Composting Toilet by the book
July 22, 2017 2:30 PM
We want to build a composting toilet to meet all of the relevant requirements in our area (Portland, OR). The requirements are confusing, though, and state/local building officials tend to throw up their hands and say "I don't know!" when we ask questions about how to design it. Can anyone help clarify these several, sometimes conflicting, standards, or recommend a way to get good answers?
The plans for our house (still under construction) were approved under the 2011 Oregon Reach Code, which sets certain prescriptive standards for site-built composting toilets. The senior city plumbing inspector, however, doesn't know anything about the Reach Code and referred us to the city's Alternative Technologies people, who are less resistant to the idea of composting toilets but know little about plumbing. They, in turn, referred us to the state Plumbing Chief.
The state Plumbing Chief knows a little bit about composting toilets, but said Oregon Administrative Rule 918-770 supercedes the Reach Code. I'm kind of surprised, because OAR 918-770 seems to have been written in 1997... so why did the Reach Code get approved in 2011?
Anyway, OAR 918-770 refers to NSF 41 (a 1983 standard for certifying commercially-produced composting toilets), and that is what the state Plumbing Chief seems to consider the ultimate reference. He said he'd do some research on how to meet that standard, but hasn't been returning calls.
So: Which standard should we be looking to? And/or what public official should we see about untangling this mess?
Bonus: Would we be able to cut out some of this with a design stamped by an engineer? If so, what kind of engineer?
The plans for our house (still under construction) were approved under the 2011 Oregon Reach Code, which sets certain prescriptive standards for site-built composting toilets. The senior city plumbing inspector, however, doesn't know anything about the Reach Code and referred us to the city's Alternative Technologies people, who are less resistant to the idea of composting toilets but know little about plumbing. They, in turn, referred us to the state Plumbing Chief.
The state Plumbing Chief knows a little bit about composting toilets, but said Oregon Administrative Rule 918-770 supercedes the Reach Code. I'm kind of surprised, because OAR 918-770 seems to have been written in 1997... so why did the Reach Code get approved in 2011?
Anyway, OAR 918-770 refers to NSF 41 (a 1983 standard for certifying commercially-produced composting toilets), and that is what the state Plumbing Chief seems to consider the ultimate reference. He said he'd do some research on how to meet that standard, but hasn't been returning calls.
So: Which standard should we be looking to? And/or what public official should we see about untangling this mess?
Bonus: Would we be able to cut out some of this with a design stamped by an engineer? If so, what kind of engineer?
Try the folks at Recode Oregon. This is their baby and they actually wrote some of the relevant codes (including the most recent UPC Green Supplement sections on site-built composting toilets). Failing that, call Tyson Wilson (plumber specializing in eco-friendly stuff). Failing that, me-mail and I'll reach out to one of my other contacts and/or figure it out myself.
Qualifications: 4th year union apprentice plumber in Oregon.
posted by cnidaria at 3:55 PM on July 22, 2017
Qualifications: 4th year union apprentice plumber in Oregon.
posted by cnidaria at 3:55 PM on July 22, 2017
cnidaria - Thanks for the suggestions! We've been in touch with Recode, but I should probably check with them again now that we have a little more info. When we talked to Tyson Wilson about this project a few years ago he didn't have much to say on it, but I'll give him a call and see if he knows more now. I just went to check the most recent UPC Green Supplement, but I'm a little hesitant to spend $65 on it when I have no idea if it would be relevant to us. I'll see if Recode has a copy of those sections I could look at.
So I guess I'll check with Recode and Tyson, and maybe get back to you depending on how that goes. Thanks again!
That said, I'd still appreciate more ideas/resources/suggestions in this vein!
posted by sibilatorix at 4:22 PM on July 22, 2017
So I guess I'll check with Recode and Tyson, and maybe get back to you depending on how that goes. Thanks again!
That said, I'd still appreciate more ideas/resources/suggestions in this vein!
posted by sibilatorix at 4:22 PM on July 22, 2017
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ALTHOUGH, you really need a grey water system for pee. You need a dry or waterless urinal because no one wants to carry buckets of poop AND pee around. You need to separate the pee so it doesn't weigh the bucket down. I think an adult male can produce a gallon of pee a day. so 2 or 3 people in a house - that's a lot of pee! So you need a grey water system and for that you will need approval and plans and I think a lot of places have a "greywater" department. In California where they have had drought they are organized about this - maybe not in Portland.
Shouldn't you be talking to local tiny home builders/community about this? Seems like they would know.
posted by cda at 3:08 PM on July 22, 2017