Small Cabin

Small Cabin Forum
 - Forums - Register/Sign Up - Reply - Search - Statistics -

Small Cabin Forum / Off-Grid Living / Black Tank
Author Message
travellerw
Member
# Posted: 5 Feb 2024 12:08
Reply 


Ok, after 3 seasons of a temporary sewer solution (portable RV tank hooked to the toilet), the wife is asking for more.

First thing to know is that zoning does allow surface discharge due to size of our property and location of the cabin to the nearest property line (over 500 yards). However, we mostly use the current portable tank to haul the sewage to the local RV dump about 15 min away.

The big problem is we use the cabin in the winter (6-8 weekends over winter). So, she wants a solution where we can do #1 and #2 in the toilet on those weekends. Not an option with the current solution.

Of course I have looked into a proper concrete or fiberglass underground holding tank. Unfortunately, our frost line is crazy deep here and the experts are recommending 13-15ft hole for the tank. Its usually 8-10ft but due to our infrequent use they are worried there won't be enough biological heat and risk freezing in a cold snap (it gets past -40C a couple times a winter). As you can imagine this solution is pretty damn expensive and I'm struggling with the costs for 6-8 weekends.

As an alternative, I'm thinking of instead doing a larger above ground tank under the cabin (directly under the toilet). At the start of winter I would completely empty the tank and then pour a mixture of RV antifreeze and salt to start things off. Each time we use the facilities, we flush with RV antifreeze instead of water. The tank would easily be large enough for the whole winter (looking at 100 imp gallon). At the end of winter, I would top the tank with water to dilute everything, then dump (either haul to RV dump or just surface discharge using a mascerator pump I already own). As you can imaging this solution is WAY cheaper at about 1/8-1/10th the cost of a buried tank.

I know there are quite a few owners here in ultra cold climates and I'm hoping someone has done something similar (maybe in an RV). Thoughts?

P.S. Yes I have looked into an incinerating toilet, but I don't have the power to run it. Its also too cold for a composting toilet to work.

gcrank1
Member
# Posted: 5 Feb 2024 12:31
Reply 


Imo and e a composting T can work for winter.
You need to use a urine diversion to a container you can dump at least daily.
For solids you use a lined (we use hay) bottom and sides 'bucket', the solids are covered with a scoop of sawdust/chips after each use.
Each day (for us, each morning and if needed before we leave) the bucket gets the short trip to the outside compost bin that is, of course, dormant. It gets another covering if needed but usually doesn't because each bucket has so much organic material in it.
Come spring the bin activates at its own pace and all is good.
This is not unlike what my grandparents grew up with except their 'night pail' got taken to the outhouse each day. Imo the compost bin is far better.

kittysmitty
Member
# Posted: 5 Feb 2024 15:21
Reply 


I use a Sun Mar NE (non electric) at the camp. It does freeze in winter but just acts as a holding tank until the weather warms up in spring.6-8 winter weekends should not be an issue.

travellerw
Member
# Posted: 5 Feb 2024 16:46
Reply 


I should have also posted that I had such bad experiences with composting toilets in the past that they are really not an option.

I have no interest in keeping the dry material, dealing with urine diverters, ect. Especially with 3 teenagers that are at the cabin almost every weekend in the summer. I can barely get them to flush, there is no way they will deal with a urine container at the end of the weekend (and I can imagine what that would smell like when we came back the next weekend after it sat at +30).

paulz
Member
# Posted: 5 Feb 2024 17:51 - Edited by: paulz
Reply 


I have an above ground 500 gallon tank, 250’ downhill from the cabin. Conventional flush toilet. I’ve had a sewer truck pump it, or I pump into 50 gallon barrels and haul it home to my grid house.

What I need to do is add a leach line so I don’t have to haul the loose stuff.

spencerin
Member
# Posted: 5 Feb 2024 21:08
Reply 


Where exactly would you surface discharge its contents? To confirm, your county Health Department (or equivalent) would actually let you do that?

travellerw
Member
# Posted: 5 Feb 2024 22:05
Reply 


Quoting: spencerin
Where exactly would you surface discharge its contents? To confirm, your county Health Department (or equivalent) would actually let you do that?


Absolutely allowed where I am. I'm surrounded by cattle farms and cows tend to do their business outside. Our family of 5 would be a drop in the bucket compared to the 10,000 head of cattle within 1 mile of us. Here are our rules:

Open discharge sewage systems may be installed provided the point of discharge is
not less than:
50m (165 ft.) to a water source or water well
100m (330 ft.) of a licensed municipal water well
45m (150 ft.) to a water course, except as required by Article 2.1.2.4 of the SOP
90m (300 ft.) to a property line
45m (150 ft.) to a building

We have 164 acres, so I have no shortage of places to discharge. In the past I have towed the portable tank deep in the forest and dumped it there. For a cabin tank, I have a 250M 1" line that I would run into the forest. We have no water courses on our land and meet all the other regulations.

travellerw
Member
# Posted: 5 Feb 2024 22:07
Reply 


Just to clarify, this is for rural land that is classified as farm land. Open discharge would not be allowed in a typical "cabin acreage".

bushbunkie
Member
# Posted: 6 Feb 2024 09:23
Reply 


We’re in Ontario Canada and we can get pretty cold winters. We head to the cabin 6-8 times during December- March. We have indoor plumbing and water but both are shut off for the winter. For washroom facilities, we have found simple works for us. My wife and her girlfriends have used this system for years in winter, though some women may be “too fragile” lol…to consider it.
We built this toilet box originally in our outhouse, and still keep it in use all year as overflow when company comes to not overload our septic. I simply put the box in the washroom in the winter beside ceramic toilet. It’s built off the “ humanure” concept. Once we go number #2, we simply cover with a couple scoops of peat moss. Peat moss is the key since it absorbs both fluids and smell. If I have a really bad #2😂, I simply crack window and spray a squirt of deodorizer….but honestly, smell is gone very quickly because of the absorption by the peat moss. When it’s full, I simply dump in our designated area where it gets composted for flower garden. Bucket is rinsed clean and back into the toilet box.If you want, you can even dump after each #2, so there is always a fresh bucket. This won’t work for everyone, but it is simple and works…and it’s inside where it’s warm. This system is also used in some southern states as back up where power outages are common.
IMG_0097.png
IMG_0097.png


paulz
Member
# Posted: 6 Feb 2024 09:43
Reply 


Looks inviting! 😀

bushbunkie
Member
# Posted: 6 Feb 2024 10:58
Reply 


Better than a cold seat in a winter outhouse!😂

Brettny
Member
# Posted: 6 Feb 2024 11:03 - Edited by: Brettny
Reply 


Quoting: travellerw
I should have also posted that I had such bad experiences with composting toilets in the past that they are really not an option

I too had issued with a composting toilet until I put a urine diverter. Issues meaning coming back to maggots coming out of the toilet seat and the smell even after 1 day was terrible. My Urine diverter is a one piece that sits over 1.5in PVC with a P trap down to a 5gal bucket in the ground. Theres next to no smell now, I dont deal with the urine and the waste bucket need to get dumped less. In winter I put a bit of antifreeze down the P trap after each use. I should note that this is in a small external outhouse not in the cabin.

They also make LP fired incinerating toilets that use a bit of 12v power.

travellerw
Member
# Posted: 6 Feb 2024 13:09
Reply 


Quoting: Brettny
They also make LP fired incinerating toilets that use a bit of 12v power.


I have spent a bunch of time researching them. Talked with a few owners and I think they are a great solution. However, they are about the same cost as me putting in a small buried tank and outlet field. Cheapest one here in Canada is about $6K with taxes and shipping.

After a couple of calls yesterday, I'm starting to research plastic tanks instead of concrete for burial. They are quite a bit cheaper. So I may just bite the bullet and go that route. Still looking at options!

spencerin
Member
# Posted: 6 Feb 2024 20:14 - Edited by: spencerin
Reply 


I second the plastic tank, and buried if possible. More for the resale value of the place. Imagine trying to sell it to someone, and their reaction when they find out human waste is being discharged on the surface of the property, even if somewhere else.....

Plus, what if your friends in the local gov decide to reclassify your land as cabin acreage? Maybe the surface discharge method would be grandfathered in, maybe not, but if so, maybe it still further complicates a sale.....

travellerw
Member
# Posted: 7 Feb 2024 11:13
Reply 


Unfortunately a buried tank is only 1/2 a solution (it just solves the freezing problem). It still need to get rid of the effluent. So either trucking or surface discharge.

I'm kinda shocked at your take on surface discharge. It must be very different in your area, but around here its really common for rural land. Hell, in some small towns there are still houses with an outhouse in the back yard. It would be %100 expected on a property like mine and there is no risk of rezoning in the next 3 lifetimes.

So, I think the plan will be a 500 gallon plastic tank buried to a 10ft depth. I will truck or discharge for now, but this gives me the option of doing a mound or other solution down the road. Unfortunately, due to the infrequent use, we still may need to use antifreeze in the winter.

FishHog
Member
# Posted: 7 Feb 2024 11:37
Reply 


Old composting toilets had issues but urine diversion is the key.
I would never deal with a black tank as opposed to my composting toilet
But I also have zero issues with an outhouse nor does my wife luckily. A nice clean outhouse with a styrofoam seat and portable heater for winter meets our needs just fine

Brettny
Member
# Posted: 7 Feb 2024 16:30
Reply 


Quoting: travellerw
Unfortunately a buried tank is only 1/2 a solution (it just solves the freezing problem). It still need to get rid of the effluent. So either trucking or surface discharge

That's what a leachfield does. Takes liquids and disperses them.

If this is a weekend place I wouldnt expect the tank not to freeze if not below frost line. Salt only works to about 11*f. Your really going to have to dump alot of antifreeze down there.

travellerw
Member
# Posted: 7 Feb 2024 18:56
Reply 


Quoting: Brettny

That's what a leachfield does. Takes liquids and disperses them.

If this is a weekend place I wouldnt expect the tank not to freeze if not below frost line. Salt only works to about 11*f. Your really going to have to dump alot of antifreeze down there.


Yup, leachfield or Minnesota mound. I may do something like that in the future. Right now, I don't want to dump 4-6K to build a mound (in just materials).

The tank I'm looking at can be buried 11ft, but equipment I have access too is limited to 10ft. That will put the bottom 2ft of the tank below the frost line. Hopefully that will be enough, but time will tell! If I want to put the whole tank below the frost line, I will need a concrete tank and a 20ft hole. That would put the cost SUPER high (damn concrete tanks are spendy).

Brettny
Member
# Posted: 8 Feb 2024 07:56
Reply 


Use foam board above the thank.

travellerw
Member
# Posted: 8 Feb 2024 11:08
Reply 


Quoting: Brettny
Use foam board above the thank.


Where abouts? Do you mean right above the tank (like backfill to the top of the tank then cover in a few inches of foamboard, then backfill to top)? or do you mean backfill most of the hole and put foamboard near the top?

At the very least I have to backfill to the top of the tank as plastic tanks aren't flat/square. They have all kinds of contours to deal with the depth.

Brettny
Member
# Posted: 8 Feb 2024 11:56
Reply 


I would put it right at the top of the tank to riser.

gcrank1
Member
# Posted: 8 Feb 2024 12:43
Reply 


Think Ive seen that it should extend outward from the tank via. too

ICC
Member
# Posted: 8 Feb 2024 17:23
Reply 


We have a 325 gallon spherical tank buried at the cabin. This is for fresh water storage, but the principles are the same for waste water. It's about 54" in diameter and has a manhole extension of 24" height. The tank hole was dug deep enough to place the top of the manhole extension about 12" above the ground surface level.

I wish I had a photo or two but I don't have any easily accessible. I will try a word picture.

We used 4 inches of XPS foam to insulate a box shape around the tank. This was done with 1 and 2 inch thick pieces in layers. We used a lot of scrap cut offs that had been saved, but did use some new material too. The vertical foam extends down to about the largest diameter point... roughly half the share height. The vertical foam rises to about 10 inches below grade. Then we laid xps foam sheets horizontally out from the vertical foam for 2 feet.

So we have an open ended box shape of foam around the tank, with a flat collar of foam laid horizontally up to the manhole neck.

I then built a wood framed box around the manhole and insulated that with foam sheets. The insulated sides of the "well-head" box fit flush against the horizontal foam collar. There is a lift off insulated lid that fits tightly over that wood framed & insulated box. (I hope you are following this...)

The space between the tank and the insulation is filled in with a mix of 1 to 2" river rock and dirt.

We don't get temperatures as cold as Canada. However, it is below freezing for months and the frost depth can be as deep as 36". The water in that tank has never frozen. The coldest I have ever seen the water is about 45 F. In summer it is usually 55 F or so.

As an aside, we also have a 7 foot deep 4' x 4' pit with a heavily insulated lid inside the barn. Canned food and water jugs stored in the bottom of that pit never freezes either.


Oh one more thing.... most rectangular ribbed tanks I have looked at have a minimum volume of water requirement. IIRC, usually about 25% the total volume. That is to keep it buried as it could (try to) float if the groundwater level was high enough. A spherical tank may be emptied completely. That is why I selected a spherical tank.

Brettny
Member
# Posted: 9 Feb 2024 07:38
Reply 


Icc how are you plumbed into that tank for water? Sump pump in the tank with a curb stop style valve below frost or something?

ICC
Member
# Posted: 9 Feb 2024 10:29
Reply 


Quoting: Brettny
how are you plumbed into that tank for water?


I use a Rule inline submersible bilge pump. It works much like a sump pump. Rule sells them in 12 and 24 VDC which was one main attraction. Those pumps do not have foot valves, so when it is turned off water in piping that is higher than the water level the pump is submersed in flows back.

The submersible pump transfers water to an RV style water tank under the kitchen counter. 10 gallons. From that tank an RV water pressure pump is used to supply the sink and shower inside the cabin.

I have a water level indicator using a circuit I built in the 325 gallon cistern. It operates with a push button and indicates 100% full, 75% full, 59% full and 25%.

The fresh water tank inside the cabin has another circuit that senses low level (about 1 gallon left) and high level. When the level opens the low sensor the submersible pump in the cistern is turned on using a relay. When the high sensor reads full the submersible pump turns off.

The indoor fresh water tank has a drain valve piped to return water to the cistern. Same thing with the 6 gallon RV water heater that is also under the kitchen counter. The water from the heater can be drained back into the cistern too. No wasted water when the system is drained for cold weather.

-izzy

ICC
Member
# Posted: 9 Feb 2024 10:32
Reply 


The cistern is about 5 feet from the cabin wall and adjacent to the indoor water tank area. It is a 9 to 10 foot lift if the cistern level is low and that cuts down the rate of transfer a bit, but the Rule pump can keep up to the Shurflo in the cabin most of the time.

-izzy

travellerw
Member
# Posted: 12 Feb 2024 18:16
Reply 


Sorry for the late reply, just too much going on. Thanks all for the responses. IZZY that was really helpful.

I have also spoke with some people in the area and the agreement seems to be that as long as I go below 8ft I shouldn't have a problem. They were more worried about the black pipe freezing and recommended I go straight down for about 3ft before sloping towards the tank (PIA since this will be under the cabin). They also said to make sure I was using enough water to ensure everything gets to the tank. I will have problems if things don't go all the way down and sit in the pipe.

So, looks like I will be buying a tank and digging a big hole sometime after spring. Sigh, its really a never ending project (spent the whole weekend doing carpet in the loft).

Your reply
Bold Style  Italic Style  Underlined Style  Thumbnail Image Link  Large Image Link  URL Link           :) ;) :-( :confused: More smilies...

» Username  » Password 
Only registered users can post here. Please enter your login/password details before posting a message, or register here first.