Air admittance valve in the yard?

[68malibu383]

I inspected a slab home built in 2019 today and there was an air admittance valve in the yard against the foundation. I've not seen everything but have been inspecting for nearly 15 years and this is a first. Is this allowed? See photo.

 

[Tuttles Revenge]

Legal? Dunno about in Denver. Maybe depends on what its connected to.

https://ipscorp.com/pdf/studor/Studor_Technical_Manual.pdf

 

[Sponsor]

 

[Reach4]

Just curious -- septic or sewer?

 

[68malibu383]

Just curious -- septic or sewer?

Its listed as city sewer. This is in a tight neighborhood with small yards. I've inspected a bunch of these houses and this one had one more odd item: a septic alarm in the garage.