frozen greywater pipe

It's extremely cold here in southern Ontario. My greywater froze in the pipe a few nights ago. I have a dam that I always close before I go to bed in the evening in the winter time. I should have closed it early that evening. Now it's frozen. Although it's interesting trying to live with just using a dishpan in the sink and dumping the water outside, it's a pain in the you-know-what, plus I can't do laundry or have a bath. Thank heavens my son lives nearby.

The pipe (black, just under 2" diameter -- ABS?) goes from inside the house in the basement about 25 feet underground to the greywater pond. I've tried pouring boiling water over the part that sticks out and banging it with a hammer (that's always worked before, but this weather is colder than I've ever experienced). Only the bit of ice in that part came out. Next I tried sucking out the 'wet' water in the basement part of the pipe using my shop vac. The idea was to pour RV antifreeze in so it would eventually melt the ice. The pipe is on a slight downwards slope so only a very small amount of water came out and I could get less than a cup of antifreeze in, not near enough.

Any other ideas? I have very little money so can't buy some expensive piece of equipment even if there is something like that. If I can't melt the ice, I'll be living like a pioneer until at least May as far as water use is concerned.

One time my brother had a frozen pipe on his farm. He stuck a wire in each end of the blockage, connected the wires to his welder, and turned it on. The arc through the ice melted the blockage. I make no claims that it was a good idea. What I have done is to wrap all vulnerable pipes with heat tape and insulation. Another thing you could try is to just put another drain pipe thru the wall and let it drain on the ground until your permanent pipe thaws.

Jim Fry wrote:One time my brother had a frozen pipe on his farm. He stuck a wire in each end of the blockage, connected the wires to his welder, and turned it on. The arc through the ice melted the blockage. I make no claims that it was a good idea. What I have done is to wrap all vulnerable pipes with heat tape and insulation. Another thing you could try is to just put another drain pipe thru the wall and let it drain on the ground until your permanent pipe thaws.

Thank-you, Jim. As the pipe is underground, I have no idea of where the blockage begins or ends. If I could find a neighbour with a welder (what type of welder?), I have lots of wire. Would it matter what type of wire?

Ughhhh! All the time. Probably twice a winter. I just had to clear two days ago. Luckily it only worked out to probably three feet of ice. I have in the past had to clear 60 feet of it.

So, what I do now is I drop a bucket below the outlet point of the first mulch basin, drop a utility pump in the bucket. I have a 1/2" x 100' water line that I attach to the pump and feed up the outlet pipe until I find the ice. Pour hot water into the bucket and turn on the pump. The water flows up the line and back down into the bucket and it basically just feeds itself. You can burn through a fair bit of ice pretty quickly. Go inside and stay warm. Go back out and push the line up every few minutes. Easy peasy.

The only time I have the problem is when I don't put warm/hot water down the line on a daily basis. I like the gate idea....hmmmm?...I guess I'll break out the shovel this spring!

Good luck!

I was thinking about how to account for cold winters using grey water year round (no septic), and was thinking of running it through a greenhouse or under some other protected soil, like beneath compost piles. So from the house, through the greenhouse, under the compost pile, and then out into the mulch basins around the (planned) fruit trees. Getting enough slope to ensure drainage before it starts to freeze up is another bit to consider, I guess frost heave can play havoc with that.

Hi Mark,
All good as long as you are in a "warm-ish" cold climate. Where I live there is no keeping a compost pile warm or a greenhouse warm...or a compost pile in a greenhouse warm for that matter. We just came through a week of -35C (-31F) and nothing stays warm in those conditions.

But I like the idea for sure!

The main culprit in my system is the small dribs and drabs of water going down, (washing your hands etc) and this flows down and freezes in layers before it reaches the end of the pipe. It builds up and builds up until it blocks the pipe completely. Then you keep putting water into the system and it just becomes a longer and longer "grey-cicle". The cure is to make sure you move enough hot water through on a daily basis so it doesn't have a chance to build up. A fine line between conserving water and wasting time unfreezing the pipe.

I considered running a heat tape through the pipe so I can melt a blockage when it occurs, but the price was pretty high for the amount needed and the cable would probably collect all the nasty bits (hair etc.) and make for a blockage. Vicious circle.

Keith Ahlstrom wrote:Hi Mark,
All good as long as you are in a "warm-ish" cold climate. Where I live there is no keeping a compost pile warm or a greenhouse warm...or a compost pile in a greenhouse warm for that matter. We just came through a week of -35C (-31F) and nothing stays warm in those conditions.

But I like the idea for sure!

The main culprit in my system is the small dribs and drabs of water going down, (washing your hands etc) and this flows down and freezes in layers before it reaches the end of the pipe. It builds up and builds up until it blocks the pipe completely.

This is why I have a dam to close up the pipe at night time or whenever I know I won't be running water for any length of time. The night this froze the wind chill went to -37C. I should have closed the dam much earlier in the day.

It looks like I'm going to have to live with this until spring thaw, which means May or June until the ground is thawed. At least I figured out how to wash my hair, followed by a "sponge bath." Did laundry at my sister's yesterday. Thanks heavens I kept my small collectionn of antique enamelware bowls and pails with handles and lids. They're very handy and were probably used for the same purposes when they were first made.

I'm trying to think of this as a challenge. However, it means putting off a lot of things I had planned on getting accomplished during the winter.

Well...Jane...I say give the waterline trick I use a try. It works great for me. I cleared the three foot greycicle in about 45mins. You can also try a pressure washer (heated) You can rent them from just about any equipment rental place.

Good luck with your pipe.

Keith Ahlstrom wrote:Well...Jane...I say give the waterline trick I use a try. It works great for me. I cleared the three foot greycicle in about 45mins. You can also try a pressure washer (heated) You can rent them from just about any equipment rental place.

Good luck with your pipe.

Thanks, Keith. I don't have a pump or a long line like you have. Perhaps I could try a pressure washer, but how would I get hot water to it? I couldn't run it from the kitchen tap (closest to the problem) I don't think. Am I just short on imagination?

Jane!...don't suffer...where there is a will, there is a way!

So, The waterline I have is from Canadian Tire...I think I spent 20 bucks for 100'. (it comes in a big roll...think garden hose, but black and more rigid...like pex tubing, but not as expensive) I originally used garden hose, but scared the bejeezers out of myself when the two sections I was using pulled apart in the pipe. Thankfully, it happened just as the connection came out of the pipe. Having a garden hose stuck up in your grey water line would SUCK! If you have a short-ish run of pipe from the outlet to the house and only need one hose...go for it. Garden hose works, but it can sometimes be like pushing a rope up a hill...the water line is far more rigid and just doesn't buckle.

The pump was from Canadian Tire as well...whatever you can get cheaply. I love and use these kinds of pumps all the time. I can't even count how many times they have saved me from disaster. $60...$80 it's all money well spent! I can wager your nieghbour has one you could borrow.

The hot water comes from my canner. I boil up some water and fill the bucket. Fill it up again so I can top up the water in the bucket. (remember some of the water will be in the line and coming back down the pipe so you will need more than the single bucket for the pump to have something to pump back up.) Cold water works as well....just slower.

Good luck!

Keith Ahlstrom wrote:Jane!...don't suffer...where there is a will, there is a way!

So, The waterline I have is from Canadian Tire...I think I spent 20 bucks for 100'. (it comes in a big roll...think garden hose, but black and more rigid...like pex tubing, but not as expensive) I originally used garden hose, but scared the bejeezers out of myself when the two sections I was using pulled apart in the pipe. Thankfully, it happened where just as the connection came out of the pipe. Having a garden hose stuck up in your grey water line would SUCK! If you have a short-ish run of pipe from the outlet to the house and only need one hose...go for it. Garden hose works, but it can sometimes be like pushing a rope up a hill...the water line is far more rigid and just doesn't buckle.

The pump was from Canadian Tire as well...whatever you can get cheaply. I love and use these kinds of pumps all the time. I can't even count how many times they have saved me from disaster. $60...$80 it's all money well spent! I can wager your nieghbour has one you could borrow.

The hot water comes from my canner. I boil up some water and fill the bucket. Fill it up again so I can top up the water in the bucket. (remember some of the water will be in the line and coming back down the pipe so you will need more than the single bucket for the pump to have something to pump back up.) Cold water works as well....just slower.

Good luck!

Okay, I'll give it a try. What kind of pump is it (so when I ask if I can borrow one, I know what to ask for)? I can afford $20 for the waterline. My distance is approx. 25 feet.

sounds like your looking for some sort of submersible electric pump, they come in many different shapes and sizes, most often used for sump pumps, pond aeration/circulation, etc.

http://www.canadiantire.ca/en/pdp/mastercraft-submersible-utility-pump-0623575p.html#srp

Keith Ahlstrom wrote: You can also try a pressure washer (heated) You can rent them from just about any equipment rental place.

Good luck with your pipe.

Keith, this gives me an idea and I hope it is considered consistent with the current thread.  I have a frozen hydrant just now due to not adjusting the plunger depth properly before winter freeze-up (see photo below).  I was thinking of using tubing that shuttles windshield wiper fluid from the reservoir to the wiper nozzles to transfer a hot, somewhat concentrated Calcium Chloride ("Ice Melt") solution up through the hydrant spiggot and see if by over-filling and re-heating the effluxed fluid would "drill" down through the ice that had collected in the hydrant pipe.  I don't know how high up the water column was when it froze, so it may be a long project, but the total length of pipe is 3 feet above ground and about 5 feet or a bit more below ground to where the plunger/weep hole are situated.  But I hadn't considered a heatable pressure-washer unit.....which is built for several types of aqueous solvents and detergents, yes?  The idea would be that, if the thaw is successful, the force of the well-pump would purge the solution out into a large drum which could be used to collect the calcium chloride solution for disposal later. (...)  Possible?

I like Keith's idea.  Without a pump you could also run a garden hose.  Even tap water might melt ice if it wasn't too cold.  Test it first.  You can connect to a hot-water tap but you might need an adapter.  The drain on your hot water tank might fit a garden hose.  You could also just raise one end of the hose higher than the other and use a funnel to pour hot water in.

I think salt might be more effective than antifreeze.....    I haven't tried this, but here's an idea.  Make a block of salt that will fit inside the pipe.  I suppose you could do this by dampening the salt, packing it into a mold, and then heating it to dry it.  Or get a cardboard tube or a sock and pour salt into it.  Wet it with hot water so that the sock is doused in brine.  Take a long pole (or cut a straight sapling).  With a string, tie the sock closed and tie the sock to the pole.  Gently push the salt block through the pipe.  Use bungee cords to pull the pole forward.  Put markings on the pole to measure its progress.   I haven't tried this yet, it's just an idea.  

(Feeling foolish for not thinking of any of this sooner, I just spent 4 days messing with this and finally ended up bypassing the pipe!  haha.  Life pro tip: Don't install plumbing in exterior walls, lol.)  

Worth a shot! It should work, but I don't have an intimate knowledge of those hydrants.
I wonder if you built up the ground level around the hydrant if this would raise the frost line? I mean a pretty large circle...radiating 5 or 6' out from the...ahhh nevermind!   Winter is truly a pain in the butt!
I keep wondering if it just doesn't make more sense to pack up and swing in a hammock on a beach for 6 months a year. I am pretty sure the expense of heating, fixing and defrosting would pretty much cover the vacation.

It seems that I remember seeing a thread about using manure to keep pipes from freezing and I found it:

https://permies.com/t/62188/frozen-asset

Regan Dixon wrote: It's good to remember that burying something deeper, doesn't automatically equate to digging a deeper trench.  Piling materials on top can accomplish the same thing.  (Why had I forgotten that?)  ... so I can place soiled bedding effectively.

This is what he was replying to:

Travis Johnson wrote:Regan, I know your intent was not to start a discussion on trying to prevent the water line from freezing, but I believe you have the solution to your problems right on premise.

We have a waterline going out to our house and there is a certain spot that despite insulation and burial, it is not low enough to prevent freezing. This is frustrating, so we take a bucket load of sheep manure and place over that spot in the line. It has never froze since doing this, the manure and hay bedding causing the area to warm up and stay running.

We do not have a lot of manure over the spot, may 2-3 wheelbarrow fulls, but it gets VERY cold here, we are talking -10 to -20 below (f) and it has yet to freeze. I am not sure if you have a tractor or not, nor do I know the length of your pipe, but maybe you could layer the pipe with your animal manure and prevent the line from freezing? (I might stay back from the stream edge so you manure does not foul it, which may mean burying your line a bit deeper there, but a wee bit of digging is better than a lot.

Just a suggestion! If you think it is silly, carry on my friend! I admire your ability to live without!

Jane, If you don't have access to manure, maybe you could dump your composting toilet over the line?  

Another solution that I thought of is the cover the line with bales of hay, maybe that would work to thaw it out.

Keith Ahlstrom wrote:Worth a shot! It should work, but I don't have an intimate knowledge of those hydrants.
I wonder if you built up the ground level around the hydrant if this would raise the frost line? I mean a pretty large circle...radiating 5 or 6' out from the...ahhh nevermind!   Winter is truly a pain in the butt!
I keep wondering if it just doesn't make more sense to pack up and swing in a hammock on a beach for 6 months a year. I am pretty sure the expense of heating, fixing and defrosting would pretty much cover the vacation.

Yeah, I agree that winter can be a pain in the butt sometimes....when things are going well at -20 F, I can be smug that I have all of the contingencies accounted for.  A frozen hydrant brings me squarely back to reality....very humbling!  All the more so because I know that each fall I *need* to make sure the hydrants are draining properly after shut-off or they will freeze up....as sure as the sun rises in the east.  Unfortunately, the hydrant comes up through a cement floor on the inside perimeter of a large (uninsulated) outbuilding, so there would be no way to grade more soil up in an attempt to raise the frost line.

Now the "hammock" fix sounds truly intriguing! .....  and I've heard that combining that approach with Mai-Tai's and Pina Coladas as solvents, your frozen hydrant woes vanish quite quickly!....

Jane,
So? Did it work? Or did you find a better way? I am always open to better ways!
(maybe it just cleared itself...that is the best option.)

I'm sorry to admit that I didn't do it, Keith. No one I know has a pump and it all just seems like too much for me. I'd have to stand in the pond, which would melt; there's no way I can get very much hot water down there; and I just give up for now. After days of -40sC with wind chill, it's a balmy -9 right now, and going above zero for a day or two this week! I know that the ground won't thaw, but at least it's not quite so frigid. I've become quite adept of coping with things as they are.

I thank you so much for your help. I didn't want to admit that I hadn't followed your advice. Perhaps there will be a miracle at some point.

i'd put some de-icing salt down it and let it do its thing

I did, but it didn't do anything. I also tried RV antifreeze.

Jane,
No shame at all. The list of things around the homestead I have yet to tackle is long and exhausting.
If I were even remotely close to you I'd come do it for you. Easy peasy! But I am a few thousand Km's away.

I know all about "manual drain systems" I went 3 years with no running water with everything collecting in 5 gallon pails. It worked just fine...just a bit tedious.

Spring is coming....spring is coming.

Yes, according to my neighbour whose kitchen drain just opened this morning: "72 days to spring and 63 until daylight savings."

Sorry that happened to you Jane.  

You could try running hot water into it if you had enough garden hoses to run the hot water heater drain out to the bottom of the pipe and back up it.

Or maybe there's a way to install a bypass.

One idea to help keep it clear next year might be to install an inexpensive "bell siphon".  This would prevent water from slowly trickling out that would tend to form an ice dam, and instead would automatically wait until several gallons had accumulated and then flush it out all at once.  Video showing how this mechanism works.  

Mike,
Bell siphon! Thanks!...not sure how I would work that into my system as I would need to either place this under all the sinks or in a heated box outside the house...hmmmm?...that tropical winter retreat still sounds better.

Thanks for the idea.

A solution for next year might be to have a greywater barrel, with a sump pump that auto-empties once a day or with a floater switch that turns on once it fills.

You could set it up where in spring/summer/fall it operate like it currently does and in winter it diverts into the greywater barrel+sump pump setup. Due to the fact it seems like it is going to be a yearly problem with whatever the climate is doing  

Keith, (edit: and all the good folks, )

Glad you liked the idea.   Would it not work to use one just before it goes outside?  By the way, toilets and plumbing traps work the same way, and it can be enclosed.  Yeah, insulated or heated.  

I was also wondering about using steam to preheat the pipe.  If a thermal mass was heated up with a pilot light or an electric heating element, then when siphon water dumped on it, it would flash to steam.  The steam would then condense preferentially on the cold parts of the pipe.  The steam would carry more heat per unit water than even boiling water, it ought to reduce icing.  It seems like it would be a more efficient use of heat.  Cycling hot air through the pipe might be a relatively energy efficient way to help dry it out.

Another idea is to run brine through the pipe, collect it at the outflow in a catch-basin and recirculate it with a pump, (at least if it didn't corrode any metal).  When the top of the basin froze, that relatively salt-free ice (graycicle) could be skimmed off and discarded, leaving relatively concentrated brine underneath.

Another idea is to run an electric wire through the pipe and use it as a heating element.  Funny anecdote, I even heard a report of someone in Europe running 230 Volts through a very long piece of telephone wire in a cold water pipe!  While I can't exactly recommend doing that, I have to admit it does technically work.  Ice cold water is such a good heat sink that it technically even allows telephone wire of all things to be used as a crude heating element.  I was going to say it isn't particularly safe, although if it's insulated, grounded, the ground is frozen, the wire is immersed, it's away from bare skin, and people know not to touch it when it's on, maybe it isn't all that unsafe either.  

Another idea is to try to insulate the pipe, from either the outside or inside.  Even a thin waterproof insulator on the bottom of the pipe should help, since this is where the water contacts, and where the main thermal path is.  

Another idea is to try to coat the inside of the pipe in grease or wax so ice doesn't cling to it.  If slush forms in the liquid but is flushed out, in a way this is good since heat is released during freezing, essentially "warming" the water around it.  Slush should still flow, the problem is with build-up on the pipe walls or larger crystals causing clogs.  This is also where a brine solution helps because it's more likely to form slush.  

Maybe there's a way to knock the iced bits loose with thermal cycling, vibration, pipe flexing, steam, compressed air, or a piston.

If there was a predictable schedule time for when hot water went down the drain, then that could be used to preheat the line and the graywater tank could be emptied following that.  

MIke! Oh man alive we should be neighbours! Those are a bunch of interesting ideas. I will repeat the words of A certain robed Indian gentleman: "I am but a simple man". I'm in no - way, shape or form smart enough for most of those things.

The siphon would need to be dug down outside the house insulated etc etc. (The house is a slab on grade with the pipe leaving the foundation wall, about 6" below grade.) But I may do it just to see what's possible.

Wow, so many creative minds!

I think that next year I'll remember to close the dam on the pipe when I won't be using water for a while in very cold weather. Just closing it when I went to bed worked fine for temps down to -20C, but this year the cold has broken all records.

Today's temp is going up to +2! It's also snowing...again.

Abe Coley wrote:i'd put some de-icing salt down it and let it do its thing

Just updating since I think this did in fact work with a little help from Mother Nature.  This refers to the frozen water hydrant post farther above.....the water was indeed frozen within the pipe nearly to the position of the spiggot.  I had force fed the spiggot with some pressurized solution of Calcium chloride and noted that most of it spilled right back out, suggesting that there was little extra headspace above the frozen column of water.  So  I left it.....for a few weeks!  Then, with the temps warming for a few days above freezing (but nights still freezing well), I kept trying the hydrant....but to no avail.  Thinking it was stuck for the season and with the temps dropping again, I gave up.  But, as usual, couldn't resist some days later pulling up on the hydrant spiggot.....and it was free!  Water came out like it had never been frozen, which was quite unusual.  So I let it run for a bit, tasted it and could still perceive some salt, so after a few buckets of flushing, called it good.  It's been moderate in temperature now for a few days and it's trying to decide if it wants to freeze up again, so I'll put another dose of ice-melt down it to try to convince it otherwise, then with having Friday off work, will try to re-adjust the plunging rod like I should have done before.  Here's hoping!......

I know you are looking for simple and most likely inexpensive solutions to the grey water pipe freezing.  Living in Alaska I know your trouble with frozen drain lines and on occasion frozen water lines.  Last time I had a septic line freeze up I had to call the local sewer pumping company.  They brought out a steam thaw system.  Took about 15 minutes to thaw it out and get it running freely again.  Cost was not exorbitant, but for the life of me I cant remember exact cost.  If the pipe had been copper or other metal a welder with long leads works well at thawing frozen lines.  One lead connected at one end of the pipe/frozen area and the other lead connected at the opposite end.  Last time I had to do that I wound up having to call someone because my welder leads and my 220volt supply were not long enough.  Took exactly 5 minutes to thaw out my copper water line.

It's amazing, but I'm happy to report that the ice thawed! We've had above-zero temps for quite a few days lately, three in a row last week. i really don't know if the antifreeze worked or the salt worked or if it was simply the warmer weather. It re-froze after one day, but thawed again a few days later, and now it's been free for a few days. I think it's safe to say it will remain free now. I'm keeping the dam closed when I'm not using water (most of the day) as it's well below freezing again, but not nearly as cold as it was, and the forecast calls for above-zero again soon...very strange winter.

I'm very financially challenged, but I really hope I can find a way to get a holding tank in the spring. Because of the configuration of my property, excavation will be very expensive. Then there's the tank itself, a plumber, etc., etc. Warning to all who are contemplating composting toilets instead of a septic system: it's not a whole lot of fun looking after them when you get older and it's frigid outside!

Thank-you all for your help!

Walt, that works, although if there's an open circuit I think the welder will generate a high voltage arc which may or may not be a problem.  (For example, you don't want it to catch something on fire.  If possible, it might be good to first use an ohm-meter to test for continuity.  Also try to vent both ends of the pipe first and make sure there's no trapped sewer gas to ignite from a spark.  Keep a fire extinguisher on hand.).  One way to try to prevent arcing might be to put some sort of shunt-resistance in parallel with it, like a "power resistor", to reduce the chance of an open circuit.   This could be almost anything from a stove heating element to a toaster oven, or the graphite in a pencil lead, although use carefully since these present a fire-risk as well.  Another way might be to use a large 12 volt lead-acid battery, which avoids the high voltage problem, although it still has similar risks.  Certainly don't touch the pipe when the welder is on.  Use a grounded outlet preferably with a ground-fault GFCI circuit breaker.  To reduce the risk of shock, don't use in water.  Keep you and the welder dry.  

Maybe a bit off topic, but another update to the frozen hydrant issue described in posts above within this thread and a question to those who may have experienced the same problem.  Yesterday I was finally able to get the hydrant head unscrewed from the pipe and pulled the plunger rod up (see the photo in the 1/2/2018 10:35:53 PM post above).  With the pipe free of the spiggot and innards, the main water was turned back on to flush the pipe and to test the weep-hole (drain-hole) clearance at the bottom of the pipe.  When the main water pressure was turned off, water remained in the pipe....in other words, it was not draining as it should---the weep hole must be plugged.  So we are planning on digging it up next spring, but I was wondering if anyone had ever had this problem and simply applied some sort of pressurized air/water to the pipe to try to 'blow out' any obstruction that may be blocking the weep hole.  If you think about it, with the handle down on the spiggot ('off' position), one might attach some sort of pressurized air to the spiggot mouth which in principle should force the trapped water out of the weep-hole as that would be the only point of pressure relief.  If the obstruction is something like corrosion or other factor that cannot be dislodged, then this clearly would not work, but just wondering if anyone had tried this or similar.   Thoughts? ...... Thanks!

I have, and sadly your problem sounds similar to mine, but I ended up digging it up because my hydrant ended up being damaged at the valve. There was no salvaging mine; I had to buy a new one. :-)

My go-to ground thawing method is to use sheep manure and hay (the bedding the sheep are on). The resulting compost puts out a lot of heat. I pack it around my hydrants and water lines to keep them from freezing.

Last year my radiant floor heating system froze up, so I packed manure/bedding around the edge of the house and in a few hours it thawed it out.

I guess it's time to update my issue. In May I used my inheritance from my step-mother (who died at age 98) to get a 'normal' toilet and had two big holding tanks installed. It ended up costing over $12,000! It turned out that the contractor I hired who said that he'd installed many tanks before, was a liar. He had good reviews for other things, so I stupidly trusted him. There are very few people around here who do this sort of thing. This was obviously his first time. My property goes downhill from the house. Tank #1 is fine, but tank #2 behind #1 is only slightly buried, so I'm worried about freezing again. The plumbing and everything else is fine. One thing I really wish someone had suggested (or my brain was working better) is that I keep the grey water and use the tanks only for the toilet. It's amazing how much water is used, even though I'm really, really careful and even dump my dish water straight outside. Pump-outs cost $260 and I've already had one!

Travis Johnson wrote:.....my hydrant ended up being damaged at the valve. There was no salvaging mine; I had to buy a new one. :-)

That's where I suspect we are headed.  Knowing now that we have 3 ft above ground with the exposed part of the pipe and 7 ft below ground, I'm thinking we will need an excavator as my own backhoe has a maximum reach of 7 ft under ideal conditions.  Since we know that the bottom of the pipe should have plenty of rock around it in all directions for drainage, it's clear that we may need to dig below the end of the pipe if it was poorly gravelled in the first place.  We need a new concrete pad there anyway when the time comes, so bring on the jack-hammers to remove the old one!

Jane Weeks, it must be code differences but weren't you allowed the option of a tank + drainfield combination?  I've seen locally that more people are being "recommended" by the county to put in pump + mound + drainfield systems in order to protect water quality better.....somehow....in someway that I've not been properly informed. (??)  Our local pump rate is $175 USD per tank and the drainfield allows for some extra time before that needs to be done.  As Travis noted, anything to get that second tank under some kind of insulation.  Around here (south and west of you on the other side of Minnesota) in low snow years, many seem to pile up straw bales on the tank which seems to help.  With regard to grey water, we keep the kitchen sink still going to the septic tanks, but remember that any other sink/drain can, at a future time, be "judiciously redirected" as grey water with a little help from a Sawzall and some assisting friends with the know-how.