[prhs]

Hi. I have a detached garage. It is about 30 ft from the my house which is another 30 ft or so from the tie in to the municipal sewer line. The house is a split level type house and the downstairs of the house is tied into the sewer line through a sewage ejector pump (which has been working well for over 40 years). The proposed bathroom in the garage is one the second floor of the garage and well above the sewer line by about 5 feet. However, I cannot have a waste line running from the garage to the sewer line in anything like a straight line with the required slope as it would be going through air and would require crazy insulation as well as being immensely unsightly and probably quite illegal (imagine a tree limb fell on it!). As I see it, I would need to drop the waste line vertically at the edge of the garage (which is heated and insulated so there's no worry about freezing, there), then dig a trench with the usual slope, which will put the termination of the waste below the entrance of the ejector pump that I have now. What I want to know is can I have the waste run up hill at a gradual slope (say 5 degrees or so) or almost 60 feet if I place another ejection pump in the garage. I have seen a saw tooth profile method (in japan!) of running uphill after a pump. The long runs slope at the usual shallow downward slope followed by a sharp and very short upward slope followed again by a downward slope. This allows sedimentation to only occur at the point of upward / downward transitions. I cannot tell if this is clear to readers as I've been thinking about it for a while and probably what's stuck in my head is not getting out on this. BTW, I am clearly not a plumber, I am a physicist. Please help. I am in Massachusetts.
Thanks!

[massplumber2008]

Well, to start, because we are talking about water that is moving in the "properly pitched", drain pipes freezing really isn't an issue, but it certainly sounds like it would be "unsightly"!

Next, when you say, "which will put the termination of the waste below the entrance of the ejector pump" are you talking about the actual inlet piping to the ejector PIT (4 feet below the top of the pit... usually underground), or are you talking about connecting into the top of the tank (illegal)?

Once you clarify that we can chat a bit more.

Mark/Boston

[prhs]

Well, to start, because we are talking about water that is moving in the "properly pitched", drain pipes freezing really isn't an issue, but it certainly sounds like it would be "unsightly"!

Next, when you say, "which will put the termination of the waste below the entrance of the ejector pump" are you talking about the actual inlet piping to the ejector PIT (4 feet below the top of the pit... usually underground), or are you talking about connecting into the top of the tank (illegal)?

Once you clarify that we can chat a bit more.

Mark/Boston

Hi Mark,
Thanks a lot for answering.
Yes, the termination would be somewhere around the bottom of the pit, which would be fine, EXCEPT that the pit is enveloped in concrete and I really, really don't want to bust into the slab to do this.

But, that brings up a very interesting question. Why is it illegal to connect to the top of the tank? The toilet and the lav sink both go to the bottom. The waste from the washing machine, though goes right into the vent line and, presumably, falls directly down to the bottom of the tank. Why is that bad?

I read, somewhere, that although it is preferable to have the waste line from a macerator or ejector pump composed of a vertical rise and horizontal (with appropriate downward slope) it is acceptable (but not preferred) to have an upward sloping line from it. Is this true? Or would a saw tooth (vertical element, code type slope horizontal run, vertical element, code type slope horizontal run, etc.) run be better (if it's even acceptable!)?

Thanks! Peter