Playa Tested Greywater Evaporator

[capjbadger]

You're right about surface area being important.

Funny enough, the "nesting" of one loop of mesh in the other with some holes to feed it is the same design I'm working on.

[Gravity Mike]

The 'wicking' and nesting are both good ideas.

However, make sure you have good air circulation around all of the evap surfaces. I'm going to use el cheapo shade fabric for my 'wick' as it still allows a fair bit of air flow, yet is a fairly tight fabric (compared to a metal fabric).

Actually, having a fan force air up through the top plate (you'd have to make a slightly raised plenum to stop the water from falling in), thereby forcing air in through the sides (or nested sides) could help, although would increase power demand. Of course, not really necessary if there's a good cross wind.

Getting it level is important. I'm still thinking if there's a way to make this componenet easily adjustable.

Did anybody evey come up with an 'official' name for these things?

Gravity

[zimri]

I am using the screen fabric on mine as well. I also put three wooden legs on it. I am going to put a screw in the bottom of each one that will allow me to adjust the level of it more easily. with three legs instead of four, it wont wobble from just adjusting one leg. Also, depending on how thick your top plywood piece is, you may want to put some bracing supports under it so it doesnt bow.

[Hoolie]

We need a name for these things so Mr. Polando and El Subcomandante Marcos are suitably honored for freeing us from the tyrany of ineffective evaporation ponds. Suggestions?

I agree.
The "Evapolando"?
The "Aquamarc"?
The "El Sub-a-dub"?
Or simply, the "El Sub"?

[motskyroonmatick]

Victory!!!!!
I have finished my El Subcomandante Marcos evaporator. It is a clone for the most part and I am running a 500 GPH pump. If I had to do ia all over I would spring for the larger pump so that the massive flow would overcome the directed flow that the slightly warped plywood makes. Hmmm... still might get a bigger pump. Might wrap the top with felt or other porus material to create a dam and even out the flow arround the circumfrence.

Here is the picture if I can figure out how to post it.
Well no luck with the picture posting. Good at fabrication-Bad with computer stuff.

Description,
Looks just like the one in the orrigional post with 1/4 water flow and no EL wire. Pump powered by an Optima yellow top that is charged by 45 wat solar pannel and charge controller. The pump and float switch are mounted on a plastic felling wedge(the only plastic I had arround)for stability. The pump is on the low side so it will always be in water. I ran a bypass circuit arround the float switch for added operational controll.

I ran a 10 hour test and evaporated 1/2 inch of water in moderately high humidity and low wind. Temperature was max 75F. In that time span the voltage in the battery dropped from 12.59 to 12.23 volts. Recharge only brought the battery up to 12.33 in 12 hours or less charging over night in to mid morning. The 12.33 volts seems low so I may have to try a different charge controller.

I may add a 5 gallon bucket sump system to it if I can figure out an easy way to elevate the evaporator and hold it down since there will be less water weight in that scenario. The catch for the shower is a hot water heater pan that will drain into the pool or the sump.

Any thoughts?

See you soon! tick tock tick tock.

[bellboy]

i have a garden fountain pump 120vac laying around which i was thinking of using, although i tested it i'm alittle worried it might fail since it's about 20 years old. i'm in a dance camp so we'll have generators running most of the time or i can run it off my 1kw inverter in my van. i have no idea what the flow rate is, it's kinda of small, i think maybe 100 gph it puts out a good squirt at 4 feet through 5/8" line, though. i got a float switch from work and used a battery to drive a soild state relay ( also from work) the four foot pool i got has SUPRIZE a three foot bottom so i made a 3 foot circle and have a bunch of wire cloth left over. how did the idea of making multiple circles of mesh work? i think i'll get me one of those bilge pumps just in case ... never know if the playa floods i might have to pump out the van...
when will the El Subcomandante Marcos evaporator tour get to 2 oclock and fate??

[MadMaxine]

here's an idea that might solve the "water falling off one side but not the other" problem:

find an old sattelite dish and use that for the top surface (oriented like an umbrella, not a bowl). Paint it black and staple (or drill and lace with wire) the hardware cloth to the bottom edge.

Overall, it really does look like a good idea. Last year our camp handled a fair amount of grey water simply by pumping (w/filtration) into a sprayer that atomized it into a "lesser traveled" part of camp. I'm sure that at a fastidious level, we did cause some droplets of greywater to hit the playa (or personages upon it), but overall it sure beat accidentally stepping into a gooey playa pond or slip& slide (and definitley nice to not have to deal with 200 square feet of sorta-dry definitely-slimy visqueen at the end of the week. The SCM (Sub-Commandante Marcos) setup looks like a huge improvement over that whole mess.

[geekster]

Buy an ice maker. Filter the water and make grey ice. Leave the bags lying around someplace. Someone will steal them. Problem solved.

[backbone]

here's an idea that might solve the "water falling off one side but not the other" problem:

find an old sattelite dish and use that for the top surface (oriented like an umbrella, not a bowl). Paint it black and staple (or drill and lace with wire) the hardware cloth to the bottom edge.

I think some cheap old wood or plastic shims should help the leveling problem.

Instead of using rebar, due to weight and size transporting, I was thinking of using PVC not cemeneted together and drill a few fill holes for filling with water. Besides the diameter of the PVC, my pump requires at least 1" of standing water, does there seem to be any problems with this? Or know of another material to replace the rebar besides PVC?

[Dork]

Besides the diameter of the PVC, my pump requires at least 1" of standing water, does there seem to be any problems with this? Or know of another material to replace the rebar besides PVC?

I'm not using anything to reinforce the hardware cloth at the bottom, and it seems to be holding its shape. I used twist ties to hold the seam together. Hopefully I won't regret this decision.

I had the 1" problem as well. I had some 3/4" plywood scraps laying around so I cut and glued them to the bottom of the pool with a cutout for the pump and painted it black. This leaves less than a gallon of waste to haul out at the end, which I can deal with.

I tested mine last weekend. The pool that was labeled 4 foot turned out to be closer to 3 foot at the bottom, but it's still a decent size. It evaporated 7 gallons in 3 hours so I'm pretty jazzed.

[backbone]

This system worked like a champ! I didn't use the rebar at the bottom to help keep its shape and it worked just fine. I used grabber screws to secure the hardware cloth to the side of the 1/2" plywood as we ran out of staplers. Then I used zip ties to secure the edges on the overlap of the hardware cloth.

I did a 3' diameter plate as that was the available size of the evaporator pool we had and didn't want to go buy a bigger one.

I used quick connects on the pump and the plate. For next year I will bring a garden spayer to quick connect and lightly disperse the last gallons of water.

This year Monday-Wednesday was very windy and thus a lot of dust got blown into the water pond. With the high winds on Mon-Wed. we had a lot of over spray hitting the playa and needed to have a bigger black tarp down to cover for the over spray. Probably need about a 12' diameter area for a 3' diameter evap pool. When the wind died, I plugged in a 24" fan at about 3 feet away to help accelerate the evaporation process.

I had a 1200 gph at 2 feet pump. Forgot the wattage/voltage needs as I wanted to run it off a battery, but the amount of people got larger then 20 people on Friday/Saturday/Sunday that I had to run it about 18 hrs a day on a generator.

Only draw back was the pump required 1" of water so we had to haul about 10 gallons of grey water when we left. Of course if I had brought a garden sprayer, we could have have easily lightly dispersed this on the playa without too much impact.

Thank you for sharing a great solution.

[dragonfly Jafe]

ours also worked well. The only issue was spray caused by wind that blew past our ground cover (9x12 tarp). We had ~35 people using ours for showers and had less than 10 gals on the last day (we also had the minimum water level for the pump to work issue). We easily put that into a few water jugs we brought for the purpose though and all was good.

I saw a nifty evaporator (forget the camp - somewhere near 4:00 and c street I think) - it was a pvc drum like structure with black cloth/canvas sewn into a wrap around it. Additional cloth flaps hung from the drum wrap. A small motor slowly turned the pvc/cloth drum (axis parallel to ground) which dipped the cloth and flaps one-by-one into the water, then they got several minutes in the air to dry. Originally it had a circuit to pause briefly as the rag was in the water, but that had failed. A mechanical cog could do this just as well if not better.

It had no water level limits, no spray, was quiet, and could be easily scaled (by making 2 or more) for any size camp. Unfortunately I had no more film by then. I forget how many people were in the camp, but it was a big one. If anyone knows what I am talking about and has a photo, please post it.

[Ron]

Ours also worked well. To eliminate spray on the playa we ended up wrapping the mesh tower with towels but even so evaporated over 15 gallons of water a day, running the pump around 6 hours while the sun was up.

Worked like a charm, it did. The little bit of gray water we the sun didn't take we put down the toilets of the RVs and had no nasty jugs of the stuff to manage at all.

Ron

[StevenGoodman]

[quote="dragonfly Jafe"]I saw a nifty evaporator (forget the camp - somewhere near 4:00 and c street I think) - it was a pvc drum like structure with black cloth/canvas sewn into a wrap around it. Additional cloth flaps hung from the drum wrap. A small motor slowly turned the pvc/cloth drum (axis parallel to ground) which dipped the cloth and flaps one-by-one into the water, then they got several minutes in the air to dry. Originally it had a circuit to pause briefly as the rag was in the water, but that had failed. A mechanical cog could do this just as well if not better.

It had no water level limits, no spray, was quiet, and could be easily scaled (by making 2 or more) for any size camp. Unfortunately I had no more film by then. I forget how many people were in the camp, but it was a big one. If anyone knows what I am talking about and has a photo, please post it.[/quote]

Jafe, that was where I was camped, Iron Rose. It is based on a modification of design from someone else (Earth Guardians, or AEZ, or someone). I will see if Gerry (who made it) has any pictures.

The PCV was just a lightweight frame. Everything packed into an amazingly small space.

The logic behind the delay in the power circuit was to save power, the drum doesn't need to move constantly. A mechanical cog still requires continuous power?

[Dork]

I spent the first few days fighting with my evaporator. My little 750GPH pump with 3/4" tube was pumping the water too high and the wind would catch it and toss it out of the pool. This was eventually solved by cutting the bottom off a water jug, cutting slits in it, and stapling it over the opening. After this the water still had too much velocity as it got to the edge and was shedding too much, so I took some cloth and wrapped it around the top. This kept it nearly wind-proof, but may have cut down on evaporation a tad.

After this it was pretty much trouble-free except for when everyone in my camp took a long shower late Saturday and filled the thing up, so we wound up taking home something like 10 gallons.

I have some modifications planned for next year - custom wood or plastic base with a bowl at the bottom for the pump to sit in since it needs to be sitting in over an inch of water to run. The kiddie pool had a flat bottom and was a little awkward to pack. The custom piece will be sized to match up with the shower base for easy stowing. I'd like to use something other than a roll of hardware cloth - it's hard to re-roll up at the end. Maybe flat sheets of the stuff, or some sort of fabric instead. One of my campmates also requested an easier way to pour extra water into it, so I may add some sort of sink thing with a strainer.

[motskyroonmatick]

Great to hear everyones evap experiences. I put my evaporator and shower on my flat bed trailer running the shower and pool catch basins to a 5 gal bucket with the 500 gph sump pump in it. I would say it worked excelently except for wind factors and the catch basin for the shower was too small. Next year I will use a second pool for the shower and figure out some adjustable wind activated shut off device. I made a drain for the pool by cutting a hole in the pool, installing a plastic sink drain and a bend to point it over the sump bucket. It worked well but leaked very small ammounts on two occasions. This was remedied by placing a piece of plastic under the drain to direct the flow to the bucket. I think tightening it down with the correct spanner wrench would solve the problem. I tightened mine by hand.
I also did not reinforce the hardware cloth at the bottom and it worked fine. Cutting a hole in the hardware cloth for the water tube did not compromise its integrity. I made a float controll for the sump pump with a bypass so that I could leave it on for the last night on site. This worked well but my camp mates messing with the float /sump pump unit damaged the float switch making it jam occasionally. The addition of noodles in to the system early on made a mess of things requiring cloth to be put at the spill line on the top of the screen. The cloth was later removed resulting in improved functioning. I did have a little trouble with water shooting off the top at startup. It seems that fabric is to tight to facilitate good flow so I may try a bit of window screen just arround the top next time.
My system was solar powered with about 60wat and was able to charge the battery durring the day while the pump was running. This means next year I can run all 12v camp appliances off of one battery. YES! Less weight.
I was able to evaporate shower water for three people daily plus cooler water from 4 coolers and I took in water from surrounding camps at exodus so they would not spill(so much) on the ground. I ended up hauling about a gallon and a half home. All in all I was very impressed, satisfied, and proud of what this great idea can achieve. I must have told at least 10 people about it in detail when they stopped to scope things out.

B.R.C. welding and repair was a tremendous success. It was so much fun helping all of you get your transportation repaired and back on playa.

see you next year!

David

[geekster]

"Jafe, that was where I was camped, Iron Rose. It is based on a modification of design from someone else (Earth Guardians, or AEZ, or someone). I will see if Gerry (who made it) has any pictures."

The original design was one we saw in AEZ last year. That one was smaller, had a longer delay cycle than Gerry's did, and it also didn't have the additional flaps of material. The original was basically a hexagon frame with shade cloth on it to make a sort of drum looking thing where the bottom edge picked up the water. That one rotated a quarter turn and stopped for probably 10 seconds before repeating the cycle. Gerry's had more movement and less delay.

[nocturnal_steve]

We used a short 3 foot tall version, might have reduced wind problems.
The 500 gallon per hour pump was ample. For those of you with bigger
pumps and high wind problems , try clamping hose and restricting flow as needed. A simple plastic (hot and cold) cup having the correct kind of rolled lip, filled and placed next to the upwards water stream helped direct the flow down and out and made a cool fountain effect. I'm going to gussy it up, run with el wire at night, drill some small holes in the ply, do a cascading fountain and place it in front of our camp next year, . The captions in back adorned our rent-a-rv. Thanks El Subcomandante and crew !
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[nocturnal_steve]

Straining kitchen wash water through a stocking or cheesecloth to remove solids and adding a little bleach in the pool tidy's the works up a bit.

[ibdave]

We used a short 3 foot tall version, might have reduced wind problems.
The 500 gallon per hour pump was ample. For those of you with bigger
pumps and high wind problems , try clamping hose and restricting flow as needed. A simple plastic (hot and cold) cup having the correct kind of rolled lip, filled and placed next to the upwards water stream helped direct the flow down and out and made a cool fountain effect. I'm going to gussy it up, run with el wire at night, drill some small holes in the ply, do a cascading fountain and place it in front of our camp next year, . The captions in back adorned our rent-a-rv. Thanks El Subcomandante and crew !

Our's looked almost like your's in the photo, but I use black plastic for the basin and dug a small hole making for a low spot to place the 12v marine sump pump. Worked super duper.

[nocturnal_steve]

Another afterthought, if you were using a high volume pump and had
high spout / wind problems, connecting an adapter and using larger diameter tubing would decrease the spout height while maintaining G.P.H. Also I believe someone mentioned wrapping the tallest part of the screen (as needed in high winds) with burlap or cloth to eliminate spillover. "Nesting" or having a second, smaller diameter inner screen would help too. Again, we had the 3 foot pool x 3 foot high version with 500 GPH pump and had no spillover. Placement - even though it was placed on the on the windward side of our RV, the RV still helped block high winds. We (only) used the sink in our RV (used outdoor shower and BM port-a-potties) so were able to dump all our camp and RV gray water into the evap pound . With intermittent use, average 6 hours a day for a week, we must have evaporated 150 gallons of water. It will be interesting to see how the El Subcomandante / Polando design evolves over the next few years. El Subcomandante / Poland .... the Henry Fords’ of gray water evap !

[Zhust]

I built one as well for our camp (Pulsomnium at 7 and Chance). It was much smaller, built in a hurry with scrap lumber. I bought a small fountain pump (I don't remember GPH but it would deliver a head of 3 feet or so.)

I made a square plywood table with 2x4 legs about 2' high. It sat in a square basin that was made from plywood and scrap 2x8's, about 2'x2' for a total capacity of about 11 gallons. I cut a 6" diameter hole in the bottom of the basin and elevated the basin with 2x4's (which are really 1.5x3x5's) set on their sides. I used a piece of repurposed vinyl billboard material to waterproof it all.

The pump sat in the sump hole as it needed a minimum of 1-1/2" water to run (that is, I stuffed the vinyl through the hole so it was lower than the rest of the basin and stuck the pump in that. I used a garden hose stuck through a hole in the little plywood table and attached it to the pump. I asked someone else for hardware cloth but they brought metal lath for plastering -- no big deal although it was rather sharp; in the end I thought the thickness of the lath (about 1/8") gave the water more surface area.

Anyway, I estimated it was running through about 4 gallons a day. My campmates weren't satisfied -- I didn't realize they thought they were staying at the Hilton and took a steady stream of 5-gallon showers as well as dumping their cooler water into the evaporator. They ended up building a small evaporation pond which handled about a gallon in 3 days; I had to dump it into the evaporator and we ended up having to ship out about 10 gallons at the end.

I definitely recommend the design and also using a rectangular surface. Having rectangular pieces hanging off the sides was definitely a boon for storage. It's tough to tell estimate size-versus-evaporation rates, but even my dinky fountain was cooking through a lot of water. I agree that a debris filter would have helped (the pump plugged a couple times with hair and noodles -- thanks, campmates!) and would add that wide, short evaporators splatter less than tall ones.

[TronaFaerie]

Hey All,

This thing has inspired all of us...including folks in Wyoming and Utah...

I found a pump that is solar powered at http://www.siliconsolar.com that is purpoted to pump 75GPH at a height of 4ft.

I too am planning on building one of these pups, hopefully in time for the Utah regional this year. Lemme know if anyone has any advice earlier.

Lotsa Love,

Trona

[ibdave]

Thanks for the solar site... I'll look into it also... I just might use my 12v boat sump pump with a car battery that has a solar charger clipped to it.. I need about a 5 ft lift.. Thanks again

[Fex]

Wow, I love this thread... you guys are brilliant...

How about scum? Does the cumulative soap/playadust/skin oil/dermal slough/whatever leave behind a film of disgustingness that has to be scraped off periodically? Especially with the airborne dust blowing into the watercurtain?

And how's this idea (pure theory on my part, I haven't done this): What if you put a 12" curved or funneled lip of reflective material (i.e. solar collector/reflector dish style) around the top edge? It would help keep wind from blowing the stream off the side, and do you think the added sun on the black platform would heat the water enough to speed evaporation or would the effect be not worth the extra effort? just an idea.

[motskyroonmatick]

Fex,

I had no problems with very small particulate. I did have problems with noodles and recommend a straining system. The film of discustingness that you mention ended up in the bottom of the pool and sump bucket. It was discusting but required no intervention durring the event. I brought the scum bucket home with me and dumped it down my sewer cleanout. The pool is leaning against my garage getting scrubbed each time it rains and here that is alot.

I don't know anything about reflective evaporation but it would look cool.

I also recomend treating the water with chlorine each day to keep bad smells at bay. If you use the granular concentrated form like I did be sure to tell your camp-mates what it is so that they don't play with it accidentally.

David

[motskyroonmatick]

Bump!

[kyewix]

Check out this guy's wind-powered achimedes screw pump:

http://www.flickr.com/photos/spiritualmonkey/462435791/

[josh riddler]

any thoughts about using a heat conductor like cooper to speed up evap. process

[dragonfly Jafe]

any thoughts about using a heat conductor like cooper to speed up evap. process

....apparently you are thinking along those lines, do tell!

I did proposed a Fresnel lens evaporation greywater system (and aluminum can smelter) a few years back...