Anyone Have Experience with Gray Water?

[HawkinsHollow]

I have an off grid container cabin. I have a buddy living there right now, and we are trying to update systems to make it a bit less spartan. One of the systems coming online is a 330 gallon IBC with a 12v on demand pump and on demand propane hot water heater. Everyone likes a nice warm shower right? Right now he is just showering on a pallet and letting the water perc into the ground. As fall and winter approach we are going to be drying in a bathroom/shower and making it more of a permanent setup. This means we are going to have to do something with the water. This is going to be a pretty small amount of water, 1 person showering 4-5 days a week and a wash basin, no washing machine. Maybe 300-500 gallons a month. I know kitchen sinks are really not a great idea to put into gray water but I am going to add a pre strainer and make sure homie isn't putting grease down it. Also I will insist on him using biodegradable soaps. My ground does not perc great but I think it can handle this amount of water if treated well. I have designed a small treatment barrel that in my anything but expert opinion should handle the volume and produce water that is treated well enough to be let out into the environment.

Now before you ask, yes, this is an ask for forgiveness rather than permission type situation. Gray water is allowed to be used for subsurface irrigation with proper treatment in my state. The location this property is in is a rather depressed area and I am sure there are far worse things going on locally than 300 gallons of treated gray water going into the ground. And this spot is far from the prying eyes of neighbors or county officials so I feel ok about this. That being said I want to do the right thing and treat the water well in case I do get caught.

Now for the system. I have these nice 14 gallon wide mouthed barrels and the system is going to be built around that. This will be gravity fed from the bathroom and will contain 4 layers; an easily replaceable filter medium(probably drainage filter cloth), gravel, sand and finally a bioactivated mulch layer at the bottom that will eat the bad stuff. I plan on making a water distribution tee that is a 5 way 1" PVC tee with pvc section that have drill holes to distribute the water evenly over the surface of the filtering media. Here is a little schematic I drew up. This will then drain out the bottom into a leach pipe. I modelled this loosely off of the Aqua2use gray water diversion system, which is just a bunch of smaller filters (see attached picture). Hopefully with proper use this system will not need to be redone but once every couple of years. I will make it so I can easily remove the lid and replace the filter cloth every few months as I am sure it will get rather funky, I might even inoculate it with the septic bacteria as well to see if that keeps it from getting funky too quickly.

I know this seems like I am shooting from the hip on this but if you look through all of the info on gray water systems on the interwebs there are MANY different ways people deal with gray water. For my small scale system I really think this is going to work. Whatcha think?

 

[ponytug]

Wow! I think that unless your soil is straight sand or gravel, that might be overkill.

FWIW: Around here, the local regulations ask for a settling basin to catch sand, etc., and then run it out underground in plastic pipe. A few cities skip the settling basin in favor of no standing liquid to not breed anything. The consensus is for underground disposal to keep flies off of it for health reasons.

All the best,

Peter

 

[HawkinsHollow]

I honestly think just the opposite, the area I plan on putting this might perc so poorly that even with my subsurface distribution it might run out onto the surface at some point. I have a double edge sword for my situation. My soil doesn't perc the best, the direction I am draining it has a steep embankment just 20 feet downhill and a large portion of that embankment might be made up of chunky fill. The good news is that the next level down from that embankment is the only spot the soil scientist did find good percolation soil. Not ideal, but I think it will be fine if I can treat it well, thus the overkill. My hope is that it stays subsurface until it hits that fill and then percs down into that next layer. Again, this is going to be a rather low volume of water and so I think all things considered it will be ok.

 

[Larry Caldwell]

Hard no on the kitchen sink. I bought a house once with the sink not connected to the septic, and the vermin problem was horrible. Yellowjackets and rodents, mostly.

 

[HawkinsHollow]

Hard no on the kitchen sink. I bought a house once with the sink not connected to the septic, and the vermin problem was horrible. Yellowjackets and rodents, mostly.

Hmm, dually noted. Where did the kitchen sink drain into? Just out onto the surface?

 

[Larry Caldwell]

Hmm, dually noted. Where did the kitchen sink drain into? Just out onto the surface?

Yes, but the house had been vacant for months and the problem was still extreme. Don't count on occasional cabin use to help.

 

[MossRoad]

Taking a shower isn't much different than washing underwear with racing stripes. As long as the guy doesn't poop in the shower, that is.

Our washing machine goes out a 1" pipe through the basement wall, through 20ish feet of pipe, and into an upside down horse trough that's buried underground. That's the way the house came 30 years ago. There was also a previous horse trough and a 55 gallon drum. Both of those are no longer used. Our washing machine can use as much as 66 gallons on a full cycle. But we live on sand. It perks as fast as you can dump it.

I think for showers only, you're going overkill on filters, layers, etc.... and way too small on a 14 gallon container.

Take a 55 gallon drum, cut one end off, then cut it in half vertically so you have two troughs, dig a trench, fill the bottom with gravel, lay the two halves of the drum in there like arches so you now have 70" long by 23" wide surface area, or about 11 square feet. Run a 2" perforated pipe inside the length of the drum, connect to shower drain line and bury it.

If you want to test it first, build a 2' x 6' box out of 2x4, set it on the ground, dig out the inside about 3" deep, set the box in there, and dump as much water as you think a shower would use into the box. See how long it takes to go away. Repeat a few times.

 

[oldnslo]

I suspect different areas and soil types will have significantly different requirements and possibly regulations. When I bought my current home the washing machine drained straight onto the ground and the kitchen sink drained into a cistern and bathroom into normal septic system. I was told that you can still dump washing machine on top of the ground but everything else must go to septic.

Go into town or subdivision and those rules change.

 

[1 Old Man]

I suspect different areas and soil types will have significantly different requirements and possibly regulations. When I bought my current home the washing machine drained straight onto the ground and the kitchen sink drained into a cistern and bathroom into normal septic system. I was told that you can still dump washing machine on top of the ground but everything else must go to septic.

Go into town or subdivision and those rules change.

I have a friend that does similar. The shower and washing machine drain onto
the ground (and the surrounding grass, trees etc are unbelievably healthy & green).
Everything else goes to septic/leach field.

 

[jyoutz]

My house sends all of the bathroom sinks and shower water outside into a hollowed out retention basin. Then I planted cottonwood trees in the basin. There is never any standing water because the soil drains well and the trees do well with the extra water.