Tim Gulley

Burton Sparks wrote:I wonder if you could get a flush compost toilet (aka vermifilter) approved.

Good question! I do like the idea of those systems, although I had assumed they wouldn't work in the Cochise County climate since I had heard that the worms die and need replaced if it gets too cold. And while that may be true, it looks like Tiger Worms are used to environments as cold as -40°F!

So I sent Mr. McGee another email inquiring about whether those kinds of systems would qualify under Section R18-9-E320, which references "disinfection devices", and I'll update here if/when I hear back.

Update: Mr. McGee directed me to "AZ dept of Environmental Quality (ADEQ)", so I reached out to them, and after getting forwarded to the right person, a case manager/permit-writer said (in response to my inquiry about vermifiltration and vermicomposting):

So I will need to double check the regulations. I believe that the waste that is produced is considered a biosolid under EPA regulations and would require evidence that certain pathogens have been reduced. Biosolids are usually managed by our water group. Let me look into this over the next couple of days and I will get back to you.

The fact that it didn't immediately get shut down is promising to me, and for what it's worth, I also volunteered to be part of a trial, pilot program that's conditional approval would be based on testing the final product for pathogens. They didn't comment on that part specifically, but I just wanted to make it as open-ended as possible for them since this would be good for everybody, since it's environmentally friendly and negates the need for a septic tank.

More to come...

I can shine some light on this, as I just finished corresponding with Michael McGee, an Environmental Health Specialist for Cochise County Health and Social Services, and he said:

"The 55 gallon drums are used to compost the solids. The septic system is for the kitchen water and urine, consists of the septic tank and leach field. These must be sized to accept the diverted gray water back into the septic system if it cannot be reused. So no 55 gallon drums cannot be used as a septic tank.

If you look at the Arizona Administrative Code (AAC) Section R18-9-E303 <I added the link> there is a table to size the system. Under the column “Minimum Interceptor Size (Gallons)” the first column (Kitchen Wastewater Only (All gray water sources are collected and reused)) as been removed by the State. We can only use the other column since 12/1/22. So the minimum interceptor size is 200 gallons."

In other words (especially when combined with the previous conversation that I'm not including here), the 55 gallon drum composting toilets are approved by the State, but you need more than just that in order to account for the black water from the kitchen sink, and apparently urine too. And for that purpose, 55-gallon drums are no longer approved (for no specified reason).

... But it's at least nice that the minimum is 200 gallons instead of 1,000 anyway.

As for me, I think I'll probably just use my RV black tanks in combination with the permitting for that, and then just dump my tanks every couple weeks at a local campground or whatnot until I can work a full blown septic system into my budget.