[kbhome]

how do you clean the lateral sewer drain pipe?I am getting this horrible sewer smell in certain bathrooms of my home after i use my high effciency washer. the lateral sewer pipe in my yard is for some reason uncapped and I think something may have fallen in the hole and clogged it, contributing to the smell

 

[Mike Swearingen]

Each fixture drain has a trap to prevent sewer gas from entering the home. Each drain has to be vented after the trap. These vents are then vented to the outside through the roof.
When the roof vents get clogged, or partially clogged, with birdnests, leaves, debris, etc., they do not allow the drains to function properly and it creates a siphon of the water from the nearest trap for a "vent" when water drains through the lines, such as your washer.
Go up (or have someone else do it) on the roof and clean out all debris that can be reached by hand from the vent pipes. Then snake the vents with a heavy duty plumber's snake to break up the debris, if any, if necessary. Then flush the vents down with a water hose sprayer.
It should all just flow right out into the sewer and clear your vents, solving your problem. Sometimes just flushing it down with a water hose will do it.
Good Luck!
Mike

 

[JDC]

In addition to what Mike said, I noticed that you posted that you have a high efficient washing machine. These machines dump alot of water in a very short amount of time. Here in Ohio we've have trouble with these machines dumping so much water so quickly that the vents get blocked with water and traps nearby get sucked dry. Our code was changed to increase pipe sizing for washer boxes/standpipes serving washing machines. Does your washer dump into a box or standpipe of does it dump into a laundry tub?

All this being said, I would definitely give what Mike suggested a try. That just might be the culprit.