24x24 in Western New Mexico

[hpinson]

Completed the pit, in nice compacted volcanic sand (Scoria?).  Pit is 3' 8" x 3' 8" x 6' deep. I hope that will do for a few years.



Added cribbing per the perscribed design. This is 6" ceder fencing, coated with Thompson Waterseal. Corner posts are 2"x4"x6' pressure treated.  Good thing my wife is an archeologist and likes working in holes!    She did a great job squaring everything up with a trowel and dustpan.
Getting in and out of a 6' hole is a bit of a challenge!



Completed cribbing. This should help discourage the walls from collapsing.



At this point I'm confident enough to send in the Liquid Waste Application (and $150) to The New Mexico Environment Department.  They will probably want to inspect, and chances are good that we will pass the requirements and get on to building the privy itself. I think the hardest work is over.

[MountainDon]

Nice precise hole. Only thing missing is the string grid.   

[MountainDon]

Do you have an actual plan for the structure that you could share?

[hpinson]

Sure.  What I'll end up with is really going to be a hybrid of lots of ideas. I've seen quite a few plans and can't say there is any one that screams out "perfect"!  I'll put what I found here, and start a new thread in the referral links section.

While not a plan, this is closest to what I'm going to build:

http://home.earthlink.net/~roygbvgw/outhouse1.html
http://home.earthlink.net/~roygbvgw/martino1.html

There is a pretty good chapter on building an outhouse in J. Wayne Fears book: How to Build Your Dream Cabin in the Woods.  It lacks measurements though.

Some of the better plans I found online are:
 
New Mexico Type Pit Toilet (perscribed by NMED):
http://ruratec.com/media/outhouse/new-mexico-type-pit-toilet.pdf

Casa de Dios ventilated improved pit latrine:
http://www.teamcasa.org/pdf_files/latrine.pdf

From Cottage Life Magazine:
http://cdn.cottagelife.com.s3.amazonaws.com/files/2011/05/Privy-Plan.pdf

And some sound design ideas: http://www.acacamps.org/campmag/issues/0807/stryker

I'll be substituting a USFS style fiberglass riser throne for the wood bench:
Fiberfab: 1030 West Foothill Boulevard, Azusa, CA 91702 (626) 633-0288 ‎
Far North Fiberglass: http://www.farnorthfiberglass.com/cones.html

The stainless risers are super expensive.

[NM_Shooter]

That is an amazingly nice hole.  Almost too nice to cover up and fill up.  I'm curious... what was the soil temperature at the bottom of that hole if the top stays covered?

I wish my soil at my cabin was more like that.  I wish the soil at my house was less like that.  Some people are just never happy.   

[hpinson]

Really we are lucky to have this spot.  Lots of room for a septic system should we want that in the future.  Most of the ridge is rocky scoria from the Jemez volcano with only a few inches of topsoil.  This area is some sort of bench, where the soil / sediment has collected over time to quite a depth.

It was nice and cool in the hole on a rather hot day in early April.  A few yards over, the ex owner had dug a root cellar (now collapsed).  So it was cold enough in summer / warm enough in winter for food storage.  I did not think to take the actual temperature though.

[rick91351]

Sort of hate to show too much excitement over a septic pit but you guys rock man!  So 

You can have your pit pumped once in a while sort of like the State and Fed Camp Grounds.  The way that soil looks it will stand the test of time and then some.  Did the wife find any treasures?   



 

[hpinson]

Nothing...  completely barren, which is surprising because Gallina Indian artifacts are everywhere around here (we are near Chaco). It's mostly pot shards and obsideon cores that you find.  But most of that is at of near the surface.  I found a bayonette once when digging a two foot hole for a rose bush, at my home in Central NM. It dated to around 1910, Army.

I think you are talking about a vault privy, which is really a sealed tank, that holds the septage, and can be pumped, like the USFS uses.  It's a whole different set of rules for those, and I think they are really best for high volume, cold weather, or no-soil situations where decomposition is not going to occur. Plus I think they are much more stinky. This is going to be such low volume; I hope the waste will for the most part compost at a rate similar to input. We'll find out though...  This is why the state makes you designate two alternate pit locations, so you can move to a new pit if the first one fills. Hopeing 6' will keep us going for at least 10 years though.

Now I'm starting to get an idea what it was like to hand-dig a well.

[hpinson]

Permission granted.    I now have one year to build an outhouse.

I think I'm the first person who asked the County permission to build an outhouse in the last 25 years.

[BADB0Y]

Good news! Congrats. I intend to build a composting outhouse myself. I grew up around them, but my wife (pure city girl) is mortified be the thought of it. LoL

[John Raabe]

I lived in Hawaii with a hand dug pit outhouse that had been in the same spot for probably 20 years. Low volume use, like you say. It composted down but the 6' hole was about 4'-5' full at that time. It was about time to dig another hole and move the little building.

[MountainDon]

Permission granted.    I now have one year to build an outhouse.

Way cool! A legal privy!!   

[hpinson]

And the stamped Liquid Waste Permit just arrived in the mail today. I have to say that the NMED field office staff member I worked with was very fast and helpful.  The whole application process took about a week and a half.

[MountainDon]

Almost painless   

[Don_P]

Our little shack out back looks the same, I sited it with the county health dept ~25 years ago. It saw light and then no use once we got the swirly inside. We kept a trashcan full of ashes and a scoop, seemed to work well. I wish I'd had your soil and the hope of a point somewhere in there  .

An apple tree near the old homesite is oftentimes the site of an old privy here. I found one of the old pits on our place when I dropped into it bushogging, they had rolled every big rock in the area into it. It now has a nice gravel layer on top of the smaller boulders and I have a rebuilt gearbox  .

[hpinson]

Don_P, I think we are going to have apples this year.  The trees that were in bud two weeks ago, and swarming with bees, now have hundreds of little fruits.  I can't imagine that happens too often at 7800'.     There are some indications around the tree that there may have been structures there in the past.  No obvious outhouse pit though.

Anyway, I continued working on the outhouse this weekend-- and what a nice weekend too.  Cool, with high clouds keeping the temperature just right. 

The project was to build the concrete forms for the outhouse footing, and pour the concrete.

There's plenty of old low-quality wood around from various demolitions underway, to use for concrete forms. These were from the collapsed barn nearby. I used a mix of motor oil and kerosene for the release agent for the forms. I hope it works.

Here are the forms in place, strengthened with a little rebar.



Poured the footing concrete 5" wide x 6" deep.  I had forgotten a trowel, so had to make do with scrap 2x4 to smooth the surface. Good enough I suppose. At least it's level, if not pretty.



I finished at 6PM, went for a walk, and met some of my neighbors.



Sunday morning I wetted everything down to cure, cover the footing, and that will have to do until I return.

[hpinson]

Oh... John... you could make a fortune selling some decent outhouse plans!   

[MountainDon]

So could you 

Do ya' need a manager? 

[hpinson]

Continuing with the outhouse build...

We pulled the forms off the concrete with no problem. A mixture of old motor oil and kerosene does in fact work well for a release agent.  After doing this I noticed that my foundation was not quite straight on one side.  Just cosmetic, but I learned something. However it is level.



Should I paint the concrete? Will it last longer if I do? Does anyone have any recommendations?

Bolted treated wood 4x4's to the foundation on galvanized bolts set into the concrete. The 4x4's are set in caulk.



And on top of that, we started the post and beam frame made up of 4x4 cedar posts.  Not quite sure why I'm framing this way except I had some of these posts lying around and it seemed a good use.



This was taken right before the third thunderstorm of the day started up, with hail!  Odd weather... nice to work in though... it's much cooler and wetter, thankfully, than this time last year. Waking up at dawn with a huge thunderstorm was a real surprise.



It will be a few weeks before can continue, so I nailed a temporary triangle brace at the bottom which steadied everything up. Don, I learned something!

All is not well with the well... pump however.  More on that later.

[MountainDon]

Nice.

Paint? Only if you want to repaint it in the future.  I wouldn't.

I'd find some really nice SW motif tile and install that around the perimeter.   

               probably not   

[hpinson]

[Moved this to my build thread from the off grid power thread.]

I'm wondering if I could get some opinions? My direct PV solar panel is not pushing quite enough amperage to efficiently run a DC well Simple Pump motor and suck water from 180' static.  It does work in the afternoon full subshine, but at about 11 amps, the motor only pulls about 0.25 GPM at best. Any small puffy cloud stalls the motor, and often I have to manually assist to get it restarted when the sunshine returns.  The addition of a Linear Current Booster is essential, or the motor will not run at all under the load.  The pump manufacturer has stated that the vendor speced direct PV system is not quite up to the task.

Optimally I want to get 0.5 to 1 GPM output, which is the old well's rate of recharge, be able to run the pump througout the day, occasionally at night, and maybe have a 24 hour charge cushion for the rare cloudy day.  Weekend cabin usage mostly.

Some background.  The panel is a Sun Electric fa3c, with the following ratings listed on the panel:

B Grade
210 watt
Pmp is 12 volt
Vmp is 18.30
Imp is 11.48 Amps
Voc is 22.80
Isc is 12.11

Orientation is due south with a 35 degree tilt for Santa Fe, NM lattitude. I could probably gain some output by summer adjusting the tilt to 20 degrees, but (I think) amperage output would still be marginal at best.  I believe to pump this load at a rate of 1/2 - 1 GPM, the motor needs close to 15 amps.  Temperatures range between -30 in the winter and +105 in the summer. These are extremes.

I think I need to add a MMPT charge controller, remote temperature sensor, and battery to the system, which will look like this:

210W 12V Panel > 4' MC4 Cable 10GA > 8ft MC4 Extender Cable, 10GA >  Midnight Solar Combiner/Breaker > 6GA x 18' cable > MPPT Charge Controller + temp sensor > AGM Battery(s?), 12 Volt > Disconnect > 3' 10GA Cable > Pump Motor

I'm condsidering a Morningstar SunSaver 15 Amp MPPT Solar Charge Controller

http://www.solar-electric.com/mosumpsochco.html

And a single Concorde AGM Sun-Xtender sealed deep cycle battery:, Ampere Hours @ 24 Hour Rate: 104 Ah

http://www.solar-electric.com/pvx-1295.html

I'm very unsure if I am making the right selection for charge controller and battery. Can anyone comment?

[UK4X4]

Solar systems always have losses- whats on paper is rarely correct

Need your expected load and hours of usage to get it sized correctly

ie X amp/hours

Your panel puts out 11.48 amps- take 5.5 hours of sun per day (use a sun map it may be more)

That gives you 63 amp/hours from your panel so if your pump wants 15 amps you should be able to run it for 4 hrs a day.............that gives you no spare power for the cloudy days and if 4 hours is not enough then you need to look at more panels

15amps is a hefty load for a solar system

So if you wanted to run the pump for 12 hours every day it goes like this

12 x 15amps =180amp/hours per day

you have roughly 5.5hrs per day of sun

180amps /5.5hours is 32 amp/hours

32 amp hours / 11.48 from that panel =2.8 panels required to power the pump for 12 hours- then you need to look at the batteries and charger to suit that
So you would need

[hpinson]

Thank you-- that is very helpful. 

So lets say I want to pump for 12 hours a day (which is overkill but lets assume).  The motor amperage requirement is really more like 14 amps at max torque, which I am close to.

12hrs*14A = 168AH

An AGM battery that seems to meet and exceed that requirement (for colder weather) is this:

http://www.solar-electric.com/pvx-12210.html   

which is rated at 212 AH.

Does that make sense?

[UK4X4]

If only things were so easy !

Batteries are sized for their max capacity - but under normal working conditions you don't want to go below 50% of discharge even if its a deep cycle.


This gives you a nice work through

http://www.wholesalesolar.com/battery_sizing.html

14-15....amps thats where calculations and actual differ- there's so many losses in a solar calculation you can do it 60 times from 10 diferent websites and you get a diferent answer everytime !


Note the theoretical max power of your panel at 12V is 17.8amps..............not 11.28- thats at the max voltage- my mistake

So really 32 amp hours / 17.8 = 1 .8 panels to provide the power for 12 hours operation.

Do you run with a water tank ?

as if you add in a timer you can control the usage per day, and a float switch to conserve power when the tank is full.

In the field where I work I have in the past chipped off every amp I could.....later I was adding batteries and panels............

If you want it to work reliably under normal conditions size generously

[hpinson]

Great answer UK 4x4-- you asked the right questions and it really helped.  It took a while to come to terms with what I really need in terms of battery capacity, and in the process I changed how I envision the pump should operate.  Also, getting my head around the sizing calculations took a while! 

The most insightful question that was asked was how many hours a day will the pump run?  My initial take was that I should have the battery capacity to fill the 500 gallon tank in one or two runs, but in reality there is no need for this, and such capacity not fiscally feasible for me.

Instead, I will pump for an hour every day, DC timer controlled, and trickle fill the tank.  Since usage is three of four people on weekends, with no flush toilets, I think this should more than suffice. The tank will be fitted with an overflow outlet, which will feed a small stock tank which presumably will attract wildlife.  This has the added benefit of keeping the water in the tank fresh.

Using figures provided by the Simplepump manufacturer I determined that the DC pump motor uses about 17.8 amps per hour (like you said) pumping 0.5 GPM from 180 ft static. Multiplying that by twelve volts gets 214 Watts per hour or 430 watts per day. Lets say I will pump 2 hours a day (higher than I really think I will need) which should be about 60 gallons.  I'd like two days of battery backup in case of clouds. We are in a sunny place and two days of cloudy weather is rare, but I still used a conservative figure of 4.5 hours of sunlight per day. Operating temperatures with be 20F to 100F, but the battery will be housed a small ventilated underground box, which should even out the temperature somewhat.  There will be no deep winter usage that I envision. I'm assuming 50% max drawdown on the battery and then the charge controller should force a device disconnect.

My single solar panel is 210 watts (Pmp) 12V, has a voltage at peak power of 18.3V, provides 11.48 amps of current at peak (Imp), has an open circuit voltage of 22.8V (Voc), and a short circuit current (Isc) of 12.11A.

I used this helpful panel and battery sizing calculator: http://www.batterystuff.com/kb/tools/solar-calculator.html (and double checked with the one you suggested).

Given these parameters, a single 12V 104 Amp Hour (AH) Activated Gel Matt (AGM) battery (20hr discharge rating) should suffice. That makes me happy because the larger AGM batteries are quite pricey and heavy.  The AGM battery seems low maintenance and tolerant of temperature extremes, though probably will not last as long as watered 6V deep cycle golf cart batteries, but I don't really want to deal with the watering and corrosive off-gassing.  Cost is about $300 with shipping.     

If the system works well, and I need more battery storage, I can always up the size of/ replace the battery array later.

I'll use a Morningstar PVM ProStar 30 Amp, 12/24 Volt Solar Charge Controller With Digital Meter, which is under $200. It accepts 6GA copper which is good. The 20 Amp model no longer seems available and 15 is not enough.

I can't really justify the great additional cost of the MPPT controller. I was told I really don't need MPPT in a system this small, though I really don't understand why it would not be of benefit (much like a Linear Current Booster). Regardless, I'll go with the PVM.

Pump timing automation will be achieved by use of a Flexcharge DC timer running off the battery, and a relay-- because the Flexcharge timer cannot handle the 17.8 max amps directly.  I did look at a Morningstar SunLight SL-20L charge controller with a built in timer, but the timer operation really was oriented towards night-time lighting control, and was not very flexible.

I'm hoping total cost will be under $600.

So how does all this sound?

Here are the calculations. I think I used 210 WH instead of 214 WH, but the result is similar.