When we last talked to Mike, the Eldorado State Park employee with the human waste (aka poop) problem, he was attempting to introduce redworms into the system. He was planning to start small and see how the redworms reacted to the environment they are in.
I followed up with him in mid June (the start of the really busy season for Eldo) and he had this to say:
The worms are pretty doggone happy. There’s the can where they get raised
in cardboard, soil, and food scraps, and that population is doing well. I
was initially worried about the worms in the sh***er because I couldn’t see
them – but with some excavation, I found them down about a foot in the pile
of poop and wood chips. They’re thriving.
I’m still a little gunshy about introducing the effluent to some worms. I
guess they’ll turn their noses pretty quick if they don’t like it.
The temperature in the experimental vault is rising slowly (90 degrees as
opposed to 60 for the control vault). I’m doing the humanure approach and
adding plenty of greens and sawdust. Honestly, it’ll probably take years to
get that pile cooking – it’s a giant mass of dead, anaerobic, cold waste.
My (adapted) plan at this point is to keep at it with worms and the humanure
approach. Best case scenario: Some combination of heat and osmosis will
start drawing water up into the pile to get hot and evaporate. Worst case
scenario: thermophilic & vermicular composting produce wastewater that
beneficial for vegetation and I can start using that “waste” water in the
park for new plantings, etc.
In short: Worms alive and well, and the sh***ers are learning adventure in
progress.
It sounds like he’s mixing it up–along with the redworms, he’s doing some humanure composting (probably based on The Humanure Handbook–well worth a read if you haven’t checked it out).
I’m thrilled that this experiment is going well. Will keep checking in with Mike in the future.
June 30th, 2010
Update 2/7/2010: Just so you know, there are some graphic pictures below. If you aren’t interested in viewing humanure, please don’t read further.
Last week I had an interesting meeting with Mike, an official at a local state park. They have a desiccating toilet that just isn’t working as well as they had hoped. Here’s a picture of the toilet system from the outside.
Eldorado Canyon State Park Bathrooms
Below is a picture of the system from the inside. They have two large plastic vaults that have air flowing from the outside into them. The feces and toilet paper are held up via a metal trough, and air flow drys them out. Wood shavings are regularly spread in the system, which is supposed to help control odor (I think). Finally, the entire mass of poop is regularly sprayed with fresh water (on a timer). That is supposed to help decomposition. (I don’t understand how the water spraying and the air drying work together, and neither did Mike.)
Eldorado Canyon Desiccating Toilet System
Below is a picture of inside the system. Yup, that’s human feces and toilet paper. I visited during the winter, and the level was not high. Mike said that the entire mass freezes solid during the winter. The white horizontal line in the middle of the picture is a tool that lets someone distribute wood chips or move poop.
Inside Eldorado Canyon Toilet Vault
The primary issue with the toilet is a high pH leachate that accumulates at the bottom of the system, below the trough. Eventually that liquid gets so high that the system needs to be pumped. You can read his description of the issues; he goes into far more detail about what has been tried. He also summarizes what we discussed and the plan moving forward:
- I’ll build a compost bin, in the basement with the vaults, loaded with worms.
- I’ll get the worms started with food scraps from the office.
- I’ll make some experimental sections in the worm bin, and try adding some of the, er, material from the devap toilets, and maybe try soaking a different section with the excess water. The idea is to see what the worms like and thrive on.
- If the wigglers like human waste, but not the bilge water, then I’ll leave the vaults unmodified, add worms, and let ‘em go to town this summer.
- If the wigglers like human waste AND the bilge water, I’ll add worms to the vaults, and scale up by periodically pumping some of the waste water up into the stack.
- Worms will crawl and explore, but they also like dark and quiet. It’s highly unlikely that they’ll crawl up to the main floor.
- If the worms are successful, they’ll probably die off every winter in the cold vaults. The warm, freestanding compost pile will have to be maintained during the winters.
- It’ll be interesting to see what happens with the odor.
- I’m totally rooting for the worms. It would be phenomenally cool if worms could thrive on the wood chips, waste, and wastewater.
It will be interesting to see how the worms adapt to a diet of human waste. I found some links that indicate that they should do alright (thanks, Google Scholar!). Here’s one on a worm composting outhouse, which discusses some of the unique aspects of vermicomposting human waste (as opposed to the more typical feedstocks of yard and kitchen waste):
The worm bin should be operated like any worm bin. The moisture, temperature and aeration needs are the same. One difference is that human waste has a Carbon to Nitrogen ratio of 20:1 and so it needs a high carbon material added to decompose best.
Here’s another article discussing using vermicomposting to stabilize sewage sludge. Here’s an article about redworms reducing pathogens (a topic I reviewed last year). This is an interesting article on how feedstock affects E. Foetida weight and length (pdf). And here’s an interesting abstract for an article on the effects of stocking density and feeding rate on biosolid vermicomposting that is worth excerpting:
Specifically, the focus of this study was to investigate and establish an optimal stocking density and an optimal feeding rate for the vermicomposting of biosolids, with paper mulch provided as bedding. A stocking density of 1.60 kg-worms/m2 (0.33 lb-worms/ft2) and a feeding rate of 1.25 kg-feed/kg-worm/day resulted in the highest bioconversion of the substrate into earthworm biomass. The best vermicompost was obtained at the same stocking density and a feeding rate of 0.75 kg-feed/kg-worm/day.
Based on reviewing these articles, a key component of this system will be adding enough carbon to keep the worms happy. The main source of carbon currently is wood shavings, but they are purchased. I think that shredded paper and/or leaves would be good alternatives. Some calculations should be made to determine how much bedding substance to add.
In addition, redworms need a pH between 5 and 9, and I believe the leachate was well above that (update 2/7/2010: per a conversation with Mike, the pH of the leachate is 8.5 or 9). I don’t think the worms will be able to process or reduce that liquid directly. However, the source of the leachate seems at first blush to be the fresh water spraying, so if the worms process the waste and help maintain humidity, less spraying may be needed, and thus less leachate may be created. Even if the same amount of spraying is required, the worm castings may retain more of the water, and reduce leachate in that manner.
I’m a huge fan of Mike’s plan to start small (with a 55 gallon drum) and see how the redworms react to waste and/or leachate. This experimentation will be cheaper and easier to control, as well as giving Mike a chance to become familiar with worm keeping.
February 2nd, 2010
I just returned from the third annual Rocky Mountain Compost School, four days of classes about compost in Fort Collins. It was quite interesting, though definitely not aimed at home vermicomposters, home composters, or vermicomposters in general (I think the North Carolina Vermiculture conference would be a better be for vermis). The focus was on industrial composting, and all the intricacies therein.
I’m not complaining–there was a ton to learn and the conference was never billed as a home vermicomposting conference. Most of the attendees (there were about 20) were from Colorado and Wyoming municipalities that were composting or were thinking of composting. There was an attendee from the EPA, some environmental consulting companies, someone from Waste Not Recycling, two farmers, and me.
Among other things, I realized that instead of sending my worm castings to a soil lab to find out their chemical content, I should have sent it to a compost lab. One of the speakers, Will Brinton, runs Woods End, which does compost testing among other things. He mentioned that there were only seven labs capable of analyzing compost in the United States. (Europe has ~200, and compost running out of their ears, apparently.)
Large scale vermicomposting of biosolids, municipal waste, and yard waste doesn’t appear to be happening locally. If you are composting more than 100 cubic yards of waste yearly, the Colorado Department of Public Health and Environment regulates you, heavily . Wyoming doesn’t have any such regulations, and Illinois has some of them. Apparently, the EPA 503 rules, which deal with biosolids (humanure), are the starting point for many regulators, but each state then layers on their own regulations.
The class spent some time talking about compost tea. Again, this was specific to compost, and not to vermicompost, but I was amazed to learn that the main research focus of compost tea has been on increasing plant resistance to pathogens, *not* on increasing nutrient delivery to plants. Also, the common practice of adding sugars to compost tea during the brewing process actually increases the viability of E. coli (if any E. coli is present in the compost). And the bubblers that are often sold are overkill–simply stirring the compost tea three times a day with an oar is enough aeration.
Some of the other interesting talks including what it took to make compost that was certified as organic, experiences with composting dead animals, how applying compost to Colorado soil affected pH and organic matter, and the various standards and lack of standards in the compost market. There was also some hands on exercises and demonstrations: the class made and monitored a compost pile, measured the water content of compost, saw how to use the Solvita compost testing kit, and used a spreadsheet to build a compost recipe.
The class also toured two different municipal composting facilities (Cheyenne, WY and Boulder, CO). It was great to have a chance to ask questions of people on the ground, doing real industrial composting. Another interesting tidbit was the US Composting Council was started as a way to deal with the public relations problem of disposable diapers.
A highlight, for me, was visiting John Anderson’s worm farm but I’m hoping to get another post up with some pictures from that visit, so I won’t go over about that.
Compost making seems like a relatively young science. Brinton mentioned several times that there was a large amount of disagreement in many aspects of compost, including what it actually is, how the process works, and how to characterize it in terms of quality. There are few nationwide standards, and any group can put out their own standard (as a group of Colorado composters did a while back). The class was fascinating, and there’s a ton of work being done.
My overall takeaways from this course:
- finding a market for compost is the most difficult part of the process, but there are markets out there
- large scale composting is real and happening
- large scale vermicomposting is not prevalent, at least not around here
- compost nutrient value and process depends highly on the purity of ingredients
- there’s no ‘one way’ to make compost–how you make it depends on your end use
April 18th, 2009
This is part 3 of my interview with Forest. You can find part 1, where Forest discusses a large scale vermicomposting system he worked with in Hawaii, and part 2, where he discusses his more recent failed attempt at keeping worms in the kitchen.
Here we finish up and discuss a wide range of topics, including:
- Forest’s view of worms in permaculture
- the new curbside composting program here in Boulder
- whether he intends to work with worms in the future
- what blueworms are good for
- worms and human manure
- keeping redworms warm through the winter
- and anti-depressants in Manhattan’s drinking supply.
Dan: I really love the fact that you were part of a real business [the worm farm in Hawaii]. Do you know, did you look at any numbers from that?
Forest: No, we never sat down and did figures around it. We just were more interested in the systems than we were in the finances around it. And there wasn’t a lot of expenses involved. I constantly questioned using fossil fuels to pick up compost and bring it back. Because some days it made sense because we were going in to town anyways but some days we only went into town just to get compost to bring back and I definitely did question it. I didn’t sit down and run the figures though.
D: Well and the labor. I assume you were all living there with free room and board
F: Yeah, some of us were being paid. Some of us weren’t. Most of use were work-trade. So we worked a certain amount of hours a day to be there, to be able to eat there.
D: I mean the one huge cost that comes right to mind, aside from fossil fuels, in terms of driving is labor, in terms of picking stuff up and dropping stuff off.
F: I mean luckily since it is Hawaii it’s really easy to get people to live there for cheap. What the owner did was he bought people’s plane tickets and then had them work it off, plus work a certain amount of hours per day to be there, and to be able to eat. So pretty much paid people didn’t have to come up with any capital on their part
D: What’s the place called?
F: And he got cheap labor.
D: Sure.
F: What did they name the farm? I don’t remember what they called it.
D: Are you planning to continue your experience with worms? Or like right now, in your current situation?
F: In my current situation, I’m not. If I had some property, yeah for sure, I mean worms are an important part of the ecosystem. We’re only taking red worms here. But in the tropics they have a blue worm, which we were working with also. Blue worms eat compost quicker. They’re more aggressive. Like if you go at them, they’ll jump at you, they’ll actually throw themselves at you.
D: Same kind of size?
F: They’re larger, they’re kind of blue grey. They’re tough little ones. What we did is we create a syste munderneath the chickens where they roosted at night so all of the their crap fell on top of the worms and then we’d put shredded paper on top of that and then kept it covered with chicken wire in so the chickens couldn’t get access and they processed all the chicken poop. So it was fresh and hot and they ate it all.
D: Really?
F: Yeah. They’re intense little worms but they’re only really suited to the tropics.
D: Cause they’ll get cold?
F: Yeah they’re really sensitive to cold. The red worms you can bring into the Tropics or here. I know there’s on the east coast the red worms have escaped to natural environments and actually caused a lot of issues because they eat things too quickly in certain ecosystems so I know that’s one thing to watch out for but it’s not an issue here in Colorado.
D: Are you sure?
F: I mean, from what I’ve heard.
D: I’ve been thinking about calling the extension office.
F: You should do that. From what I’ve heard Its too cold in the winter and not enough plant material in the wild to support them. It was on the east coast with a lot of leaf matter.
D: Sure.
F: They were able to go through that really quickly, consume it too quickly? I don’t know exactly all the ecology around it.
D: I actually found a website, or I was on a mailing list that sent a website out about that in the Great Lakes region, in Minnesota or Wisconsin. They actually have a website saying don’t release your red worms to the wild because it really does change the nature of the forest.
F: It can. It depends where.
D: This is of course an advocacy website centered in that region. They said, you know be aware of this.
F: Yeah yeah.
D: Not sure about Colorado. What are you doing with your food waste now?
F: Now I am putting them into a 5 gallon bucket and when that’s full I’m bringing em to where I work at and just throw them on that compost, which is a little more management, you know hauling it around but I don’t really have any other options.
D: Sure sure. Are you excited about the Eco-Cycle composting that’s going to come in? [note: I was wrong, it's not an Eco-Cycle program--it's a city of Boulder program]
F: Somewhat. I wish that they would introduce, I wish they would give, they would do more teaching people how to do more composting. Rather than just being a consumer of compost, giving people one more trash receptacle to throw everything, I’d rather see people have compost in their backyards because, pretty much unless you live in an apartment building you can have a compost. I could probably have one actually if I wanted to invest in one of those big black ones I could find a corner in my apartment building. Something like that. But I’m not too excited about it but I’m glad they’re trying to get that out of the waste stream also.
D: Sure.
F: So I’m alright with that.
D: Yeah. Cool! Well do you have any other things? We’ve got a good amount of time. Do you have any other parting thoughts, anything else you would say about worms?
F: They’re an important part of permaculture. They’re really important in order to manage waste effectively. The combination of the chickens and the worms was just incredible.
D: In terms of destroying large amounts of food waste?
F: Yeah. Transforming that very quickly and efficiently. You know I mean literally you can take all your waste, throw it into, just your plant based waste, into your chickens and right then you’re getting eggs and meat back and then it goes throughout your worms and then you’re getting the nice rich source of your compost too. So it’s nice because the chicken shit, if I can say that, gets mixed up into the compost also, and that gets put into the worm system too and that’s one way to handle that waste too. It worked well, it worked well. There’s some management in it, management of temperature, humidity, and I’ve never found a nice composting system, like already pre-manufactured. Oh, no, I used to own one of those black ones, they have multiple trays.
D: Ok.
F: ‘Worm hole bin’ or something they call them, or ‘bin o’ worms’? I had that five years ago. I didn’t manage it very well. I got fruit flies also, but it does take some management and some tweaking to figure out a good system. And I’m kind of now more in the lines of not necessarily having to give them their special spot but actually incorporating them into the compost. Because what I’ve learned about them is if they’re in your compost and there is nothing to eat they’ll come out and they’ll start looking for other sources of food actually.
D: Red worms will?
F: Yeah. Also, red worms you know compost outside. Cause one of the problems with most bins is they’re too small to hold heat in the winter. So they get killed in the winter. If your normal compost pile is a good size, it’ll keep heat all winter and actually they’ll go into the center and live there.
D: That’s actually been my experience because I have a 3×3 black plastic compost bin and I had a 2×2 wood worm bin where they actually lasted, this was 2 years ago or 3 years ago, they actually lasted almost through winter except when we had like a week of really cold temps, they all froze and died but, last winter, these guys in the compost bin were a-ok. I mean I’ve looked at [another classmate's] worms and her kind of special worm bin, and they’re much happier than my worms. I still have plenty of worms. And so maybe mine isn’t the optimal environment but it’s very low maintenance.
F: That’s nice. Yeah its definitely something to think about, is the level of management involved in it.
D: I don’t know about you but like when I first got worms I was checking on em, you know, every day. I was really interested in how they’re doing and then now, I’m just really glad that they do their job.
[laughing]
F: Yeah yeah, now in Hawaii, there were some people experimenting that we had talked to, and I never saw any of their systems, with composting all their human waste with it, also. So they collected their own waste into 5 gallon buckets, that they went in and layered it with sawdust and then they put that into special bins and they had worms and they let the worms work that for a year and they were then using that on their plants.
D: I assume … Everything I’ve ever read about human manure is you put the resulting compost on fruit trees or you know, not on leafy vegetables.
F: I know people who do it on leafy vegetables. Because the problem is… that’s a good rule of thumb, to only do it on fruit trees. It’s just playing it safe. But as long as you reach the proper temps or a certain length of time it’s totally alright. It’ll break down into just soil. It’s the E. Coli is why they don’t want you to do it onto leafy vegetables. There is a threat of it spreading. As long as its properly decomposed it’s not an issue. The Humanure book? I don’t know if you read it?
D: I think I browsed through it at class.
F: I’ve read that book all the way through and they do put it on their whole vegetable garden. The authors. But they let it sit for two years and properly break down. They layer their compost properly, they have it on there and leave it alone for two years and then they use it. But by then there’s nothing in it that would cause problems. It’s the length of time, it’s the temperature.
D: From what I’ve read is people use their municipal sludge on farms too. So yeah.
F: It’s legal. That doesn’t make sense to me. To me, part of it’s the chemicals that people flush down the drains, that what always concerns me.
D: Sure sure.
F: You know in Manhattan’s water supply they found anti depressants?
D: In the tap water?
F: It’s detectable in Manhattan tap water because they recycle the water from the waste stream and that stuff doesn’t break down. The chemical structure doesn’t break down and so by the time its processed and chlorinated and all this stuff, it’s still detectable in the water supply. It’s scary, isn’t it?
D: That’s really scary. I’d love a further conversation with you about just general systems, natural systems and what we gain out of them because it’s something I’ve really been interested in learning more about but not tonight. Well thank you very much, Forest.
F: Thank you.
January 28th, 2009
