Composting Toilets

The book Everyone Poops states an obvious fact, and so humanity has forever been forced to answer the question: what do I do with this shit? Literally. Throughout history, societies have come up with a range of strategies to dump what’s been dumped, from burying it in pits to simply letting it run in the streets. For those of us born into the affluent West within the past 250 years, however, there has been only one acceptable system: the flush toilet.

Forget What’s Your Poo Telling You? (does it float? Gassy stomach), the flush toilet took a giant pair of shears to the connection between ourselves and our waste. Simply make a deposit, and a magical current of sparkling, drinking quality water will whisk all evidence away, to a never-never land, the great sewer in the sky. The flush toilet officially makes your poop Not Your Problem.

Certainly there are health and hygiene benefits to be found in separating human populations from mountains of fecal matter. But the system we have become dependent on to solve this issue was never going to be sustainable. Its basis lies in taking clean potable water, polluting it, then using more energy to clean it from the waste we added.

According to U.N. water statistics, conventional flush toilets in middle-class households account for approximately 30 percent of global water use.
According to U.N. water statistics, conventional flush toilets in middle-class households account for approximately 30 percent of global water use.

Or worse, the sludge is dumped into in a river or ocean where a normally very beneficial and nutrient rich mix creates havoc on the water ecosystem.

The flush toilet was thus perhaps the most harmful, least beneficial and yet most celebrated invention to ever be celebrated as a success of “development.” These seemingly luxurious seats of porcelain take a helpful, nutrient-filled substance and turn it into waste, while dirtying clean drinking water. The traditional toilet where it’s mixed with fresh water and thrown away just doesn’t make ecological sense.

There is evidence of water-powered sanitation systems even in archeological sites dating from the 31st century BCE, in Britain’s Skara Brae, Orkney, but it wasn’t until the 1850s that our familiar, clean water-intensive toilets became widespread. Since then, people have polluted an obscene amount of drinking water by using it as transportation for their waste, not to mention using energy and polluting through our bathrooms. Americans alone flush 4.8 billion gallons of water down their toilets every day. The waste from water toilets accounts for 90% of each household’s environmental pollution, and toilets account for about a quarter of the average home’s water use.

Skara Brae house site, Orkney Islands. There is evidence that water was piped under the settlement, possibly for sanitation.
Skara Brae house site, Orkney Islands. There is evidence that water was piped under the settlement, possibly for sanitation.

Luckily, after only a few generations, people are beginning to realize what an error we’ve made, and are designing toilets that combine ancient understandings of human waste’s potential with current sanitation technology.

Enter: the composting toilet.

A composting toilet is a dry toilet that uses a predominantly aerobic processing system that treats excreta, typically with no water or small volumes of flush water, via composting or managed aerobic decomposition.

By installing a composting toilet, you can transform your waste from environmental problem to solution. These toilets eliminate the use of water, instead transforming waste into compost through aerobic decomposition. The benefits to you and the environment are enormous. A compost toilet will provide you with a constant source of quality soil, save you money (installing a compost toilet costs 25-75% less than a septic system), and spare waterways the harmful runoff from common sewage systems.

After the initial time to get over any lingering squeamishness you might have after a lifetime of seeing your waste magically sail away, the transition to a composting toilet doesn’t have to be difficult at all.

There are two main types of composting toilets: self-contained appliance toilets, which compost waste directly under the toilet seat within the room, and central systems, also called remote or bi-level, which transport waste to a container located in another location. When preparing to make the switch, first consider what your space is like. Do you have enough for a bilevel? Do you have access to an adequate supply of energy, or will you need a passive design? Compost is catalyzed by heat, so consider whether you can put your toilet in a heated room or will have to heat and insulate your toilet separately? Consider locating your toilet next to a south-facing window or near a heat-generating machine to effortlessly increase its temperature.

Composting toilets appear similar to flush toilets. Their structures range from simple boxes to familiar ceramic seats, many of which have two chambers to guide the separation of urine from feces. After each use, all composting toilets require additional input of a cover material, such as ash, peat moss, or wood chippings. Bacteria and fungi then work their magic to alchemize human waste into humanure- a rich, humus soil, which is 10 to 30 percent of the original volume.

Composting toilets range from multi-thousand dollar high-tech machines to buckets with a toilet seat. Self-contained units allow waste to decompose right under the toilet, and must be emptied, while more complex remote systems funnel waste to a further location, perhaps a basement or backyard. Most pre-built composting toilets cost around $1,500 to $3000but pay for themselves in avoided water and sewage bills. Many high-tech toilets include special features to catalyze decomposition and prevent odor, including heating units, injected air, air baffles, and worm units. These add-ons will naturally require some energy input, however. A simpler model, built yourself, can be as cheap as the materials you can salvage.

Adding a composting toilet to a New York City residence is not easy. Eco Brooklyn has done it when we do gut renovations. We did it in a brownstone and in a shipping container building. The reasons for doing this in Brooklyn or NYC are primarily to reduce the flooding of the rivers with sewage when it rains.

In places outside of the city it makes even more sense. If you are in a place that uses ceptic systems then the reasons are even greater.

If you’re ready to take the plunge, you have a variety of options:

You can build your own.

Instal an Aquatron system to decompose your waste at a distance or in your basement.

Buy one of Envirolet’s dual-fanned toilets.

These are half the price of most models.

Sun Mar produces self-contained models if you don’t want a separate holding tank.

A less expensive, simple box design.

A high end firm that consults and installs their own designs.

A New York and Brooklyn Composting Toilet Installer: Eco Brooklyn. These gays are amazing.

One unfortunate hurdle to installing a composting toilet is that, as with any building project, you must apply for a permit, and since they are relatively unknown in the United States, composting toilets sometimes face ignorance-induced discrimination from the local department of building (DOB).

This happened to Eco Brooklyn when we applied for a permit to install a composting toilet with SunMar. The DOB denied us because of concerns that it might release too much carbon dioxide, despite the fact that composting toilets are vented like any other toilet. Bottom line, their response was not based on fact: they didn’t know how a composting toilet works so simply denied it. A bottle of sparkling water releases more carbon dioxide into a house than a composting toilet. And besides, who cares. Carbon dioxide is hardly dangerous to a home.

Once installed, a composting toilet requires slight maintenance. Frequent addition of carbon heavy organic material is the most frequent maintenance, but think of that cupful of sawdust as the equivalent to a flush. Composting toilets will only clog if you overload it at a pace more rapid than it can decompose, so you no longer have to worry about dragging out the old plunger. If it does start to smell, troubleshoot by adding more cover material. You can put anything you would put into a normal composting pile into your composting toilet.

Composting Toilets in NYC

As a NYC composting toilet installer we are interested in the composting toilet regulations, or lack of, in Gotham City. Currently we install toilets without seeking permission from the department of buildings. Read pm for an update on the current situation of composting toilets in New York City buildings.

Or don’t read on and know that not much has changed. Composting toilets in NYC fly under the radar. It isn’t against the rules but don’t go around asking for attention either.

Rollie Jones from  the Living Building Challenge Collaborative in NYC has done some good work researching current DOB rules and he just sent me an update. Get ready, it is as convoluted as you would expect from a large city.

As with all toilet stuff, it all comes down to where the stuff goes.  The “end product” as officials call it. No city official wants people to start processing their own sewage waste and for good reason. So the general rule of thumb is that toilets need to be connected to city sewers.

composting toilet
A composting toilet we installed in a brownstone. There were several toilets and the composting collection happened in the cellar.

The Queens Botanical Garden composting toilets for example, were allowed to be installed without any code involvement because the public restrooms were already connected to municipal sewer. The parks depsrtment just installed the Clivus Multrum composting system between the toilets and the sewer, which means nothing ever goes down into the sewer because it gets turned into compost first.

Call it a silly bureaucratic game, but hey it makes everyone happy.

Clivus Multrum (CM) met with the City Building Commissioner regarding the New York Botanical Gardens and was informed that composting toilets were allowed and would be approved on a case by case basis. Again, no clear rules for or against but people are installing them.

Managing the “end product” is a very complicated, multi-department affair. The New York State Department of Environmental Conservation (NYSDEC) is in charge of regulating the end product. They decide if a building gets connected to the sewer system or gets an on site septic system. In the city it is almost always a sewer connection.

The actual handling of the end product is done by the New York City Department of Environmental Protection (NYCDEP). NYC has a combined sewer overflow system (CSO) where our sewers handle both rain water and building sewage. This causes a lot of headache for the NYCDEP because any time there is a good rain the sewers overflow into the rivers and canals.

I live near the Gowanus canal and after each rain you can see all sorts of stuff that people have flushed down their toilet – tampons, condoms, and of course big smelly turds. Nasty.

Polluting the waterways is against the law and basically every time it rains New York City violates the Clean Water Act. The city is being sued by Riverkeeper over this for example.

Then you have the New York City Department of Housing (NYCDOH). They regulate what goes on inside city buildings, including what kind of toilet you have, and thus if you have composting toilets they are responsible for regulating it. But they don’t really. At least I’ve never heard of them saying anything about composting toilets. The NYCDOH does not regulate where the stuff goes once it is flushed down the toilet..

Confused yet?

When the end product isn’t overflowing into the waterways it goes to local treatment plants where it is with other waste products (which may not be bio-compatible) to generate “fertilizer” which may not be actually useful for agricultural applications, but is used anyway. Hey, I’m just passing on this information.

The NYCDEP “treats” sewage and “recycles” as “fertilizer”, which due to the combined input of industry, rainwater and residential/commercial, cannot possibly be adequately measured for contaminants/pollutants. Doesn’t sound wholesome, but again, what do I know.

All this to say that the current system of treating sewage is overwhelmed and insufficient. You wouldn’t normally associate composting toilets with big city living, but I see composting toilets as a great way to reduce this strain on our CSO (also important is reducing rainwater and household water through rain gardens, gray water, green roofs etc).

So, the good news is that composting toilets continue to fly under the radar for the most part, and residential users don’t typically report and have not been asked to report end product usage. There are no “compost toilet police”. And why should there be. What’s the point of reporting that you aren’t using the sewer system.

Not to say we want all sort of novices composting their own waste. If done correctly a composting toilet produces a couple buckets a year of very rich and safe compost for the garden. But if not done correctly you have a big pile of crap festering in your home.

There are ways to regulate composting toilets in big cities. Lots of cities around the world do it. I look forward to when that happens in NYC. Until then we take it upon ourselves to educate our clients and regulate our installations. It’s not ideal but composting toilets are so important for so many reasons that we see no other way.

Removing Lead From New York Gardens

Here are two articles relevant to lead remediation in New York garden soil. Eco Brooklyn gets a lot of calls from clients with a child on the way and a recently purchased house. They intelligently tested the soil in the garden to be sure it is safe for toddlers and to their dismay they often find it has lead in it.

Our solution is usually to remove the top layer of soil, add a protective root barrier and then bring in new soil. We then landscape the garden using salvaged bricks or bluestone to create a patio and native plantings  area free of lead contaminated soil.

Garden Soil Remediation

This garden was barren with lead soil when we got to it. We removed the top layer of soil and brought in a layer of rich compost. We then landscaped with all salvaged materials – bluestone, deck, planter, border. We then planted. The ground was planted with ecological grass which takes a season to grow in. 

Removing the soil is costly however. So recently we have started to look into stay-in-place solutions. The most common one is to simply dilute the existing soil with certain kinds of material.

The best options we have found so far are to load the soil up with rich compost, which is full of iron, manganese, phosphorous and organic matter. These elements reduce the uptake of lead in humans and plants. The iron and manganese bind with the lead and thus make it less accessible. The phosphorous and organic matter increase the soil PH, which reduces the availability of lead uptake.

Some studies have found that doing this actually renders vegetables grown in the contaminated soil safe to eat. Getting the soil to be safe for toddlers is more of a challenge but we are becoming increasingly more confident with this new process. We aren’t completely there yet but we are working towards a solution that involves simply adding specific kinds of compost to the soil. This would reduce the remediation time and cost considerably.

As a New York green contractor and landscaper we feel that remediating NY gardens is a crucial part of making our city safe. There is no point in building a beautiful garden if the soil is toxic. Along with building healthy homes, the garden is a top priority for the safety of our children.

The following two articles are very interesting and worth reading:
Cornell U.

DIY Indoor Vermiculture Composting

If you are a fan of living sustainably you have most likely felt the urge to reduce your waste and begin composting. But living in New York City often leaves residents without much outdoor space. A large part of Green Building in Brooklyn involves meshing innovative techniques with salvaged materials, which is why do-it-yourself composting is a fantastic solution to a massive problem. Eco Brooklyn is a big fan of “Passive House”  philosophy and indoor composting is as energy conscious as it is environmentally friendly. Composting indoors sounds, or rather “smells,” fishy right? In fact if your compost is smelly it’s probably not functioning correctly.

Black Gold
Black Gold

Composting is a simple process by which organic material, mostly complex carbon and nitrogen molecules, are broken down to produce the basic building blocks to support plant like organisms. This compost or “black gold” is essential to reducing the wasted-tons of organic material sent to landfills every time one throws away those banana peels, coffee grounds and filters, or even used paper towels.

With a little human energy and a bit of patience, one can easily turn their two-pound-per-day organic waste into nutrient rich soil for their house plants or garden. The first step is to find a suitable container with at least four cubic feet of volume; basically a trash can with a diameter of 1.5’ and a height of 2’. The container should be salvaged or recycled, must have a lid, and bigger is better if you have the space.


This compostee used an old paint bucket and found a solution to reducing those pesky fruit flies. Her method suggests adding felt to the inside of the aeration holes to prevent any unwanted invaders. I imagine using the activated carbon mesh found at pet stores for cat litter boxes would also do the trick while reducing any unwanted odors.

Keep the Flies Away
Felt on Aeration Holes


Use to Prevent Pests and Odors
Use to Prevent Pests and Odors



Next you will want to find a suitable tray to place underneath the compost bin with some newspaper in case of spillage. The bin should be place in a dark place for best results. Usually under the kitchen sink or on the floor of a pantry will do. Add some soil from anywhere, except near the Gowanus.


Then mix in around four pounds of red worms, depending on how much suitable waste you generally produce, as they will eat about half their weight in material every day. Aeration holes are critical as they allow oxygenation for the worms and the aerobic (need oxygen) bacteria. Foul smelling compost is usually due to “anaerobic” (do not need oxygen) bacteria, so make sure to churn your compost once a week and have at least a dozen ½” size holes in the lid or the top sides of the bucket.


What can you add to your compost bin? Here is a great list of 81 items suitable for composting. Keep in mind that a higher concentration of carbon rich material; “brown stuff”, newspaper, paper towels, wood clippings, will prevent ammonia smells caused by the anaerobic breakdown of nitrogen rich material; “green stuff”, fruit, veggies, coffee grounds.

DIY Composting Bin
“I’m Red, but I produce Black Gold”

Composting generally takes a few weeks, but this wait is very rewarding. It is probably best two have at least two bins as one will get full after a couple weeks and it will need time to mature, which is a great time to start your second compost bin. Also make sure to add “brown” material with your “green” stuff and sometimes a little water if it is too dry or newspaper if it is too wet. Then churn, churn, churn, because there is always a season for composting.

Too much compost? Donate your extras to a local farm or farmers market. The NYC Green Markets are also happy to take your clippings, and “green” waste for composting.

-Anthony Rivale