when I do laundry a fowl smell is coming from bathroom ,how and what can I do?I have septic system?

This is most likely caused by improper venting of your drainage system. What happens is that your drainage system becomes depressurized when a fixture drains and can suck the water out of the p trap in your sink, shower or floor drain, (not your toilet though as someone mentioned).

Easiest fix for this problem is to install an air admittance valve, (or cheater vent as some plumbers call them), on your drain handling your washing machine.

You could buy one of these vents at your local plumbing supply store and they are failry simple to intall.

Good luck

1. make sure that your toilet has been flushed and that there is water in the trap.

2. Make sure that your bath has water in the trap as well as your sink. You might want to fill the bath and the sink and leave water in them.

I think, however, that your system is not venting out of a pipe on the roof and the best way to do that is to buy a "snake" and get on the roof with that and a water hose and run the snake down, making sure that it twists as it goes and once it hits bottom, put some water into it to carry what you have loosened up into the septic line or the sewer line.

If you have a lot of trees, especially those that drop nuts or sweet gum balls, you can but a little "hat" to go over the vent, elevated 6-8 inches or so but certainly not stopping the vent pipe up.

If that is not the case, you will have to open an inspection part of the main sewer line, going from just below the toilet in the area of the bathroom where it stinks, and run it all the way to the septic or sewer.

If this is too much, call a plumber.

It does sound like you may have a blocked vent as Biker suggests, however before I called the plumber, I would get up on the roof and see if it isn't something simple like a birds nest causing this blockage! Also be aware there are water traps in all your plumbing fixture drains to prevent sewer fumes from entering your house, perhaps the bathroom sink has a leak at the water trap and is allowing the water in the trap to drain out? I would do these checks first, because here in Miami, FL where I live it'll cost $50 just to have a plumber come look, and that's on a week day!

you may need your tank pumped... When it gets full gases tend to enter the house when the toilet if flushed or laundry is done... Find the cover open in it if see sludge close to the top have it pumped.. only about a $100. if you live in a fairly rural area I bet there is companies that specialize in septic care ( not a plumber)

Located under sewage or septic in the phone book. Tanks need pumped every so often depending on your faimly size and size of your tank... mine is old and has to pumped every year maybe 2.... Also you could try buying the septic treatment in the hardware department after you hav it pumped it helps with the whole thing keeping bacteria which are good at the right level in the tank to break down waste

Also, if you have had high winds recently, they can force the water from a trap thus leaving it dry and let gasses into the living space. Run water down each sink, etc for 10 seconds to make sure all traps are wet.

I would call a plumber on that one if you have had the septic tank cleaned out on a regular basis. something is blocking the venting of those gasses.

Yes most like'ly it is your vent.Use RID-X in it once in a while help's some i hear.Get your tank pumped out every once in awhile.I have the same problem and can't get rid of it and i'm on city sewer.

SOUND LIKE SOMEONE FAILED TO INSTALL A P TRAP SHICH HOLD WATER IN IT TO STOP THE BACK FLOW OF SEWER GAS AND A VENT PIPE CONNECTION TOWARD THE ROOF. CHECK THAT OUT