Can someone please identify the purpose of this covered plastic pipe in my front yard. I can provide further details as necessary. I thought it was a drain clean-out, but the plumber disagreed. In the back yard, there is a clean-out for the combined sewer/storm line. Photos attached with cap on/off.
The cap is called a "popup emitter" and is used to cap a drain line. When there is water pressure the center part "pops" up and allows the water to flow.
Perhaps it's from a downspout or a sump pump. It looks as though it may be clogged up.
Get your garden hose and run water through any water drain lines in your back yard. If your downspouts go into buried drain lines, your basement sump, etc. Then watch and see if water comes out of this drain end.
One other option is that you have a buried french drain back there that runs to this drain end. In that case, the garden hose trick wouldn't help.
Hard to tell from the pic, but you can put a shop vac on it and try to suck out as much of the debris and standing water as possible. See if it fills back up by itself, which in that case may suggest it's from the water table under ground (french drain).
Thanks for all the responses. I'm fairly certain it is indeed a cleanout pipe for downspout drain line(s). There are two downspouts in the front area of the property--one on the side of the house (same side) but the drain pipe bends to the front, and another downspout in the front (that was since abandoned/covered at ground level by previous owner). I believe possibly both pipes connect with a Y-connection and then drain at the curb. There is an opening at the curb on my side of the property line which is roughly in line following the downspouts and cleanout pipe.
The downspouts at the rear of the house seem to feed into the sewer/storm line. The plumber who was clearing my rear storm/sewer line thought it had to do with irrigation/sprinklers (but never pulled cap).