Dry toilets proposed for homes spark debate

The dry toilet enters the home: a bucket, sawdust, and waiting

A bucket of sawdust in the bathroom, a trash bag to seal it when full, and the promise that this is the future. The scene, spread on social media and reproduced in thousands of household conversations, has been enough to reopen a discussion that seemed closed since Rome: what do we do with what everyone does daily? The proposal of the so-called dry toilet—separating solids, covering them with sawdust, and composting them—is presented as an ecological leap. The majority response has been another: a regression of two thousand years.

Behind the easy joke lies a serious economic issue. The conventional toilet uses between 6 and 16 liters of drinking water per flush, according to various studies, and this data supports the sensible part of the argument. The rest, the part that has ignited the conversation, is what happens when that bucket coexists with a family in a seventy-square-meter apartment.

How much water does a standard cistern use?

The calculation circulating in the motorhome sector provides a useful reference: the tanks of the most used chemical and dry toilets, those from Thetford, hold around 15 liters and are emptied every few days. Compared to that, a domestic cistern can empty that same volume in two presses. That is the grain of truth in the debate: it is not that the current system is perfect, but that no one has explained how to replace it without losing what already works.

The alternative defended by some sectors is to reuse greywater—from the shower or sink—for flushing, instead of drinking it and throwing it away. It is a plumbing solution, not a bucket solution, and requires giving up nothing. Curiously, it is the least mentioned path.

The problem of odor and public health

The health argument carries the most weight against it. Humanity took centuries to understand that separating feces from human contact prevented epidemics; cholera, several analyses recall, always targeted poorly managed fecal routes. Returning to storing waste inside the dwelling, without chemical treatment, is not a private decision: it is a public health matter.

To this is added logistics. Where does the bag go? To the green bin, the blue one, the yellow one? The question, repeated mockingly, has no official answer. And the domestic scenario described by those who have lived with cat litter boxes—permanent smell, humidity, insects—does not invite optimism. Some point out that the system only makes sense in storage rooms, caravans, or houses with a yard and their own composter.

Cement in the drainpipe and other collateral damages

One of the most commented episodes has little to do with ecology and much with plumbing: sealing the drainpipe with cement to disable the traditional toilet. The solution, besides being irreversible, turns any reversal into construction work. The plumbing service company, some joke, already has its job guaranteed.

The background is a broader discussion about water as a resource. Against those who defend that its public management prevents exploitation, others argue that the problem is not scarcity—the water cycle exists—but the priority given to some uses over others. In the middle, the feeling that what is actually an inconvenience is being sold as a virtue.

An old idea with new packaging

The dry toilet is not an invention: it is the latrine of old, the one in the barn, the grandfather's chamber pot. What has changed is the narrative. Now it is called sustainability, packaged with sawdust, and presented as a conquest. The question left floating is not technical but cultural: why does a society that solved sanitation two thousand years ago accept discussing whether to undo it?

The unsettling fact is not the smell or the bucket. It is that, according to calculations used by some, the resulting compost ends up feeding lettuce resold as organic at premium prices. The circle closes, but not precisely for the benefit of whoever carries the bag.