Basement sink filling with water and non-draining ( winter, no water use, house not used) why ???

[Daveycat712]

My dad has dementia so we look after him in another house . His house has zero toilet use, zero washing machine use, and zero tap/sink use. Once a week i water his plants and there is no water down the sink ever . It is winter, a very cold January, and all of a sudden his basement sink is filling with dirty, sandy water that will not drain ( tried plunger).
A few days later the city ripped up the street in front and it looked like they were putting in a 6" - 8" diameter piece of pipe
6' - 8' long in the water filled hole they were digging. Right after that the sink mysteriously drained , leaving a big mess of dirt/sand in the sink. 3 days later the sink filled with water again that will not drain ( from where ???) . And more water is coming in the sink.
What the heck is going on ?
Frozen sewer? City f-up ?
Where to go, what to do from here ?
Help please.
Thank-you.
David

 

[Tuttles Revenge]

It certainly sounds like a clogged sewer if the work they did cleared it. But maybe they forgot to hook everything up? Or there is more of a clog somewhere downstream. Sand in what is coming back sounds like a collapsed drain to me too.

I've been in North Bay during January... its COLD up there!!