As more people become aware of adverse impacts to local streams and groundwater, brought about by development, they are considering alternative technologies to reduce those impacts. One alternative gaining interest is the composting toilet to replace conventional flush toilets. However, composting toilets can present a challenge to those charged with approving permits and applying building codes. To unmuddy the waters, we offer some basic information about these cost- and environment-protecting products.
What’s a composting toilet?
Composting toilets are one of many available fixtures and systems that reduce personal water use. These kinds of fixtures reduce the costs of water supply and treatment, and the costs of new construction, while also serving an important role in minimizing potential harms to waters used for drinking, farming, recreation and industry.
Composting toilets use very minimal or no water at all to move waste into a tank where heat and oxygen work with the microbes in the waste to transform it into compost that can be safely used in gardens. These toilets can be self-contained units, or attached to a central collection tank. A variety of models for residential and commercial buildings are now found in private homes and public buildings throughout the country, including places like the Vermont Law School, which was able to reduce water consumption campus-wide at the same time it added a new large multi-use facility - by including composting toilets in the new building.
Where are composting toilets used?
Composting toilets are used to solve tricky wastewater situations like that found in the watershed of Skaneatales Lake, in New York state. There, topography and development patterns led to the use of private privies with a bucket collection system run by the town. This system was contributing to water quality issues in the lake, which was the region’s drinking water source. In a creative response, the town provided composting toilets to the majority of the remaining homes still using the bucket system, removing a major cause for concern about the region’s drinking water.
What assurances do we have about composting toilets functioning?
Concerns about the efficiency and possible negative side-effects of composting toilets are alleviated by certification. National standards for composting toilets are established by NSF International, through a public process involving manufacturers, users, and public health agencies. States and cities that have adopted building codes or ordinances allowing composting toilets generally require that NSF-certified toilets be used. For example, Pennsylvania’s code references the NSF certification: “composting toilets shall bear the seal of the NSF indicating testing and approval by that agency under Standard No. 41.”
NSF’s Standard 41 includes six requirements that composting toilets must meet in order to be certified:
· The toilet system can handle the stated capacity for an extended period plus occasional overload.
· The toilet system has no offensive odors.
· The composted output has been demonstrated to meet required bacterial content levels.
· Advertising, literature and labeling are not misleading.
· Products undergoing testing are not accessible to the manufacturer.
· Lab test results are confirmed by parallel testing of toilet systems operating in the field.
By requiring composting toilets to be NSF certified, permitting agencies can rely on objective expertise in reviewing applications that involve composting toilets.
To help local planning and zoning boards assess proposals that include alternative water-saving fixtures and other environmentally-sensitive products, places like Portland, Oregon and Cococino, Arizona have established Advisory Boards to provide expert evaluation and recommendations. Tapping into available expertise during review and approval of project applications reduces the burden on local officials, and ensures that approved projects will have minimal complications.
Do composting toilets mean no on-site septic system?
In most cases, including a composting toilet in a building plan does not mean that a septic system is not necessary. Other water-using products, like showers and sinks, will need to drain their graywater somewhere. The good news is that the necessary septic system can be put to less stress and last longer when it does not also have to deal with waste. Similarly, municipal wastewater treatment systems will be easier and less costly to run when they receive reduced inputs because of composting toilets. Communities operating combined stormwater and sewage systems can consider composting toilets as another way to reduce the frequency of combined sewer overflows and ensure their compliance with state water quality standards.
Why should we support composting toilets in buildings in our community?
Composting toilets offer many overlapping benefits to individuals and communities. They can reduce building costs of new development, reduce stress and costs for local wastewater treatment systems, and alleviate negative impacts to important water resources for fishing, recreation and industrial uses.
Beyond these benefits, incorporation of composting toilets and other water-saving fixtures in new development can provide an important boost to local economies. Small plumbing contractors and retailers offering these options would benefit from increased interest in upgrading existing systems, countering the losses these small businesses endured during the Covid-19 downturn in construction.
Composting toilet technology is rapidly advancing and improving. These are far from the privies and outhouses of old – they are state of the art, efficient and unobtrusive. These products are a great tool for individuals and communities to use to protect the natural resources that are important to them.
Have questions about composting toilets? Give us a holler at info@fairshake-els.org or (412) 664-5546.
