A couple months ago I put in a greywater system at my home,
actually a pretty aggressive greywater system. Most people just do laundry,
where their washer will run out to somewhere,
some sort of basin and water some ornamentals in their garden.
Where I actually took both the laundry and my shower system and routed them both
out into the garden.
So this video is an update and answering every question that you guys asked on
that video. So if you're thinking about doing a greywater system,
which I think will be a very smart investment in the coming years,
just pretty much globally, this should.
Answer everything you need to know.
Side note. If you haven't watched the initial install video,
I highly recommend it because some of these questions are kind of specific to
that system. So go watch that, I put a link up there,
then come back to this one and it'll make a lot more sense.
The first question is the most obvious question and it is what's the full cost
and return on investment breakdown? So I have all the numbers here for you.
So first of all, let's take the shower.
We did the math and I'm using roughly 88 gallons a week of water,
about one shower a day.
That ends up being 4,600 gallons of water per year out of the shower.
And then the laundry, it's about 20 gallons a week.
I have a pretty high efficiency laundry system. So 20 gallons a week, maybe one,
maybe two loads per week equals 1,040 gallons a year.
You sum that up and you're looking at it's something like 5,700-5,800
gallons a year of water that's being rerouted out into the orchard and
into the artichoke patch. Now, how much did that cost?
The install cost - $2,300.
It could've cost less and it would cost less if you did it yourself.
The laundry system itself maybe cost 500-600 bucks.
I had labor from Brook of Catching H2O, who was very helpful.
I also had a grant from the water authority that made it a little bit easier to
justify the labor. But let's just run it at my cost, okay. So 2,300 bucks,
that means the total cost per gallon in the first year is about 41 cents a
gallon. That's pricey for water. That's actually pretty pricey for water.
That's almost bottled water prices. Now, if you spread that over 10 years,
which is at least how long this system will run,
you're looking at 4.1 cents a gallon, which sounds cheap,
but it's still not that cheap. The reason why is because I pay, get this,
for 100 cubic foot of water - 748 gallons I am
paying 0.006 cents per one of those gallons.
So 0.006 cents for a gallon of water at a medium tier of
use.
So it's still eight to 10 times more expensive to run this greywater system.
So like I said in the initial video, from a return on investment perspective,
just the numbers, it's not intelligent. But you have to think about this.
Number one, you're alleviating a lot of the use on the sewer system,
which is just sort of a good thing to do in general. Number two,
water is probably not going to be that cheap for that long, right?
So you have to price that in. The next most common question is,
can you use greywater on a lawn? And I think the answer is technically a yes,
but it's a highly recommended no.
And the reason why is because you don't want to use greywater anywhere that your
pets or people, your children, yourself are going to interact.
Lawns are meant for people and pets to enjoy.
You typically want a greywater draining out above ground into some sort of mulch
basin. And it's just not a great use to put it in a lawn.
The next question is really common.
It's can you store your greywater for the long-term? The answer is just no,
you can't do it.
The reason why is because even if it's coming out of your laundry,
but especially if it's coming out of your shower, there's bacteria in there,
it's not clean pure water. It is greywater.
And so that's going to go foul. It could go putrid.
It could go anaerobic if it's sitting in a tank for a long time.
There are ways to clean and process greywater and then process it for long-term
storage. But the effort and the cost is just like way,
way more than it's worth. You're spending too much money. It doesn't make sense.
Just do rainwater capture, which I have a whole video on.
Use your greywater immediately in a flood irrigation style setup.
The next question is then,
well can I use greywater in an irrigation system like my existing drip or
sprinkler system? Technically again, yes you could.
But there are like three reasons why you wouldn't want to.
So the first would be your showering. You've got dirt on you. You've got clods,
little bits of whatever - you don't want that going into your irrigation system.
Cause if you hooked it in it would go straight into those lines and it could
clog up your emitters or your sprayers or whatever. Number two,
you'd have to pressurize the greywater before it entered the system, right?
Because irrigation runs on a pressured line. So that's a hassle,
it's extra cost. And then third, at least in California,
if you're going to put it into some sprinkler system you actually can't spray
greywater airborne. It is not recommended, it's against the code.
So you still wouldn't want to do it. It doesn't make a lot of sense.
So for the laundry system there's a question about can I just do a DIY system
where I just hook a hose up to my laundry washing machine? You can do this.
The reason why greywater works with laundries especially well is because laundry
washing machines already have a built-in pump.
And then that pump is going to push it out to wherever you're deciding to
irrigate. So some people will say, okay,
well then I'll just use a hose and I'd be fine. Well,
the reason why you don't want to use that is because the pump has to be matched
to the correct diameter of the pipe.
So you typically want to use a pipe that's at least an inch in diameter.
The one that I have from my old video,
you can see it's much bigger than a standard hose.
So what you'd need to do then is use the correct size pipe and then size it down
to like a three-quarter or a five-eighths inch.
Whereas at that point you might as well just put in a standard greywater system
like we did in my video. Okay,
the next question is what if you have a high efficiency washing machine,
cause you're trying to actually save on water in general?
It doesn't even make sense to do laundry greywater. This is a pretty good point.
Sometimes it doesn't make sense.
Really efficient washing machines can use like 10 to 15 gallons.
So if you do a load a week, you're looking at maybe 500-600 gallons a year.
And at those prices that we talked about for that many gallons,
that's like less than 100 cubic feet of water - HCF,
which is the measurement standard. So it's really like dollars at that point.
So then you say that's not really worth it. Well, technically financially again,
no it's not but there are a lot of good reasons why you would want to do it that
we talked about in the initial cost breakdown question.
Far and away the most common question that you guys all asked was what
detergent should I use? What soap should I use? What body wash should I use,
shampoo? All of those types of questions. Do I have to switch the detergent?
Even if I do, is it safe to use in a greywater system?
So I asked Brook from Catching H2O to give me just a complete list of
all the approved ones that she knows, she uses, she loves. So first,
what do you want to avoid in any sort of soap or detergent that you use? Salts?
For sure. Boron, not great.
Not really bad for us as people but not great for plant use. It's just,
they're not going to do that well. Then chlorine bleach is.
Avoidable. You want.
To avoid it.
It's technically not the worst thing in the world but you do want to avoid it.
And then bar soaps, typically over liquid soaps, will change the pH.
Much more. So avoid bar soaps.
But let's go through the laundry list of laundry.
Detergents and soaps. So we have in the laundry list,
the one I use is called Oasis laundry detergent. It's hyper,
hyper concentrated and it actually tells you what it breaks down into,
which I'll put up on the screen for you. Next, you have ECOS, E-C-O-S,
liquid detergent. You can use that one. Vaska scent-free laundry detergent. Fit.
And then a lot of people like to use what are called soap nuts.
So you can check those out as well. Everything will be in the video description.
In a sink situation,
remember my shower also has my bathroom sink plumbed up to the greywater.
So you can use Oasis bio-compatible all-purpose cleaner,
but then Dr. Bronner's as well. So I like Dr. Bronner's.
I went on a trip in New Zealand,
I used like a tiny little bottle of Dr. Bronner's for the whole trip.
Might not have been the most sanitary thing in the world. Nevertheless,
you could use Dr. Bronner's for your greywater system.
When it gets into the world of body wash or just whatever to use in the shower,
Aubrey Organics is good. Avalon shampoos is good.
Burt's Bees has a couple good products, not everything is great.
And then Dr. Bronner's. So for me,
I go with Oasis detergent for my laundry and then I just go with Dr. Bronner's
across the board for anything that has to do with the bathroom.
The next question then is okay, well maybe if I switch,
something will still happen to the soil and specifically the soil life.
The only real issue you're probably going to have is if you have clay soil,
the particle size is too small in the clay soil.
So you still might get a little bit of a salt buildup in that case.
You'll know by looking at the soil. So you can dig out your mulch basin.
You can look, if you see a lot of white buildup,
just grab fresh water and rinse it through and you should be able to rinse those
salts out. But with clay soil,
it still can be a little hard because they don't have anywhere to go.
The particles are too small, they can't fit, right?
And so what you can do is dig the mulch basin out.
You can incorporate some compost or eventually that mulch basin will break down
and it'll become compost. And that actually brings us to the next question.
So the next question is when I run the system, do I need a mulch basin?
What's the mulch basin good for? Cause if you remember,
both in the shower system,
we dug out these big trenches that irrigate four trees each, at least right now.
And then we dug out a little sort of smiley face in the artichoke patch with
three outputs that are buried by mulch.
And so what's happening there is just a classic wicking situation.
What happens is the water will drain out of the shower or the laundry,
it'll go into that basin, hit the bottom where the soil is, right.
And it's not draining right away.
So what'll happen is as the shower or the laundry runs,
water will run out of that system into those basins.
And then some of it will drain into the soil right away, which is what you want.
But some of it will sort of pool for a bit.
And that's where the mulch comes into play. Because if the mulch isn't wet,
it'll start wicking that water into the mulch and spreading it around the entire
mulch basin.
Basically sponging up that water and then dissipating it into the surrounding
soil when the soil is able to accept it. When it needs water.
So it's a great use for that. But then the follow-up question to that is, well,
if that's happening,
if I'm using an organic mulch next to the soil and I'm adding water and
eventually no bacterial microbial life, fungal life is going on,
won't the mulch just break down? And the answer is, eventually yes.
So typically what you want to do is take a look at it and look where the actual
irrigation valves are and see if it's breaking down and starting to potentially
clog those.
That's why you have those green irrigation boxes that you saw on that prior
video that I did,
because that prevents any buildup from clogging those outlets.
We had a question about can you install a greywater system in a slab on a grade
situation? So yes and no.
If your laundry system is close to an exterior wall,
then yes because you can go through the wall.
If your shower is on the first floor,
then no unless you want to jackhammer out the slab,
which I'm assuming you probably don't want to do unless you have some sort of
other renovation going on.
But you could do it on the second floor because that's not on the slab, right?
And so you could route a shower greywater system through the second floor,
down through an exterior wall and then out into something else.
But as far as a first floor shower or a laundry that's like in the middle of the
home, it might be a little tricky. Really common question,
how do you know how much water you are getting out of your systems and then how
much water the plants need?
So how do you like design a system for the amount of trees you want to irrigate
or the amount of bushes, right? So just for example, let's take mine.
My laundry system is putting out about 15 gallons,
20 gallons a week if I'm doing one load a week, right? So 500 gallons a year.
So then you just want to look up, okay, 500 gallons a year.
What am I trying to grow? Artichoke.
What you can do is just Google artichoke irrigation needs.
I would say irrigation, not watering,
because when you type in irrigation you're going to get farming calculations,
which will give you a better estimate.
Because they really have to be on their game. And so I did that with my citrus.
I did that with my artichoke and I said,
okay well I'm actually well under the amount that those plants will need when
they're fully mature over the course of a year.
So it's more a question of how many can I reasonably even attempt to
irrigate rather than am I going to overwater? I think maybe my citrus early on,
I might be overwatering. But man, as that citrus hedge starts to really ramp up,
my showering is really not going to touch the amount of water that they need.
Cause they're gonna be very, very mature. Next question is,
can you overwater your trees? Like I said, you can for sure,
especially early on in their life. But if you think you're overwatering them,
all you need to do is go check the soil where you're irrigating. And if you are,
you flip your switch in your shower or your laundry system to go back to the
sewer for a little bit,
to let that water actually be used by the plants before you reirrigate.
So you have full control on whether you are using it as greywater or whether
you're just using it as a normal shower or normal laundry.
Can you use dishwasher or kitchen sink? I actually asked Brook this,
of Catching H2O. I said, can we just do it on the sly and like tell no one?
And she's like, you really actually don't want to.
As soon as you're using the sink water, you've got oils, butters,
like weird stuff, weird combinations going down, clogs can happen.
It's just not a good idea. And setting up a whole filtration system is again,
more cost than it's worth. Dishwasher, same idea.
You just don't want to use that stuff. So unfortunately,
both of those always go to the sewer. Next up,
for the shower how close do you trench to your trees?
So in a typical situation, you might have more mature trees than I do.
And you would trench it roughly to the drip line. The drip line of a tree,
if we pretend my giant loofa here is a tree, wow,
it's like curling around me right away.
So let's say this is the canopy of the tree. Where the canopy ends,
that whole circumference, that's the drip line of the tree. So you would,
let's say the trunk's here and the drip line extends to here,
you maybe would get another six to 12 inches out and then you'd trench that area
right there.
Because the tree's feeder roots are probably coming out roughly to that drip
line area.
So you don't want to damage them by trenching straight through that root
structure. Really common question here,
is there a micro-plastic buildup from the washing machine? Yeah, there is,
unfortunately that is just the truth of wearing any sort of non-natural fabric.
You're going to have microplastics that are being thrown off in the wash.
So what you'll notice is my system, I don't have a microplastic filter.
That's actually something I'm heavily considering getting here at the Homestead.
I don't have it. I didn't have the time to install it.
We didn't have the expertise on hand to do it at that moment in time.
It might be something I retrofit with but, I'll be honest with you guys,
at the level that I'm operating out here I just don't think it's a huge deal to
have a little bit of that get into my soil. I don't think it's that big.
We're talking on the very, very, very low, low,
low parts per millions or tens of millions relative to what's actually in the
water. I don't think it's a massive deal at all in my case. The next one up,
how would this change if you were in an area where it actually froze in the
winter? I don't know. I mean, I live in San Diego.
It's never frozen here in my entire life.
What I would imagine is that maybe some of the materials and seals might change
and then maybe the depth at which you're burying all the lines that go out
either to your, you know,
your orchard or your patch would probably go quite a bit deeper.
So the trenching effort would probably be a little bit more,
but I would have to defer to someone in a cold zone on that one unfortunately.
The final question is the most important one probably if you have a greywater
system.
What do you actually have to do to maintain it over the course of the seasons
and years? It's actually really easy, guys.
All you have to do is check the system in a sort of systematic way.
So what I would do is I would turn my shower on,
I'd make sure it was going out to the greywater.
I'd make sure that I have dug my trenches out slightly so I could at least
access the irrigation control valve area that's covered up.
And I'd pop the tops off.
I'd make sure that water was flowing out of both and it was flowing in a
relatively consistent way.
And then what I would do is I'd make sure that it was actually draining within a
reasonable amount of time from the time that it came out. If the flow was off,
like one side was getting more than the other,
I might check the level of the pipe that was going out to the system.
I might mess around with a valve outlet and let a little bit more water out or a
little bit less water out in one of those areas. But that's pretty much it.
All you need to do is just check for any issues. And if it's not draining,
there's only a couple of reasons why it wouldn't be doing so.
So you just fix those problems. So that is it.
That's as many questions as I could possibly get for you guys on greywater
systems. If you have any more,
maybe I'll do an update video later on down the line on a maintenance or
something like that. So drop them in the Comments, but hopefully it was helpful.
I really think greywater is going to be one of the sort of obvious,
no duh standard things that'll be going into future homes no matter where they
are. It just seems to make a lot of sense.
If you think about the level of sewer treatment overload that
we aren't doing anymore if I'm diverting my entire shower,
my entire laundry - huge sources of water output to the sewer system.
If every household did that we'd actually cut the sewage treatment burden by
about 50ish percent or so.
So you think about these individual actions in a single home,
then scaled out and stamped out to every single home in America,
around the world. Eventually we can hope, right? It's actually pretty powerful.
What we could actually do to relieve.
Some of the stresses we have on this modern architecture, this modern society.
So I think it's really important. And I think that if you're considering it,
pull the trigger on it.
It's one of my favorite things that I've done here on the Homestead.
So hopefully it was helpful. Good luck in the garden and keep on growing.