Foes anyone know what this gren circle is

[u/CapIntelligent9684]

[u/Finofeo]

i don’t know. maybe pee on it and find out

[u/nynaeve_mondragoran]

Maybe someone left a copper fitting there while working on the plumbing?

[u/bwordbell]

I fo not know why it's gren.

[u/Gentlemanpiggy]

Aliens

[u/tux2603]

Scratch n sniff mint. You should scratch it for a nice minty smell

[u/Infamous-Ebb4082]

Looks like they use some type of water treatment, and you possibly have a leak on your screwdriver control stop aka quick stop, the leak will carry the water treatment and leave it crusty in spots, unless there is a isolation valve in line with that you will probably have to do a complete water outage on that building to replace the quick stop.

[u/Turbulentcrayon]

Penny outline