Still think you may have a cracked jacket and your leaching outside water, That was my well guys theory, They have a camera they send down the pipe to look for that, If this disinfecting doesn't last thats where i would be looking next.
Accidents galore up here this morning, Section of the tpke was closed earlier for a tractor trailer and several cars off the road heading south in Falmouth.
Don't even think twice on this, Its common ground every winter, Better when its the track on my sled doing it though, But a nice reminder of what we take for granted up here.............