My washing machine is located in the kitchen. My house is not on a concrete slab, it is raised slightly off the ground, elevated enough for a man to belly crawl underneath. Anyway, underneath the house, under where my kitchen sink is located is what has been called an "access" pipe. It used to have a cap on it and while the cap was on, the washing machine would back up into the sinks. With the cap off, the washing machine does not back up into the sinks, however it does drain freely underneath the house, causing another problem. I've had someone come take a look and was told that there was a severe blockage in a section of the plumbing under the house and that the section that is blocked is also cast iron and needs to be replaced with pvc pipe. I do not know the size of the blockage. I have also been told that there is not "vent on the roof". I have no idea what this means.
The water draining under the house is creating a breeding ground for bacteria and mold, I'm sure. Not to mention attracting bugs and vermin. I would like any advice and/or estimations of possible cost if this at all possible. My landlord doesn't seem to think this is a serious problem and has only had "shade tree" plumber types to come and "take a look" at the situation.
Thank you in advance for any help.

You have a blocked drain. Call a local drain cleaning contractor from your phone book. They will insert snake where that "cap" is and remove the clog. Yes, it is health hazard to have sewage draining under the house. Take care of it now. It is not a big problem since your toilets are draining OK. Let us know how it went. Back to you. Milo

I'd tell your landlord that you don't want to be a jerk, but this is more serious than he thinks and he needs to resolve it! I am sure the local Board of Health and/or plumbing inspector would agree here!

Suggest that he/she call a licensed plumber that can replace the pipe and snake the drain... usually cheaper than a drain company... ;)

We cannot begin to estimate costs on this. The landlord should call a couple plumbers and get estimates for cost!

Good luck!

Mark