Maintenance for the week of October 5:
• [IN PROGRESS] ESO Store and Account System for maintenance – October 8, 8:00AM EDT (12:00 UTC) – 12:00PM EDT (16:00 UTC)
I don't know why from a lore perspective but from a game perspective they say that Tel Var Stones will only drop in areas which are flagged for PVP to ensure that there is still always some risk of other players even if it is in your Alliance Sewers.