"It can't touch the ground." Options?

Hi Feidhlim!

Some friends of mine are building an off-grid house for 4 residents plus occasional visitors. They will use a dry composting toilet, but would like all other water to be reused. The regulators in their area are better than most, but very concerned about protecting all the shallow water wells that are common there. The way I heard it, the regulators said, "You can do anything you want, but no effluent of any kind can ever touch the ground." My friends have some ideas about troughs full of plants, I think, but I don't know the details. This is Texas where it is hot and dry for nine months a year.

I thought it would be fun to brainstorm here about what could be done for a system with such a constraint. Anyone ever heard of such a thing?

Kerry Rodgers wrote:
"You can do anything you want, but no effluent of any kind can ever touch the ground."

Seems to me the key word here is "effluent". At what point does this become just plain water? I would get a very specific definition before going further, then work on converting the gray water (effluent) to good quality water for plants and other uses (something that could pass a water quality test). Could be that using a covered settling tank to start - with an overflow into an open, plant-filled "scrubbing pond" - followed by an overflow into an even cleaner wildlife pond, etc. might work. Technically it could touch the ground if it came out as clean water at the end of that system. Plants like cattails, water hyacinths, etc. do a fantastic job of filtering out all the icky stuff and making nice, clean water - especially if you run the overflow water across a sloping pebble and sand "stream bed" to aerate it between pools. It could look beautiful in the process.

New York State is extremely strict about this - there is no such thing as gray water. Any water that has touched your hands (possibly even your laundry) is sewage and must be treated as such. And my local inspectors are very friendly and accommodating, but they cannot bend on this. A treatment system such as described might be allowable if it was totally shielded from potential leakage to groundwater or overflow until the ehd of the last step.

Ridiculous I know, but that is the law now.

Since it is hot and dry, why not look into something like an evapocycle? We run a similar operation where I am and one in Samoa as well. It is fed off a biogas reclamation system and the effluent just evaporates, never touching the ground.

Deb Stephens wrote:
Seems to me the key word here is "effluent". At what point does this become just plain water?

I was paraphrasing here. It seems like my friends think they have to evaporate the water, because it would never become just plain water, no matter what they did to it. BTW, this county has no problem with the composting toilet, which others around here don't allow.

Glenn : I expect that if you actually have to get a certificate of Occupancy in your location of new york state, ( as opposed to a non permanent dwelling like a Tent-Yurt),
you are stuck with what ever you are told to do. I am happy with my exemption!

In the Last 40 years as the price of agricultural land has spiked in Ohio and Pennsylvania the Amish have flocked into our corner (Jefferson and St. lawrence Counties)
and have privies and dry wells ! -The Amish do end up in court every 5-10 years or so, but generally it is building code issues not plumbing !

For the Good of the Craft ! Big AL

With some glass panes over a holding tank or trough, you could try and capture the distillate as it evaporates naturally.

I got a proper permit for my house septic system & leachfield (back when the county would take the results of your test pits and design a system for you), but I'm not telling anybody what I will do with my household graywater. I host an annual festival with several hundred campers for three days, so the inspectors have to get involved in that. Fortunately, they let me run the short-term graywater effluent (showers, kitchen) into my septic tank. We rent lots of portajohns to avoid sewage handling.

I like the "distilling" notion... What evaporates and condenses on the glass should reasonably be considered not part of your effluent, since it is not directly connected even by aerosol if you have still air, and draining the glass condensate off the edge seems prudent. How much use that would be depends on your climate and your flow.

Hi Kerry,

Your friends' predicament sounds very like a lot of queries that I get here in Ireland as well. In order to build a zero discharge willow facility in Ireland you'd need about 6m x 40m of a fully plastic-lined basin, 1.5m deep. This is backfilled with soil and a spreading pipe and pump-fed with effluent from the septic tank. This is based on a Danish design that has worked well there for the last 20 years, but is very new here in Ireland. Essentially, all effluent (grey water and black water) is either stored or evaporated.

In Texas the evapotranspiration rates would clearly be much higher, so the land area required would be a lot smaller. My Danish design partner for willow facilities, Peder Gregersen, uses bamboo for evapotranspiration systems in Africa. Willows won't grow without frosts, but the bamboo works fine there. I'm not sure what your winters are like - do willows thrive in Texas or would you need something else?

In short - yes a system can be designed to contain or evapotranspire 100% of the effluent - whether grey water only, or grey and black combined. What size is their site?

Oh, and Deb's point about effluent. Certainly in Ireland, once it's left the house from a grey water source or the loo - it's effluent. Not matter how clean you get it, it's still classed as domestic wastewater. It can get a bit frustrating to offer constructed wetlands and reed bed systems that can get the water cleaner than the local river and not be allowed to discharge it there - but as Glenn says, the law's the law.

Sounds like it should be kept indoors in order to deal with the law.
I have been working on a vermicomposting grey water filter like the one Abe Connolly of Velacreations uses.
I want to direct my greywater to my conventional flush toilets,as a cold weather use. To avoid stored greywater becoming blackwater I would want to filter it. I am considering a solar powered pump to continuously filter the stored water.
Ultimately I am not sure if messing with greywater recyling is worth it for me, given my situation.
A shallow above ground pool/tank could be planted with cat tails or have floating rafts of other plants on it.
Making it long and narrow would fit better in a hoop house or high tunnel,to promote evaporation.

Feidhlim Harty wrote:I'm not sure what your winters are like - do willows thrive in Texas or would you need something else?

Once they're established (and I mean if they make it to 5-6 ft tall when started from a 2 ft cutting) willows in very wet areas will do extremely well.

At a previous house, the washing machine discharged into the yard, making a swampy spot that liked to trap the lawnmower. I planted a willow cutting there, and within a year it was 7 feet tall and gave me a perfect excuse not to mow that spot.

Growing up, we always had a couple of willows on the septic tank overflow. Here at the office, there's sort of a swampy bit nearby on a drainage ditch that doesn't flow most of the year, and it's lined with them naturally.

Hi Joe, for Irish conditions the usual size is about 6m x 40m x 1.5m deep for a willow facility for zero discharge out of it. In Texas you'd have a much lower rainfall rate ranging from <14" (355mm) to >54" (1371), compared to our <800mm to >2800mm. Thus your willow facilities in the drier parts of Texas could feasibly be about half the size, as long as the storage in the soil is sufficient to hold the water. Just a note of warning, usually willow systems aren't used in areas wetter than about 1000mm of annual rainfall here.

Hope that helps.