Strange very green lump of grass in yard....

[Fimbresfactor]

Can anyone tell me if the lump in the front of my apartment is really from a sprinkler? This place has had issues with plumping as far as clogged drains. Its right next to a clean out area. I am worried that its a leak in the sewer line.. I'm no plumber so that's why I am asking.

 

[Twowaxhack]

Maybe the crap that overflowed out of the cleanout fertilized the grass right there.

Crap = nitrogen = green grass