He doesn't mention "regular conduit" anywhere. Anything he brings up seems to be about the subject of the thread, water pipes, and bringing up PVC glue means he's talking about PVC pipes.
He says
On October 6, 2017 at 18:01, Grasshopper said...
...I noticed the other day that the subs had, at least in one spot, used water conduit to run fiber through....
Actually, we should have stopped him right here to point out that there's no such thing as "water conduit" and he should figure out what it's actually called so we'll all KNOW what's being discussed.
I get dinged here for insisting on accurate terms, then we have a discussion like this where there's lots of confusion......
I also pointed out to my boss that the subs hadn't used a drop of pvc glue on any of their joints. Apparently my boss talked to them about that because they're now using pvc glue, as I ran into it today. But, even if they go back (they say they're going to) and glue their joints...that still leaves the ones that are under ground and I highly doubt they'll dig it all up again.
So he's saying he doubts' they'll dig up the pipes that the fiber runs in, to add PVC glue to it... which is to say those pipes are plastic.