved salts”. I’ve only seen these types of encrustations in concrete pipe. Can they also be present in PVC pipe? I can see how salts might come in through a concrete pipe wall but how would they make their way in through a PVC pipe wall? In my experience PVC doesn’t tend to gradually wear away like concrete, it tends to crack or fail completely. Can anybody out there offer any insight on this?
Also, I have attached a screen shot of a defect that was coded as an encrustation. I would code this defect as deposits attached unknown (DAZ).

 

[SteveWag]

I have looked at a few miles of TV’d gravity sewer pipe, green, just like yours. The spots/smears are a result of staining during high flow events (turbulent conditions). Any deposits are grease or other stuff found in sewage. I would wager that everything but the stains could be removed with a rag or brush.
Steve

 

[Fodder]

the correct codeing would be two seprate codes. (dags, deposits attached grease) one for 5 and one for 7. A high pressure jetter would remove the grease, however the amount of time for this build up to become a problem can be measured in years with the current flow.

 

[1Sponge]

Thanks for the feedback Stevewag and Fodder. Can either of you speak to wether or not the "encrustation" classification (as defined in my original post)can apply to PVC pipe?

 

[Fodder]

no your first post would be correct. pvc pipe would fail befor it would allow ground water to leach through the wall.