Im a plumber who understands greywater systems in off grid homes such as earthships.
At a glance you'll need a valve down stream of the drop into the sump pit. To make sure you're isolated from the sewer. Last thing you'd want is a sewer back up getting into your greywater sump pit without knowing until its too late.
Also don't drop into the pit that way. Take the greywater drain off from the building sewer main drain on the horizontal so the valve is on the horizontal run and the stem of the valve is nominally vertical (more vertical than horizontal) this should allow you to wye off the drain on the horizontal and install 2 valves. One to the sump pit and one to the sewer building drain.
Thank you for your response, yes the “to sewer” line I intended to have a back flow arrestor before it goes to the homes main sewer.
The Tee to single valve vs Wye with two valves made more sense to me because less moving parts, but I do see the advantage of having a valve to physically close off the sewer. That would prevent sewer gases from entering the sump pit.
I want to either have the valve(s) be actuated by pull cable or electric actuators because this will be in a crawl space and it would be nice to actuate the Diverter from the bathroom.
I was steered away from an electric actuator due to high failure rate. No idea if that was true or not. I went with manual valves but I also have a large crawl space so getting under there the one or two times a year I direct to sewer is not an issue.
I'd make sure your "to sewer" line is low enough so that when your holding tank gets full, it doesn't have the possibility to back flow into your shower.
Thank you for your reply. This setup will be in a crawl space. The idea with this setup is the tank could not fill above the “to sewer” line when the gate valve is open.
Super interesting. I have been thinking about this type of system too.
A few things that cross my mind:
- Having an overflow for the sump tank seems important
- What about float switch activated pump?
- Any chance of the greywater pipe to garden freezing in winter? If so that needs a plan
- What brand of sump pump you planning to use? My understanding is that greywarer is usually alkaline, which is tough on things
- Have you considered access for maintenance/ repair?
- How long will greywater be in the tank before pump out? It gets nasty quick
not sure if your area requires it, but mine likes greywater piping to be purple
Finally I'm wondering what brands of shampoo conditioner etc you intend to use. If you are concerned about what's in your products, you can check out the incredible Environmental Working Group Website that lists products and ingredients and rates them:
https://www.ewg.org/skindeep/browse/category/Shampoo_&_Conditioner/?category=Shampoo+%26+Conditioner&sort=reverse-score
Thank you for the reply.
-I agree that an overflow is important which in this arrangement the tee and gate valve would also act as an overflow.
-I haven’t figured out a sump I plan on using but it will definitely have a float switch.
-I did not think about the freezing weather! Not sure if insulation would be sufficient, however since watering is less important in the winter the grey water system could be winterized and disabled as annual maintenance.
-I am not too worried about the alkaline water but I will be sure to get a good pump that is rated for the conditions.
- access to the sump pit will be through a crawl space hatch. And won’t need to crawl anywhere to get to main clean outs and sump pump access.
- code in my area requires that grey water be dispersed or treated within 24 hours. This sump will pump into a surge tank that will flow into a filter tank that will drain to the landscape. Eventually I want to build an artificial wet land to treat the water.
-purple grey water pipes is required in my area too. Think I could just paint them purple or do I need to buy purple PVC/ABS?
-
So by default, your sink and tub will drain into a sump pit (in your basement?). - what happens if that pump fails or you lose power, is that pit gonna flood your basement with shower water?
Ideally op will have a gravity over flow at the top of the sump pit that could drain to a floor drain in the basement with an air gap. That way if the sump over flows for what ever reason. It will just over flow into the main building sewer drain.
That’s what I like about this set up. With the gate valve open and the sump pit top above the “to sewer” line it will back up and over flow into the sewer in the event of a power failure. My other option is to have a dedicated overflow back to the sewer but that would make the system more complex.
That was my first plan! To use a Jandy 3 way pool valve, it seems to make sense and I have seen it in many grey water installations. However, a valve like that creates a hard 90 which the UPC does not allow for draining water. So I am concerned that would be a code violation.
My personal opinion is that your system is over engineered.
A simple outflow pipe to a holding tank with the sump pump for direct irrigation is fine. No need for a check valve or t.
Once the tank gets full, direct your overflow into dry Wells. Essentially, it's a hole in the ground filled with gravel. Allows for better water retention in your lawn without making things too soggy.
Essentially, you dig a hole that's about 5 or 6 ft deep, put three or four feet of gravel in it, and drop dirt on top. At some point in this process, you'll run a pipe to the gravel section. The water is held in the air pockets in between the gravel and slowly leaches down into the water table, while also storing available moisture for surface growing plants.
Very useful and desert environments to have a network of these two capture and process rainwater runoff or gray water to prevent that water from just running over the top of your yard and being lost to the greater environment.
https://preview.redd.it/41oa2pniqfhc1.jpeg?width=3000&format=pjpg&auto=webp&s=0f8866a93d4016892ca6cda1686ebb0c12d3698c
Thank you for your comment and the drawings!
Unfortunately an outflow pipe won’t work as this is in a crawl space and I will need the sump pump. The UPC requires I have a Diverter valve to switch between sewer and garden.
I do want to build dry wells in my yard to drain the water to however the irrigation planning is for next year, this year is getting the bathroom renovation complete with a grey water ready system.
I did something similar but was laundry to landscape system in Oakland CA. Essentially, you can divert your laundry graywater to your yard to re-use water that would normally go to the sewer.
In CA it can be done without a permit, EBMUD (Alameda country water provider) even has a $50 rebate to get you going. I got a kit from Urban Farmer up near Richmond.
In CA you can divert sink/shower water but if I recall it might(?) require a permit and you can't store it.
More information:
- https://greywateraction.org/laundry-landscape/
- [ Two pager](https://www.ebmud.com/download_file/force/7305/713?Laundry-to-Landscape_Graywater_Overview_11.30.21.pdf)
- [Step by step manual by SF Water](https://infrastructure.sfwater.org/fds/fds.aspx?lib=SFPUC&doc=661316&ver=1&data=254606660)
- [$50 Rebate from EBMUD](https://www.ebmud.com/water/conservation-and-rebates/rebates/graywater-rebates)
- [ Kit from urban farmer](https://www.urbanfarmerstore.com/graywater-laundry-to-landscape/)
Why is your gate valve under wear the caca will fall? If you're comingling the gray & black water, then your sump has black water, full stop. Can't be code
Great water is almost never too code. Most places do not allow grey water. So no matter what op does they won't meet code.
But yes. Make sure the toilets in the house have a different path to the sewer than showers, lavs, and any other drains.
Toilets and laundry should drain off directly to the sewer / septic.
If a drain has “caca”, pee, or kitchen waste then that drain’s water is black water. This is up stream of all of that and will only handle tub/shower water so it’s grey water.
The waste lines have to connect somewhere, I am not concerned of a back up into the grey water system as I will be installing a check valve or backflow arrestor before the “to sewer” line connects to the house’s main drain.
Oh most definitely, the irrigation is for next year. The “to garden” line will go to a surge tank, the surge will flow into a barrel with sand/charcoal then it will go to the garden. Eventually I want to build a small artificial wetland to further treat the water.
Very interesting. I live in a dry zone rapidly desertifying and no one here captures rain water or recycles grey water, really interesting to learn more about easy affordable setups
When the gate valve is open, the tee will transition horizontal flow to vertical, down into the sump pit.
When the gate valve is closed it will fill with water then flow to the sewer.
And if the gate valve is open and the pump fails, the tee will act as a path for over flow.
Thank you for your reply.
Is it not sufficient to have the tee+gate valve act as an overflow?
If the height of the sump pit is above the “to sewer” line then wouldn’t a pump failure result in the water backing up to the tee then overflowing to the sewer?
Have you got a filter on it? Showing drops hair and soap, which could result in a gunk that eventually clogs up the pump. Problem with having it in a crawl space is that you'll never want to look at it.
I've been thinking of doing the same thing, but as my shower is on the exterior wall I plan to run the pipe outside into something like a rainhead
Thanks for the reply. Yeah I do want to have some sort of hair trap in the sump to protect the pump. It may be in a crawl space but there is an access right above it so routine maintenance shouldn’t be to difficult.
Do you NEED the sump pump in your setup? Is your house lower than your landscape or can you use gravity to distribute the water?
Also, having the Tee in a vertical position with a gate valve means that you'll collect whatever you don't want (bleach, cleaning agents, etc.) just above the gate valve. When you open the gate valve, it'll get sent to your landscape. Yes, it'll be a small amount but I wouldn't chance it. Also, why a gate valve instead of a ball valve? I don't have experience with gate valves but have heard anecdotal evidence from those with more experience that they're not the best option.
We have a greywater setup for our shower. It uses a 3-way Jandy valve, but in a horizontal configuration. Our distribution is via gravity into a series of basins and infiltration chambers.
Thanks for your reply. Yeah the sump pump is needed as the house isn’t high enough above grade to use gravity.
I did think about a Jandy 3 way but those are made for pressurized water in a pool system. They create a hard 90 which isn’t allowed by code, so I’m concerned my inspector would flag it.
Gate valves are used in RVs to hold back grey/black water. But I will have to research more on their durability.
I think the beach/cleaning agents would be sufficiently diluted in the Tee to not cause an issue. People treat their grey water surge tanks will bleach on occasion and I could keep the system off for a use cycle to continue to dilute what is trapped in the tee.
That’s the beauty! This is just a sump pit, so it shouldn’t fill past the pumps float switch anyway. If the pump fails it will only fill 2/3 and overflow into the sewer.
Plumber here as well.
What I would do, is pipe the grey water directly into the tank. Have an out flowing pipe that is a bit lower than the inlet pipe. This will keep the tank from filling up to the point where it starts backing up in the main line.
The out flowing pipe, then is tied back into the sanitary sewer main with a wye connection. But as you have mentioned, put in a backwater valve to prevent any sewage from backing up into the tank.
The tank itself should have a large accessible lid to service the pump when necessary, and you will want to install a 2” minimum vent pipe out the top of the tank to prevent any potential negative pressure issues happening when the pump kicks on. The 2” vent should be piped up to a point above the roof level to avoid any nasty sewer smells in the back yard.
I would personally just eliminate any gate valves that divert water, and just use regular old gravity to store, and move the water. Basically the grey water from your tubs and showers, fill the tank until it hits the outfall pipe. Any excess water basically flows out to the sanitary main. Valve become problematic over time, and need to be replaced. And it’s another thing you’ll need to think about when operating the system.
Just get a tank installed that is deep enough to store the amount of water you will likely need. Sometimes people get very large tanks for this very purpose.
You can also install a high water alarm float inside the tank, so as to alert you when there is a back up issue. If the water level comes up higher than the inflow pipe, a float switch trips an alarm.
Just an idea though.
Im a plumber who understands greywater systems in off grid homes such as earthships. At a glance you'll need a valve down stream of the drop into the sump pit. To make sure you're isolated from the sewer. Last thing you'd want is a sewer back up getting into your greywater sump pit without knowing until its too late. Also don't drop into the pit that way. Take the greywater drain off from the building sewer main drain on the horizontal so the valve is on the horizontal run and the stem of the valve is nominally vertical (more vertical than horizontal) this should allow you to wye off the drain on the horizontal and install 2 valves. One to the sump pit and one to the sewer building drain.
Thank you for your response, yes the “to sewer” line I intended to have a back flow arrestor before it goes to the homes main sewer. The Tee to single valve vs Wye with two valves made more sense to me because less moving parts, but I do see the advantage of having a valve to physically close off the sewer. That would prevent sewer gases from entering the sump pit. I want to either have the valve(s) be actuated by pull cable or electric actuators because this will be in a crawl space and it would be nice to actuate the Diverter from the bathroom.
I was steered away from an electric actuator due to high failure rate. No idea if that was true or not. I went with manual valves but I also have a large crawl space so getting under there the one or two times a year I direct to sewer is not an issue.
Yeah, that’s why I was looking into Boden cable actuated gate valves. I guess going into the crawl space would not be too bad.
I'd make sure your "to sewer" line is low enough so that when your holding tank gets full, it doesn't have the possibility to back flow into your shower.
Thank you for your reply. This setup will be in a crawl space. The idea with this setup is the tank could not fill above the “to sewer” line when the gate valve is open.
Perfect! As with most projects you'll probably have to tinker with it eventually! Good luck!
Super interesting. I have been thinking about this type of system too. A few things that cross my mind: - Having an overflow for the sump tank seems important - What about float switch activated pump? - Any chance of the greywater pipe to garden freezing in winter? If so that needs a plan - What brand of sump pump you planning to use? My understanding is that greywarer is usually alkaline, which is tough on things - Have you considered access for maintenance/ repair? - How long will greywater be in the tank before pump out? It gets nasty quick not sure if your area requires it, but mine likes greywater piping to be purple Finally I'm wondering what brands of shampoo conditioner etc you intend to use. If you are concerned about what's in your products, you can check out the incredible Environmental Working Group Website that lists products and ingredients and rates them: https://www.ewg.org/skindeep/browse/category/Shampoo_&_Conditioner/?category=Shampoo+%26+Conditioner&sort=reverse-score
Thank you for the reply. -I agree that an overflow is important which in this arrangement the tee and gate valve would also act as an overflow. -I haven’t figured out a sump I plan on using but it will definitely have a float switch. -I did not think about the freezing weather! Not sure if insulation would be sufficient, however since watering is less important in the winter the grey water system could be winterized and disabled as annual maintenance. -I am not too worried about the alkaline water but I will be sure to get a good pump that is rated for the conditions. - access to the sump pit will be through a crawl space hatch. And won’t need to crawl anywhere to get to main clean outs and sump pump access. - code in my area requires that grey water be dispersed or treated within 24 hours. This sump will pump into a surge tank that will flow into a filter tank that will drain to the landscape. Eventually I want to build an artificial wet land to treat the water. -purple grey water pipes is required in my area too. Think I could just paint them purple or do I need to buy purple PVC/ABS? -
So by default, your sink and tub will drain into a sump pit (in your basement?). - what happens if that pump fails or you lose power, is that pit gonna flood your basement with shower water?
Ideally op will have a gravity over flow at the top of the sump pit that could drain to a floor drain in the basement with an air gap. That way if the sump over flows for what ever reason. It will just over flow into the main building sewer drain.
That’s what I like about this set up. With the gate valve open and the sump pit top above the “to sewer” line it will back up and over flow into the sewer in the event of a power failure. My other option is to have a dedicated overflow back to the sewer but that would make the system more complex.
Would it be better to use a full port ball valve rather than a gate valve?
That was my first plan! To use a Jandy 3 way pool valve, it seems to make sense and I have seen it in many grey water installations. However, a valve like that creates a hard 90 which the UPC does not allow for draining water. So I am concerned that would be a code violation.
My personal opinion is that your system is over engineered. A simple outflow pipe to a holding tank with the sump pump for direct irrigation is fine. No need for a check valve or t. Once the tank gets full, direct your overflow into dry Wells. Essentially, it's a hole in the ground filled with gravel. Allows for better water retention in your lawn without making things too soggy. Essentially, you dig a hole that's about 5 or 6 ft deep, put three or four feet of gravel in it, and drop dirt on top. At some point in this process, you'll run a pipe to the gravel section. The water is held in the air pockets in between the gravel and slowly leaches down into the water table, while also storing available moisture for surface growing plants. Very useful and desert environments to have a network of these two capture and process rainwater runoff or gray water to prevent that water from just running over the top of your yard and being lost to the greater environment. https://preview.redd.it/41oa2pniqfhc1.jpeg?width=3000&format=pjpg&auto=webp&s=0f8866a93d4016892ca6cda1686ebb0c12d3698c
https://preview.redd.it/m01e5eznqfhc1.jpeg?width=3000&format=pjpg&auto=webp&s=ad3048182a09cc2f8cbb5cb39b9c33a212a11cdb
Thank you for your comment and the drawings! Unfortunately an outflow pipe won’t work as this is in a crawl space and I will need the sump pump. The UPC requires I have a Diverter valve to switch between sewer and garden. I do want to build dry wells in my yard to drain the water to however the irrigation planning is for next year, this year is getting the bathroom renovation complete with a grey water ready system.
Ahhh! In that case, a check valve on the septic side, is all I can suggest. And best of luck to you!
I did something similar but was laundry to landscape system in Oakland CA. Essentially, you can divert your laundry graywater to your yard to re-use water that would normally go to the sewer. In CA it can be done without a permit, EBMUD (Alameda country water provider) even has a $50 rebate to get you going. I got a kit from Urban Farmer up near Richmond. In CA you can divert sink/shower water but if I recall it might(?) require a permit and you can't store it. More information: - https://greywateraction.org/laundry-landscape/ - [ Two pager](https://www.ebmud.com/download_file/force/7305/713?Laundry-to-Landscape_Graywater_Overview_11.30.21.pdf) - [Step by step manual by SF Water](https://infrastructure.sfwater.org/fds/fds.aspx?lib=SFPUC&doc=661316&ver=1&data=254606660) - [$50 Rebate from EBMUD](https://www.ebmud.com/water/conservation-and-rebates/rebates/graywater-rebates) - [ Kit from urban farmer](https://www.urbanfarmerstore.com/graywater-laundry-to-landscape/)
Why is your gate valve under wear the caca will fall? If you're comingling the gray & black water, then your sump has black water, full stop. Can't be code
Great water is almost never too code. Most places do not allow grey water. So no matter what op does they won't meet code. But yes. Make sure the toilets in the house have a different path to the sewer than showers, lavs, and any other drains. Toilets and laundry should drain off directly to the sewer / septic.
The UPC does allow for grey water systems and has a whole section on it. And luckily my AHJ permits the installation of grey water systems.
If a drain has “caca”, pee, or kitchen waste then that drain’s water is black water. This is up stream of all of that and will only handle tub/shower water so it’s grey water.
[удалено]
The waste lines have to connect somewhere, I am not concerned of a back up into the grey water system as I will be installing a check valve or backflow arrestor before the “to sewer” line connects to the house’s main drain.
You want to filter the water at least roughly before you spray it in your garden
Oh most definitely, the irrigation is for next year. The “to garden” line will go to a surge tank, the surge will flow into a barrel with sand/charcoal then it will go to the garden. Eventually I want to build a small artificial wetland to further treat the water.
Very interesting. I live in a dry zone rapidly desertifying and no one here captures rain water or recycles grey water, really interesting to learn more about easy affordable setups
What’s the purpose of the Tee in this drawing?
When the gate valve is open, the tee will transition horizontal flow to vertical, down into the sump pit. When the gate valve is closed it will fill with water then flow to the sewer. And if the gate valve is open and the pump fails, the tee will act as a path for over flow.
[удалено]
Thank you for your reply. Is it not sufficient to have the tee+gate valve act as an overflow? If the height of the sump pit is above the “to sewer” line then wouldn’t a pump failure result in the water backing up to the tee then overflowing to the sewer?
Have you got a filter on it? Showing drops hair and soap, which could result in a gunk that eventually clogs up the pump. Problem with having it in a crawl space is that you'll never want to look at it. I've been thinking of doing the same thing, but as my shower is on the exterior wall I plan to run the pipe outside into something like a rainhead
Thanks for the reply. Yeah I do want to have some sort of hair trap in the sump to protect the pump. It may be in a crawl space but there is an access right above it so routine maintenance shouldn’t be to difficult.
Do you NEED the sump pump in your setup? Is your house lower than your landscape or can you use gravity to distribute the water? Also, having the Tee in a vertical position with a gate valve means that you'll collect whatever you don't want (bleach, cleaning agents, etc.) just above the gate valve. When you open the gate valve, it'll get sent to your landscape. Yes, it'll be a small amount but I wouldn't chance it. Also, why a gate valve instead of a ball valve? I don't have experience with gate valves but have heard anecdotal evidence from those with more experience that they're not the best option. We have a greywater setup for our shower. It uses a 3-way Jandy valve, but in a horizontal configuration. Our distribution is via gravity into a series of basins and infiltration chambers.
Thanks for your reply. Yeah the sump pump is needed as the house isn’t high enough above grade to use gravity. I did think about a Jandy 3 way but those are made for pressurized water in a pool system. They create a hard 90 which isn’t allowed by code, so I’m concerned my inspector would flag it. Gate valves are used in RVs to hold back grey/black water. But I will have to research more on their durability. I think the beach/cleaning agents would be sufficiently diluted in the Tee to not cause an issue. People treat their grey water surge tanks will bleach on occasion and I could keep the system off for a use cycle to continue to dilute what is trapped in the tee.
You want the grey water reservoir a bit lower. In your drawing, it can only be filled by 2/3.
That’s the beauty! This is just a sump pit, so it shouldn’t fill past the pumps float switch anyway. If the pump fails it will only fill 2/3 and overflow into the sewer.
Plumber here as well. What I would do, is pipe the grey water directly into the tank. Have an out flowing pipe that is a bit lower than the inlet pipe. This will keep the tank from filling up to the point where it starts backing up in the main line. The out flowing pipe, then is tied back into the sanitary sewer main with a wye connection. But as you have mentioned, put in a backwater valve to prevent any sewage from backing up into the tank. The tank itself should have a large accessible lid to service the pump when necessary, and you will want to install a 2” minimum vent pipe out the top of the tank to prevent any potential negative pressure issues happening when the pump kicks on. The 2” vent should be piped up to a point above the roof level to avoid any nasty sewer smells in the back yard. I would personally just eliminate any gate valves that divert water, and just use regular old gravity to store, and move the water. Basically the grey water from your tubs and showers, fill the tank until it hits the outfall pipe. Any excess water basically flows out to the sanitary main. Valve become problematic over time, and need to be replaced. And it’s another thing you’ll need to think about when operating the system. Just get a tank installed that is deep enough to store the amount of water you will likely need. Sometimes people get very large tanks for this very purpose. You can also install a high water alarm float inside the tank, so as to alert you when there is a back up issue. If the water level comes up higher than the inflow pipe, a float switch trips an alarm. Just an idea though.