Hi folks, I'm new here. I hope I am not posting about a topic that has already been beat to death elsewhere! Here is an essay that I have been writing that partly summarizes the legality of making your own composting toilet in Washington State. Enjoy, comment, ask questions...
I made my own composting toilet, and I encourage others to do the same. Here is my most recent, but still outdated, YouTube video
Okanogan County Public Health has not permitted my composting toilet, yet. I can blame myself for telling them to basically leave me alone instead of having a conversation with them about getting it done legally. Hopefully, this essay will help folks to get the conversation off to a more successful start. The most important document about making your own composting toilet legally in Washington State is the Department of Health’s publication #337-016 Recommended Standards and Guidance (RS&G) for Performance, Application, Design, and Operation & Maintenance Water Conserving On-Site Wastewater Treatment Systems. Public Domain (not subject to patent) composting toilet systems are legal (RS&G 2.2.2.). I recommend looking at Joseph Jenkins’ and David Omick’s public domain composting toilet systems for ideas on what might work best for your location. The next rule you will need to consider is the Department of Ecology’s WAC 173-308 Biosolids Management on what to do with your poo when it is ready for distribution (the federal rule that the state law is modeled after is 40 CFR 503). If greywater is produced at your location for showers, laundry, sinks etc. “an approved on-site greywater treatment and dispersal system, or public sewage system” is still required (RS&G 3.2).
There are various types of user built composting toilets, but one distinction to consider is whether the composting will take place where it touches the ground, or if it will take place inside of a container that does not leak water. Section 3.6.1 of the RS&G says that “For composting toilets installed entirely within a structure or a service vault, there are no specific set-back requirements” (i.e. distance to wells, creeks etc.). Here are those distances: (WAC 246-272A-0210 table IV) 200 feet from a public drinking water spring; 100 feet from a public drinking water well; 50 feet from a well, suction line, or surface water measured from the ordinary high-water mark; 10 feet from a pressurized water supply line; 5 feet from a property or easement line. If one or more of these water sources are too close to where you want to compost, I recommend checking out David Omick’s website Omick.net “Barrel Composting Toilet System” or YouTube
Note that Omick lives in Tucson Arizona. In cold climates you will need to keep the barrels above 65°F or nearly double the number of barrels as they will be considered excrement storage units during cold weather (RS&G 4.4.5.). If wells, creeks etc. are not too close to the planned compost area, consider Joseph Jenkins’ composting method. It is possibly less expensive, and easier to achieve high temperatures which kill pathogens. Jenkins’ full website is Humanurehandbook.com, or more briefly see his Sanitation Paper, or YouTube
Before you distribute your compost, you will need to decide if you will manage it as domestic septage (WAC 173-308-270), which it is automatically considered, or biosolids (WAC 173-308 -210 or -250), which requires more testing and can be used on lawns or home gardens if it is Class A with respect to pathogens. Septage from composting toilets are exempt from the reporting requirements in WAC 173-308-295 and the permitting requirements in WAC 173-308-310 (WAC 173-308-193). Domestic septage must be incorporated into the soil (WAC 173-308-270 (3)(ii)). I will be placing my compost on native perennials which will die and turn to weeds if I disturb the soil, so I plan to manage my compost as biosolids, not septage. Which includes: not exceeding pollutant limits by not putting heavy metals into my compost (WAC 173-308-160); removing or not putting in plastic, glass or metal (WAC 173-308-205); significantly reducing pathogens by maintaining a thermophilic (> 113°F) compost pile—hold above 131°F for at least 15 days after the last poo of the batch is added (at least two bins or barrels are used to enable batch composting) (WAC 173-308-170 (3)(i)(B)); vector attraction reduction will be accomplished at the same time—113°F for 14 days (WAC 173-308-180 (3). Biosolids, and Septage, must be tested for at least nitrogen and applied to not over fertilize. Biosolids, not Septage, must be tested for pathogens (< 2 million fecal coliforms per gram is class B, < 1000 fecal coliforms per gram is class A) (WAC 173-308-170). Class A biosolids can be placed on lawns or home gardens (WAC 173-308-250). I plan to test my compost for nutrients and E. coli at Soiltest Farm Consultants, Inc. in Moses Lake for about $170. To find other approved labs, search for Washington State ecology lab search (search by matrix, solid and chemical materials).
Ensure that the compost maintains a moisture content of about 60 percent. Moisture content below 40 percent will slow decomposition and will increase the likelihood of fire ignition—you can be held liable for fire suppression costs (RCW 52-12-108 ). Moisture content above 75 percent will lead to anaerobic conditions (or not having adequate oxygen) which will slow decomposition and cause objectionable odor (hydrogen sulfide and ammonia) which must not migrate beyond property boundaries (WAC 173-350-220 (1)(c)(iii) and potent greenhouse gasses (methane and nitrous oxide).
Septic rule review is required every four years, and 2017 is the next review year, so now is the time for people interested in changing septic law to look at what specifically they want to change and speak up (WAC 246-272A-0425).
Hope this was useful info. It is complicated and still only a partial summary of the law. Cheers!
Cannot thank you enough! This was exactly the information I have been looking for to help in our composting toilet plans.
Location: Tonasket, WA
posted 2 years ago
Great news! I received my biosolids test today, and it passed! It had 21 most probable number per gram of fecal coliforms out of a limit of 1000 MPN/g. I'm a bit skeptical of authority (EPA CFR503) so I tested freshly cut grass clippins from Bud Clark Field, a baseball park in Oroville washington for comparison, and I can't guaranty that a dog did not use that patch of lawn as a bathroom BUT > 53200 MPN/g!!! This result is consistent with Washington State Department of Ecology's note that salmonella and fecal coliform bacteria are commonly found in lawn clippings and yard debris (Siting and operating composting facilities in Washington State p10). A salmonella test for an extra $75 or an E.coli test for an extra $25 would give a more meaningful result as some "fecal" coliforms are not harmful. During summer 2015 Okanogan County had extreme fire weather, and I did not have an adiquit water supply to safely maintain a thermophilic (> 113F) compost so I avoided adding green vegetation to avoid starting a fire. I put in urine, chicken manure and dead animals. It aged from November to July. Cheers!
Very good news, I am glad I caught this thread as I just got 40 acres outside of Oroville and am planning to do a composting toilet system. Good to see you have laid the ground work in the area. I went the route of buying a commercial composting toilet from C-Head as I was told by the county that getting it permitted was much easier than a DIY one. But I would like to add some DIY built ones too in the future as I build my home.
"Where will you drive your own picket stake? Where will you choose to make your stand? Give me a threshold, a specific point at which you will finally stop running, at which you will finally fight back." (Derrick Jensen)
Location: Tonasket, WA
posted 2 years ago
County extension offices often have recommended fertilizer application rates for various types of land use. I chose to apply less than 30 pounds of nitrogen per acre, and my compost contains 0.61% (wet) nitrogen, so I can apply about 2 tons per acre to get 24.4 pounds of nitrogen, or my 250 pounds of compost will fertilize about 1/16th of an acre. Many land uses will require more fertilizer than my dry grassland/ponderosa pine woodland.
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