You have assumed the slab is actually level.
Borrow or rent a laser level (self leveling prefered) and take the measurements again.
Why can't the kitchen sink end be raised? Is it already against the bottom of the joists (or in bored holes)?
If it is against the bottom of the joists time to bore holes (folowing the rules and not just boring at random).
If it is already in bored oles you may need to check if you can sister the joists and then bore higher up.

Thanks for responding Brickeyee.

I shot the slab with a transit to check the 2 ends of the run. They are level within 1/16". The drainline at the kitchen end goes on to catch the washer in the laundry room which is on a slab at grade level. From the kitchen sink the drainline runs through the rim joist and into the slab, exiting at the washer. It appears the the slab is 4" thick which I assume would prevent me from getting any additional height, even if I break out the slab, without raising the level of the entire floor.

This drain has been working like this for 14 years but I'm sure there was a regular problem with blockages that required snaking the line. Realistically, with gravity working as it does, if I replace the sagging pipe and make sure I don't have any negative fall, could this drain be expected to perform for a reasonable period between clogs? Does anyone have any experience with 1/16" per foot fall over 60 feet? Half of that 60 feet is servicing the kitchen sink, washer, dishwasher and disposer. I don't plan on using the disposer because I don't think it's good for the septic, but the dishwasher will send a limited amount of debris down the drain.

I have never seen a drain with less then 1/8" per foot and don't know how this one will operate, especially with the solids. As drastic as it seems, if the only way to have a trouble free DWV system is to lower the septic tank, I will do it. If however, someone has another workable solution, I'm all ears.

The line is in the basement floor slab?
Move it into a small soffit in the basement ceiling.

No, the line is hung from the floor joists in the basement - 87" off the slab at the kitchen sink end, 82" off the slab at the penetration to the septic tank. The end of the line at the washer is in a slab at grade level above and beyond the basement. Still need someone to comment on the viability of a 60 foot drainline with only 1/16" per foot total fall. Can this line work, or will the solids have trouble moving through.

Just curious does it run parallel to the joists or perpendicular?
What I think will happen is stuff will begin to settle, then more stuff will stick to that, eventually blocking the line. But I think it would be in the order of 6 mos to year or better. The biggest two problems will stem from soap and grease buildup.

My advice would be to have a pro look at and see what they have to say.

You might want to investigate the cost of a pump solution and use that as a basis in negotiating a compromise.

If you are tight against the joists at the kitchen end at at the septic line level at the far and a pit & pump might be a decent option.
You can also check into moving up into the joists and boring.
It is a real PITA after the fact since short sections of pipe must be used in many cases.
A 1/16 inch fall WILL cause problems long term, particularly if you have a garbage disposal.

The drain line changes direction 3 times in the 60 feet, so it runs parallel and perpendicular to the joists depending on the section you are looking at. At the beginning of the line it is running parallel to the joists but is as high as it can go when it penetrates the rim joist and runs into the laundry room slab. I've considered using a grinder pump to address the problem but view this solution as trading one maintenance headache for another. Additionally you lose all drainage capability during a power failure unless a much larger generator is utilized for backup power to accommodate the relatively large load most grinder pumps impose on the system.

In respect to seeking the advise of a "Pro", remember, it was a pro who caused this problem in the first place. In my experience, it is very difficult to find a competent tradesmen who not only can think out of the box, but can implement his craft at a high workmanlike level. I hate to paint with a broad brush, but finding a plumber who is interested in doing an excellent job is very difficult. I'm not saying they are not out there, but they are definitely in the minority. I can't risk hiring someone who may make the problem worse.

The above statements may make some mad, but anyone who has built a house using subcontractors will at least understand the problem with substandard work. This house for example, was built by a well respected builder as a custom home designed by an architect. It was not cheap by any means. The house looks good from the street but when you look closer, poor workmanship is displayed in many areas. The most obvious, in addition to the above problem, is the insulation detailing - no insulation at all in the exterior basement walls - seems like a no brainer when going to the trouble of finishing a basement, not a stitch of insulation in the joist pockets at the rim joist - noticeable air movement, the electrician installed all the switch and outlet boxes throughout the house too far beyond the stud face so the cover plates cannot rest on the drywall but have a 1/4 inch gap all the way around, not to mention that there are not two boxes set the same height from the floor, poor exterior flashing details especially at the tops of the windows - no flashing at all. The list goes on. These are things that are caused by a "good enough" attitude that is too prevalent in the trades today.

The unfortunate part about this situation is that this house is the best one I found after an exhaustive search that covered no less than 75 homes up to the 400,000.00 range. I bought this home because the price was right and I knew that most of the issues, I could repair myself over the course of the next few years. I guess my point is that there are a lot of self proclaimed Pros out there, but very few who actually are. Being a licensed contractor is no more an indicator of a competent qualified workman than a drivers license is an indicator of a good driver. Most anyone can get one.

Sorry for the rant, but I guess this whole plumbing situation has me a little aggravated, mostly with myself for not catching it. I appreciate the input from this board and can assure you all that, whatever repair needs to be done to resolve this problem, it will be done right. To any contractors that are competent and take pride in doing a good job, keep up the good work. Sometimes it seems that nobody notices those small details that make your work stand out from the rest of the "average" guys but I can assure you that there are people out there that do appreciate a true craftsmen and are willing to pay for that talent.

In case anyone is wondering, I work in the trades myself. I make my living repairing commercial and residential standby power generator systems. I could tell you stories about systems installed by licensed electricians that would make your hair stand on end. I make a good living repairing these installations daily. But that is the subject for another thread.

Thanks again for the responses. I believe my original thinking has been confirmed - 1/16" per foot of fall is just not gonna get it.