outdoor shower drainage

I am getting a lot of different opinions from different folks about the importance of drainage for the outdoor shower we are planning. Advice ranges from "don't worry about it, the water will drain" to "dig a huge hole and put in French drains and it's probably not legal to do it anyway so don't"

The soil is pretty well draining. The shower will be near a part of the house that has a crawl space instead of basement. It will be away from the house by a few feet. I'm planning to have a cement slab under the shower and build a floor below and walls around with some ipe decking I have.

Dig a hole/trench and fill with pea gravel? I'm going to plant comfrey all around the drainage area.

So what did y'all do for your outdoor shower drainage? And how did it work out?

Here's the preliminary pics of my outdoor shower (designed by and workshop lead by water harvesting guru, Brad Lancaster - 2008 )

Three drains each venting to a separate, armored infiltration basin.





The cement pad



The shower integrated into the shadehouse on the east side of my house. The shadehouse also includes the propagation area, the hen yard and two compost bins.



So questions:

1. Do you know what your soil's perc rate is? (have you done a perc test?)
2. How many showers do you anticipate will happen per day and for how long each?

With those two pieces of information you can figure out how much square footage you'll need to soak your greywater efficiently (you don't want greywater sitting around on the surface). Err on the side of too much as opposed to too little.

Oh, and the way I was taught is that you don't use French drains for greywater - only rainwater. I know people HAVE used French drains for greywater - but this is the info I'm getting from people whom I consider to be experts like Brad Lancaster. I think Art Ludwig says this too but I honestly can't remember.

Hi Matu,

Matu wrote:The soil is pretty well draining.

Most soils do, even with a little augmentation of sand and/or gravel. Perk testing can be done, yet typically is only a need when doing soil studies and large scale septic engineering.

Matu wrote:The shower will be near a part of the house that has a crawl space instead of basement.It will be away from the house by a few feet.

Just make sure that you dig down to mineral soils and slope AWAY from the crawl space. This is typically more than enough. As for french drains (or piping of any type) unless you are doing some type of "water treatment" or other "water management" activities drain pips are just an added expense. If you do want to channel water to a very specific location, this is the only time piping or channeling of any type is needed. I have used everything from old clay pipe to traditional "reamed wood pipe" (which we still make locally and have the tools for it...which are still around if you look) and these wood pipe will work for as long as a century depending on species of tree used. Wood pipe was normally used for potable water not waste water...so life span is reduced unless you employ a species like cedar, cypress or the related "none rotters." Then again, you get drainage and "hugelkultur" all in one with this system.

Matu wrote:I'm planning to have a cement slab under the shower and build a floor below and walls around with some ipe decking I have.

Concrete?...why?...(sorry for those that love this stuff) This is an added expense, support a horrid industry, and just simply is not necessary for what you are designing and asking it to do. There are countless design modalities that outdoor bathing features can take. From all stone to cobb, to ceramics, to tadelakt, to timber frame and a mix there of... I see so many "wood post stuck into concrete slabs" that within no time rot right off and the concrete irritates the feet. If you do a wood floor it can be looked at as "sacrificial" or you can design in such a manner that it is VERY self draining.

Matu wrote:Dig a hole/trench and fill with pea gravel? I'm going to plant comfrey all around the drainage area.

Not much more complicated than that...and some log cooky rounds to stand on...add a screen...call it done and beautiful...

Regards,

j

Yep...doesn't really have to be complicated to work well for decades (or even longer.)

Hi Matu:

I have been living on a remote island for 17 years now and I have two outdoor showers. In both cases the water simply drains through the slatted wood floor onto the ground.
I probably average just less than one shower a day which would be about 5 gallons of water, maybe a bit more, each time.
There has never been any issue with drainage, odor of any kind, nothing.
If you like I will take some pics tomorrow so you can see what's here. Just have to figure out how to post them...shouldn't be that hard.

Keith

Keith...thanks for adding that! Photos of your site and design would be great!

Regards,

j

I have made plans to build an outdoor shower, but have not actually done it. I always envisioned doing the floor like the picture on this link, cedar planks over gravel.

Keith, do you drain your shower onto bare ground? ground cover plants? Gravel?

Since the area will be well watered it seems you could plant some herbs and stuff that would smell nice while showering. Maybe even some naturally cleansing plants that you could break off and use in the shower too.

OK...here goes. Bear with me for a few minutes as I get the photo thing worked out.

I will try and post firstly about the original shower followed by the newer one which I use presently.

I see we are limited to 3 photos per post. So what we have here are simply three views of the outside of the original shower. This one has been in place for about 15 or 16 years, and even though there is no pressure treated wood used anywhere it is still in one piece!

When we first arrived here to an overgrown lot, the first thing done was to put up a small (temporary) cabin. Following that I built the first part of the new house, which was to be used - eventually - as a studio. Initially it was used as a storage room so that we could move our stuff from a storage locker over on Vancouver Island and avoid forking out $80 a month. The shower was then attached to the corner of the storage room.

As you will see, whatever limited water was used with this shower drained through the floor and fed whatever plants may have been close by from time to time. That big old fern that you see has been there for many years now and seems to survive whether the shower is used or not. I don't think it has seen any use for two or three years now.

You can see that I put an old 30 gallon water tank up top which I salvaged from an old boat. On warm summer days the sun used to warm the water reasonably well as I painted the tank black.

There is a home built solar collector on the roof of the studio, and at one point I used a bilge pump motor (again salvaged from a boat) to move the water through the collector. This was only moderately effective because I don't think there was enough collector area. But, what the heck, better than nothing.

In order to get water into the tank, I rigged up a garden hose to a long stick and poked it into the hole at the top of the tank. Pretty crude, but effective.

The pics show the open slatted floor and the copper plumbing which gravity fed the water to the shower head.

Great Job...I love it!

Moving now to the newer shower, which I think I built around 3 years ago, it is much less funky but works extremely well. This one is even usable in wintertime, although one doesn't want to linger around outside when the air temperature is freezing!

This one has a roof, a full height window to look out over the water, a crab cooker to heat the water, a small electric pump (110v) to move the hot water from the cooker to the shower head and the usual slatted floor for drainage.

I generally put about 20+ liters of water in the cooker at a time. It only takes about 7 to 10 minutes tops to heat the water. Yes, I do realize I'm using propane, but it is so nice and handy to be able to have hot water in just a few minutes any time of the day or evening. Sometimes the water gets too hot, so I just add some cold to temper it.

From inside the shower there is a terrific view over to Vancouver Island.

I tried to get a shot of the shower head, but I think it might be too dark to see properly.

The last pic is of the wall between the deck and the shower area, which completely hides that area from the rest of the property.

To close this out here's a few pics looking at the front of the shower room. Well, actually, the first pic shows the door which one gains access to the shower from the deck.

Zach Muller wrote:I have made plans to build an outdoor shower, but have not actually done it. I always envisioned doing the floor like the picture on this link, cedar planks over gravel.

Keith, do you drain your shower onto bare ground? ground cover plants? Gravel?

Since the area will be well watered it seems you could plant some herbs and stuff that would smell nice while showering. Maybe even some naturally cleansing plants that you could break off and use in the shower too.

Hi Zach: Sorry but for some reason I managed to miss your post.

Yes, the water runs through the shower floor(s) onto the ground. Here, there is very little soil on top of the bedrock which forms the island. At the new shower there is likely only a foot or so of soil, which is mostly broken down sandstone. The water drains immediately and there is NEVER any standing water anywhere here. That also applies when it rains. Even when we get a real deluge you do not see any standing water. That has actually been somewhat of a problem with gardening here, as the ground doesn't want to hold much in the way of moisture.

But when you think about it, 20 or so liters of water every day or so isn't that much water.

I think the pics will give you a good idea of the present setup.

I do have an old dinghy in the garden which is packed full of herbs. I can't even begin to keep up with all the production from this little boat!

Very cool shower Keith. It looks nice and tranquil there where you are. Thanks for all the pictures.

Even though you are using propane I like the use of the crab cooker to heat the water. How many showers does a fresh tank of propane last?


Don't let your herb bed sail out to sea!

Zach Muller wrote:Very cool shower Keith. It looks nice and tranquil there where you are. Thanks for all the pictures.

Even though you are using propane I like the use of the crab cooker to heat the water. How many showers does a fresh tank of propane last?


Don't let your herb bed sail out to sea!

You know Zach, I'm really not sure how long one 20 lb. tank lasts. But it does a huge number of showers. In all the time I have had the shower in use I think this is only the third tank in use.

The secret seems to be in getting the setting right at the burner...not too much and not too little flame. And then use about 20 liters of water to heat and if it gets too hot just temper it with some cool water. It's a sort of balancing act. The cooker has an automatic timer on it which shuts the burner off once the timer expires. So if we are having a hot summer day, the water in the cooker will start out at 75º or 80º and it takes but a few minutes to heat up. I have a cooking thermometer in the lid of the cooker so I know just how hot the water is.

The other thing is that it is outside and subject to getting leaves etc. fall on and around the cooker. About once or maybe twice a year I take the top off the burner and clean it out. There is just one small nut that you undo, lift the burner head off and clean it. Takes just a couple of minutes, so it isn't an onerous job by any means. You can always tell if there is any debris in the burner as the flame will start to go yellow...then it's time to clean right away!

I love the great showers ideas in this thread. Just one question - what are your thoughts on multiple showers (like in a situation like a campground type of scenario where you have more than one shower) - the ontario (canada) building codes etc, require a septic tank even if it's for greywater where no chemical based soaps etc are used. Just wondering if there is a more sustainable way that would be accepted by building codes instead of having to spend a lot of cash on a huge tank just to hold greywater... thoughts?

Vida: Ontario isn't the only place that wants septic tanks for using a glass of water! Some of the requirements are really ridiculous.

However, I can see in the case of a campground such as you are suggesting that a septic tank might be in order. One or two people using a shower...OK. But 50 or 100 every day would be another matter. I don't have the magic bullet answer, but I will be going through this scenario next year on a lot I hope to buy up at the North Shuswap in B.C. Even if you use a composting toilet - which I think is an excellent idea - (been using them for 17 years now) they still want a full blown septic system just for relatively small amounts of grey water.

Costs to install that I have been quoted from 10 to 15 thousand dollars. A bit rich for anybody's blood if you ask me.

Hey Keith, thanks for answering. I was afraid that would be the case! And yeah the requirements & cost is really insane and limiting.

I wonder if the grey water can still be used, even from the septic tank. Compost toilets are in the plan too for sure, and are definitely my preference. I'm trying to weigh up if it's worth just getting a septic tank that can hold both grey water and human waste though just to see it from all angles. But I'm guessing the price would be even worse.

Good morning Vida: Regarding the septic systems...my next door neighbour here is a contractor licensed to install septic systems. We had a lengthy chat a short while ago about the requirements and how one of these installations goes. Here in B.C. our lovely government has very specific size requirements for both tanks and field size. It isn't actually the tanks which are that costly, it is more the installation of the field. And it depends on whether or not you are able to use a gravity system or if you need a pump. These pumps I am told run around $500 and the tank (750 gallon size in my case) about $750. Looks like about a dollar per gallon. And for a small system here, I will need 180 lineal feet of lines in the field part. Typically, that would mean three runs of 60 feet. They base your size requirements on how many bedrooms you have in your dwelling.

If you can use a gravity system, the overall costs will be less. You would not need to run electricity to the pump for example, so one less cost.

I think if you do a search under your Ontario government building regulations that you might find a whole set of instructions as to how a full septic system goes together. It isn't rocket science, but here in B.C. they can only be installed by licensed contractors. The course that Steve (my neighbour) had to take cost him $8,000. Maybe that's why there aren't too many with such a license.

As for using the septic effluent in the garden, I'm definitely uncertain about that. However, using the composted matter from the composting toilet I have no problem with at all. If you go to the various websites run by the compost toilet manufacturers, you will see that they all suggest that you can use the compost for your garden. I can tell you from experience that it works!

Have a great Canada Day!

Thanks Keith for all the info. Really helpful! I definitely think the gravity system would be better as well. My personal property has to use a pump to get the effluent uphill and it's sort of a drag. An extra thing that can break

I have a feeling it will be a similar story here in Ontario in terms of tank size etc. The septic system is going be set up for a property that wants to run like a commercial campsite and so in order to even get the zoning has to have this septic tank installed, even if it's just for grey water. A bit irritating although I'm sure there are sound enough reasons for it.

What is your opinion on the old debate of growing food near leeching beds/septics? If there is another thread on this feel free to point in me in that direction as not to distract from this one

Happy Canada day to you sir!

Hello again Vida...spectacular day here on the we(s)t coast.

You know, I have never given any thought to your question about the growing of food near a septic leach field. I think before I would try something like that I would check out just what the effluent might be like once it exits the tank. I really have no idea if it could be toxic in any way or not. My hunch is that it shouldn't be toxic, although I really have no basis in fact for saying that. Just look at some of the stuff that gets sprayed or spread on commercial food production farms...I hardly think septic tank could be any worse.

I understand that there might be a problem with growing plants there, by virtue of the fact that the roots will want to seek out the wet ground and could possibly clog up the system.

Steve was explaining the system to me where a one inch plastic line is used and 3/16" holes are drilled every 3 feet in the lines. I think this refers to a system using a pump. I suspect you are thinking of the old systems where you use tile in the leaching field, or perhaps big "O" pipe, and presumably that would be perforated.

Hey Keith, just got some interesting news. I found out from a building inspector in the area that we don't need a septic tank for grey water! We just need to have a filtering system for the water which is approved by an engineer. Kind of interesting!

Oooo, that sounds good. I wonder if there is such a thing up at the Shuswap,, I'll need to check into that when I get up there. Many thanks for that little tidbit.

yeah for sure. All the best with that! Here is the ontario regulation, FYI gives a diagram as well: http://www.kflapublichealth.ca/Files/Resources/Class_2_Systems___Greywater_Leaching_Pits.pdf

Hi all,

I'm new to this forum - very appreciative for the content and effort by all of you!

I've done a solar outdoor shower before, but now have a new project that requires a different approach for drainage... this outdoor shower will be our only one (my partner, myself and 2 year old son) and we're discussing whether or not we should route it into the septic system we're installing.

The septic design has a single toilet (1.6gpf) going into two 55gal drums which are tied together. The second drum will have a baffle for draining the liquid waste into the drainfield, which consists of 20 ft of "gravel-less chamber", a substitute for gravel filled trenches that seems to be more effective.

The property owner, a good friend of mine, has suggested we route the shower water into the 55gal drums along with the toilet water - in other words, send the black water from toilet and grey water from shower through the system together. He feels like this will cycle it quicker and help with decomp process.

I suggested keeping them totally separate - and simply digging a big cone-shaped hole, filling with pea gravel or washed rock, then letting it drain naturally while planting some thirsty plants around it. When he suggested tying it into the drainfield (which is about 20ft away from the shower location, so totally feasible), I felt like it would be better to keep the soapy gray water out of the solid waste drums and tie it into the drainfield after the drums... Hope this is clear.

Any input? Will the high water volume from the shower help the solid waste decomp, or hurt it? For what its worth, we only plan to use bio-compatible soaps.

Thanks!

Hi Nicky...Welcome...

I second your view of this...

I personally do not like "mixing" gray and black unless part of a pretty complex (usually greenhouse based) full on plant and animal based treatment system that may include everything from "mechanical grinders and agitators" to UV sterilizers...All of this assuming that I even would ever choice to use a "water based" system to treat "black water." I have become a very strong and avid proponent of dry composting systems over most of the "water based" sewage treatment modalities...

Your design and thoughts (or something similar) is what I would recommend...

Me too. Black water systems function better when flow is modest. Increasing flow costs more. Your plan will be quick and will cost very little. If it clogs up in 20 years, dig it up, wash the gravel and put it back.

Thanks! Very appreciative.

Just to contribute, here is a photo of the shower I did while living in Costa Rica... drainage was easy as we had a trench already dug for the massive rainfall... Solar heat via a big roll of poly pipe up on a metal roof (sucker got HOT!!).

Hello

I am building an outdoor shower.  I have a waste line ready that's buried.   I need a trap and some sort of pan/catch/concrete slab pitched to a drain.   I am not sure what to do.  Any suggestions on what to use: a shower pan, catch basin (probably not) or concrete slab with a drain?  (Sorry new to the forum-should I make this its own thread?)

J

We just moved to our property in TX over Memorial Day and for the first 2 weeks we were driving to the truckstop (80 miles each way) every few days for showers. We had a 16×40 building delivered to use as a cabin until I can build our house. Because space inside was limited (we came from a 2500 Sq ft house and even after filling a 20yd dumpster there was still a lot of "have to keep" stuff) I decided to build a shower outside. I built a platform with 2x4s with 1/2in spacing in the deck. It measures 40in x 60in. Because my nearest neighbors are 1/4mi away, had it been just me I would have called it done but mom would never go for it so I used 2x4s to build a frame and my sister's landscape cloth to close in all but the roof which we left uncovered. I put in a low flow shower head to help conserve water. I was figuring 25 gals of water per shower but with that shower head we are barely using 30 gals for all five of us. We pump it from an IBC tank. If you want cold shower take it in the morning hot in the afternoon or warm in the evening lol. The soil has a lot of clay so the water doesn't sink right in. My sister noticed that it flowed down along the building so she added gardening soil there and now it sinks in and the squash love it. We don't allow most chemicals on the property so our soaps and shampoos are all natural and will not hurt the plants.

Hi, I’m writing to urge you to not let water drain into your crawl space. I am working on an outdoor shower because I live in a tiny cabin without running water. I live here because the house I lived in previously had poor drainage for rainwater and the driveway has a slight grade that drained water into the crawl space. Long story short: it developed a serious toxic mold problem, my health suffered and we had to demolish the house. So I’m begging anyone who will listen to keep your showers away from the side of your house unless you really know what you’re doing with the drainage system. I want to spare you the nightmare I’ve had to deal with.