For a long while I've wanted to be able to water our backyard ornamental garden with gray water. We already have a drip irrigation system and, while those are known for using water very efficiently, it still uses quite a lot of water. I researched gray water systems online and in books, but I didn't find any that would work similarly to a drip irrigation system by delivering the water to a large number of plants individually (actually, there are such systems, but they must be professionally installed and cost thousands of dollars).
Typical gray water garden systems deliver water to a few fruit trees or to large areas called "mulch basins" or they have water coming out of a hose that one can move around manually to different plants. What I wanted was a system that would take my gray water and distribute it to all of the places where the drip irrigation system goes. After almost six months of pondering this problem, last summer (2009), I hit upon a very simple solution that appears to work very well. I used it for a couple of months before our rainy season came, and then I switched the washing machine over to another water saving device, my laundry water recycler. Now the rainy season is coming to an end here in N. California, so I'll be reconnecting the irrigation system soon. Read on and you'll see how it works. I look forward to your comments and suggestions.
Typical gray water garden systems deliver water to a few fruit trees or to large areas called "mulch basins" or they have water coming out of a hose that one can move around manually to different plants. What I wanted was a system that would take my gray water and distribute it to all of the places where the drip irrigation system goes. After almost six months of pondering this problem, last summer (2009), I hit upon a very simple solution that appears to work very well. I used it for a couple of months before our rainy season came, and then I switched the washing machine over to another water saving device, my laundry water recycler. Now the rainy season is coming to an end here in N. California, so I'll be reconnecting the irrigation system soon. Read on and you'll see how it works. I look forward to your comments and suggestions.
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Signing UpStep 1: Description of the Watering Technique
Although it took me six months to figure this out, the technique is extremely simple. First, I decided not to use any water from the kitchen for this gray water system, because of the difficulty of filtering out food particles. This system exclusively uses water from our clothes washing machine, which does contain a lot of lint, but that is easy to filter out. NOTE THAT, FOR HEALTH REASONS, IT IS NOT RECOMMENDED TO WATER VEGETABLES WITH GRAY WATER (fruit trees are OK though).
Drip irrigation systems water individual plants with little parts called "emitters" that allow the water to drip out. They are specially designed to not clog with roots or debris, but they require a fair amount of water pressure to operate and everything I have read about gray water systems warns that emitters will become clogged if you try and put gray water through them. However, there is another part, frequently used in drip irrigation systems that is the key to my system. It's called a 'barb x barb" connector and you can see a picture of one here (I'm not trying to endorse this vendor, it's just the first photo I found on the web). The barb x barb is made to connect a 1/4" diameter extension hose to a larger main line. In my system, I just put one of these barb x barbs next to each plant that will be watered. The first photo below shows one of these "barb emitters" in action.
Each barb x barb has a hole that's maybe 1/16" in diameter, and this is large enough so that it won't clog (at least they haven't clogged after the first few months of use last summer and fall). In my first version of the system, I put the barb emitters at a slight upward angle, like in the photo. There were two problems with this: First, in some parts of the terrain, the pressure became low enough so that having the barbed emitter pointing up led to low or no water flow. Also, one of the nicest things about drip irrigation systems is that it delivers the water underground, so you get less evaporation. Putting the barb emitters straight down, sticking into the soil, would help the gravity/pressure problem and also the evaporation problem. However, just sticking the barb emitter into the soil could lead to clogging with particles or roots.
So, my second version goes as follows (see photos 2-5 below): I insert the barb x barb into the hose pointing straight down, then I wrap the middle section of the barb x barb with adhesive foam weather stripping. I then use a wooden dowel to poke a hole in the soil just under the barb emitter. I take a 3" length of irrigation tubing, fit it snugly over the weather stripping, and insert the tube into the hole in the ground. That way, the barb emitter has an empty space below it that is kept open by the tubing. I have had some of these in place since last fall and soon I'll check them to see if they are still working. Overall, I think the second version is a better idea, but there's something really gratifying about seeing the water squirting out of the above-ground barb emitters.
***UPDATE - the weatherstripping didn't hold up very well over the winter, so I'll need to find another way to plug up the hole. For now, I'm just leaving them unplugged ***
Sometimes I don't have the main irrigation tube very near a plant. In those cases, I just insert a barb emitter nearby, and then insert a piece of 1/4' tubing to bring the water flow right to the plant (which is what barb x barbs are meant to do).
Drip irrigation systems water individual plants with little parts called "emitters" that allow the water to drip out. They are specially designed to not clog with roots or debris, but they require a fair amount of water pressure to operate and everything I have read about gray water systems warns that emitters will become clogged if you try and put gray water through them. However, there is another part, frequently used in drip irrigation systems that is the key to my system. It's called a 'barb x barb" connector and you can see a picture of one here (I'm not trying to endorse this vendor, it's just the first photo I found on the web). The barb x barb is made to connect a 1/4" diameter extension hose to a larger main line. In my system, I just put one of these barb x barbs next to each plant that will be watered. The first photo below shows one of these "barb emitters" in action.
Each barb x barb has a hole that's maybe 1/16" in diameter, and this is large enough so that it won't clog (at least they haven't clogged after the first few months of use last summer and fall). In my first version of the system, I put the barb emitters at a slight upward angle, like in the photo. There were two problems with this: First, in some parts of the terrain, the pressure became low enough so that having the barbed emitter pointing up led to low or no water flow. Also, one of the nicest things about drip irrigation systems is that it delivers the water underground, so you get less evaporation. Putting the barb emitters straight down, sticking into the soil, would help the gravity/pressure problem and also the evaporation problem. However, just sticking the barb emitter into the soil could lead to clogging with particles or roots.
So, my second version goes as follows (see photos 2-5 below): I insert the barb x barb into the hose pointing straight down, then I wrap the middle section of the barb x barb with adhesive foam weather stripping. I then use a wooden dowel to poke a hole in the soil just under the barb emitter. I take a 3" length of irrigation tubing, fit it snugly over the weather stripping, and insert the tube into the hole in the ground. That way, the barb emitter has an empty space below it that is kept open by the tubing. I have had some of these in place since last fall and soon I'll check them to see if they are still working. Overall, I think the second version is a better idea, but there's something really gratifying about seeing the water squirting out of the above-ground barb emitters.
***UPDATE - the weatherstripping didn't hold up very well over the winter, so I'll need to find another way to plug up the hole. For now, I'm just leaving them unplugged ***
Sometimes I don't have the main irrigation tube very near a plant. In those cases, I just insert a barb emitter nearby, and then insert a piece of 1/4' tubing to bring the water flow right to the plant (which is what barb x barbs are meant to do).
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I do not care that much about foodscraps in the grey water other than that it might block my hoses. Therefore most of my grey water from the kitchen goes to a basin in which food scraps sink and it is pumped into the garden through a filter.
My bathtub empties on the lawn and the trees whenever I pull the plug.
I live in a fairly wet country though, but especially in the summer i would consider it a waste to just let it flow down the drain to the summer.
Cost is part of the equation as water is cheap here. Most of my bill is because of taxes and levy's so I cannot make my solutions to be expensive. To give an example: By using my water wisely, I have been able to cut down from 60 m3/year to 30 m3/yr and now 15 m3/year. However, every m3 saved, saves me about 1 euro on my water bill.
If I were to buy a rainwaterbarrell to collect rainwater, that would set me back about 200 euro's (yes, expensive) for say a 150 liter barrel. I would need to save 200 m3 water to even break even, which would be 1333 full barrels. That is just not worth it.
Using graywater with relatively cheap hoses and a 15 euro pump is therefore more rewarding. For storage I use some 5 euro cement buckets that can contain I think 100 liters. I have seen some 1000 liter vessels that apparently are used to store foodstuffs and those come at 10 euro, at the local ebay but these just take up too much space. Yet, I think about buying one and just digging it in.
Thanks for sharing how to do it if you are not as lucky as we are and need pumps to lift water up and out of the house! Ours was also just trial & error, and seeing what worked and expanding it where we could! Hope you get others on board!
We heard of some of it through a book about using gray water called "Damn Nation' also a good source for building gray water systems.
Here is an explanation on chlorine bleach: http://www.howstuffworks.com/question189.htm
And here is an explanation on the rinse cycle neutralization of chlorine bleach: http://www.clorox.com/blogs/dr-laundry/2011/10/17/neutralizing-rinse/
Chlorine is in our water. We drink it. And water plants with it. A chlorine bleach cycle will probably be safer than detergents, which can be more harmful due to its chemistry of bonding to dirt/grease. I would drink a chlorine cycle glass of laundry water than a detergent cycle. Living things can tolerate everything in moderation - arsenic for instance.
Any clean watering system can even be a problem is you have it hooked into the house watering system without a backflow valve. With appropriate measures it is safe to use bath and shower water for watering if you do not use chemicalized hair and body care products and aim the water to emit gently (so it doesn't splash) and apply to the earth and not the plant itself..
Don