The cast iron cellar drain that services 1st & 2nd floor kitchen sinks, cellar laundry utility tub and cellar clothes washer has deteriorated and digging up the cement floor to replace it and hope there are no problems tying into the soil pipe could result in more problems than solutions.


There is enough depth in the 1st floor joists to run an overhead horizontal drain pipe from the kitchen drain pipe to the soil pipe at 1/4" per foot with some room to spare.

1. Can I connect the clothes washer via a trap into the proposed horizontal line using only the clothes washer pump to pump its gray water up 7 ft or should I discharge it into a collection tank/"sewage" pump unit?

2. I am assuming I can run the grey water from the collection tank for the set tub (and possibly clothes washer) into the proposed horizontal run via a trap

3. Venting the collection tank.... The 2nd floor kitchen waste pipe is also the wet vent for the 1st floor kitchen sink (2" pipe). Can I vent the cellar collection tank into this pipe such that the pipe below the 1st floor kitchen sink is now a wet vent for the collection tank OR do I need to vent the collection tank separately up above the 2nd floor kitchen sink into the dry vent that goes through the roof? ( I suspect the latter)

Thanks for your time

1. Can I connect the clothes washer via a trap into the proposed horizontal line using only the clothes washer pump to pump its gray water up 7 ft or should I discharge it into a collection tank/"sewage" pump unit?
No! Two things are questionable. Not all washer pumps will pump a 7 foot head and you wouldn't have room for a stand pipe out of the trap.

2. I am assuming I can run the grey water from the collection tank for the set tub (and possibly clothes washer) into the proposed horizontal run via a trap.
Do you even have a holding tank and ejector pump or is it a projected project? Since the tank is a sealed unit and the pump will connect directly to the sewer system no trap is needed.

3. Venting the collection tank... The 2nd floor kitchen waste pipe is also the wet vent for the 1st floor kitchen sink (2" pipe). Can I vent the cellar collection tank into this pipe such that the pipe below the 1st floor kitchen sink is now a wet vent for the collection tank OR do I need to vent the collection tank separately up above the 2nd floor kitchen sink into the dry vent that goes through the roof? ( I suspect the latter)

You may not do either. The holding tank must have its very own dedicated vent out the roof.
Sorry to rain on your parade, Tom

speedball1 = thank you for your very prompt reply.

The answer to Item 1 doesn't surprise me, I had doubts about the ability of the washer pump to push anything much more than a foot above its top

#2 - "Do you even have a holding tank and ejector pump or is it a projected project? Since the tank is a sealed unit and the pump will connect directly to the sewer system no trap is needed."

no I don't have a holding tank or pump yet; the whole purpose of these questions was to find a solution to digging up the cellar floor, replacing the deteriorated iron waste pipe that serviced the previously mentioned kitchen sinks and cellar laundry tub and clothes washer, and especially not having to tie into what remains of the main cast iron soil pipe that is presently in a poured concrete wall

#3 and summary. What would you propose? If I read your replies and have asked and answered the questions correctly, it looks like I have 2 choices:
(1) dig up the floor to replace the existing lines
or
(2) replace the kitchen drain with a (cellar) overhead pipe into which I directly tie the proposed holding tank and ejector pump that would service the basement laundry sink (which would keep its trap) and clothes washer and a vent for the tank that would run from the tank in the cellar all the way to the roof. If I elected option #2, any suggestions on brands for the tank and pump? Reliability is top consideration, my thoughts were with Zoeller?

If it were my problem I'd bite the bullet and replace the cast iron lines under the cememt with PVC. This would bend up cheaper and more serviceable in the long run. Gravity is cheaper and more dependable then mechanical units any day and won't have to be replaced as often. Let me know your thoughts. Regards, Tom

Thanks for your sensible reply. My thoughts at this stage are to go ahead with the kitchen drain pipe running between the floor joists over to the soil pipe just to get the sinks operational and then do the floor work for the washer and laundry set tub in the cellar. Once that's done connect the kitchen drain/wet vent back into the cellar drain as they are all in the same vertical line thus restoring it to the original configuration

Thanks again for your knowledge and sensible participation on this forum