There are two camps when it comes to composting toilets: the all-in-one and the urine diverting. Both have their places. Let's look at each to help you better choose which one is right for you!
All-in-One Bucket Method
All solid and liquid materials go in one container, making it helpful for making compost and allowing the toilet to have a simple design. This is the best method if you’re going to be making compost and is ideal for homesteaders and off-grid residences where you have some land to house your compost bins. This is the most environmentally friendly and sustainable choice, since nothing is wasted or landfilled, and beneficial nutrients are added back to the soil where they can be used again.
Urine Diverting Method
Solids go in a bucket, liquids go in a separate container via a urine diverter. This method helps to minimize smell issues while extending the amount of time between emptying the bucket. This is the best method if you’re not going to be making compost, and you’re just looking for a good solution for off-grid use. Separation works well for nomads who don’t have property to house compost bins. Typically, urine is emptied in a public toilet or on the ground (where appropriate), and solids are bagged and put in the trash. While this is not as environmentally friendly as composting your waste, it is certainly better than a chemical toilet, and is more convenient for long-term off-grid use than having to empty a black tank.
For both methods, be sure to keep the bucket contents sufficiently covered with proper materials, and you shouldn’t have any problems with smells or flies. An exhaust fan can provide added assurance that you won’t have any problems with smells inside your home.