Composting or dry sanitation provide waterless toilet options. In northern Europe such alternatives are frequently used in cabins and for homes in rural areas. Composting toilets are also widely used in dry areas and poor countries. Such kind of toilets can be designed with or without urine diversion (see also UDDT and urine diversion components). Investigations have shown that in Scandinavia, composting toilets make it difficult to achieve temperatures above 40°C in the composting compartment and it is questionable whether the material is hygienised unless very long resting periods are used before emptying (two years at ambient temperature in the Scandinavian climate according to WHO (2006)). International research shows that dry sanitation may give an equal or higher reduction of pathogens and a high reduction in risk of exposure (STENSTRØM 2002) (see also pathogens and contaminants). Hence, dry sanitation or composting toilets are not inferior to other types of sanitation provided the right measures are taken in operation and handling. One of the highest potential health risks occur when the toilet needs to be emptied. This can be counteracted if the toilet is designed with removable compartments or if professionals perform the emptying. In order to assure a proper hygienised material, secondary composting should be performed (see also co-composting small scale) (to read more about it, see also DEL PORTO & STEINFELD (1998) Professional collection and secondary composting of waste from composting toilets has been tried in Norway. A local farmer collected the toilet waste and treated this in a composting reactor (in vessel) that renders a hygienised soil-like end product.
This lecture describes the concept of professional collection and treatment in a small rural community and the technology involved. Partially composted excreta was mixed with food waste and bark and sanitised in a bioreactor (see also biogas settlers). The insulated reactor was fitted with a vacuum pump to collect leachate, which was recycled to the compost. The results suggest that secondary composting can produce a safe soil amendment in about two months – in contrast to the generally recommended six months – provided the system is properly managed.
For an overview on this topic, see also hardware and software tools for treating wastewater.
The Composting Toilet System Book
The Composting Toilet System Book is an impressive, comprehensive, reader friendly, and practical guide to choosing, planning and maintaining composting toilet systems for those seeking an alternative to traditional sewer and septic tank systems. It explains the technologies, sources, applications, greywater issues, and regulations relevant to a composting toilet system for the home, whether manufactured or site-built.
DEL PORTO, D. STEINFELD, C. (1999): The Composting Toilet System Book. A Practicle Guide to Choosing, Planning and Maintaining Composting Toilet Systems, an Alternative to Sewer and Septic Systems. Concord: Center for Ecological Pollution Prevention (CEPP)Hytteklosetter-Alternative avløpsløsninger for hytter og spredt bebyggelse, med hovedvekt på miljøkonsekvenser
Reduction Efficiency of Index Pathogens in Dry Sanitation Compared with Traditional and Alternative Wastewater Treatment Systems
Bad water, sanitation and personal hygiene combinedglobally considered as the second major threats to human health. Poor water supply, sanitation, and personal hygiene accounted for 2.6 million deaths and 93 million DALYs in 1990. These were considered the top 2 of risk factor groups for the total global burden of disease. It is therefore of importance to define the efficiency of different treatment and exposure barriers to safeguard against disease transmission.
STENSTRØM, T.A. ECOSANRES (2002): Reduction Efficiency of Index Pathogens in Dry Sanitation Compared with Traditional and Alternative Wastewater Treatment Systems. Solna, Sweden: EcoSanRes URL [Accessed: 28.11.2012]Guidelines for the safe use of wastewater excreta and greywater. Volume I. Policy and Regulatory Aspects
Volume I of the Guidelines for the Safe Use of Wastewater, Excreta and Greywater focuses on policy, regulation and institutional arrangements. Accordingly, its intended readership is made up of policy-makers and those with regulatory responsibilities. It provides guidance on policy formulation, harmonisation and mainstreaming, on regulatory mechanisms and on establishing institutional links between the various interested sectors and parties. It also presents a synthesis of the key issues from Volumes II, III, and IV and the index for all four volumes as well as a glossary of terms used in all four volumes is presented in Annex 1.
WHO (2006): Guidelines for the safe use of wastewater excreta and greywater. Volume I. Policy and Regulatory Aspects. Geneva: World Health Organisation URL [Accessed: 10.04.2019]Guidelines for the safe use of wastewater excreta and greywater. Volume II. Wastewater Use in Agriculture
Volume II of the Guidelines for the safe use of wastewater, excreta and greywater provides information on the assessment and management of risks associated with microbial hazards and toxic chemicals. It explains requirements to promote the safe use of wastewater in agriculture, including minimum procedures and specific health-based targets, and how those requirements are intended to be used. It also describes the approaches used in deriving the guidelines, including health-based targets, and includes a substantive revision of approaches to ensuring microbial safety.
WHO (2006): Guidelines for the safe use of wastewater excreta and greywater. Volume II. Wastewater Use in Agriculture. Geneva: World Health Organisation URL [Accessed: 05.06.2019] PDFGuidelines for the safe use of wastewater excreta and greywater. Volume III. Wastewater and Excreta Use in Aquaculture
Volume III of the Guidelines for the Safe Use of Wastewater, Excreta and Greywater deals with wastewater and excreta use in aquaculture and describes the present state of knowledge regarding the impact of wastewater-fed aquaculture on the health of producers, product consumers and local communities. It assesses the associated health risks and provides an integrated preventive management framework.
WHO (2006): Guidelines for the safe use of wastewater excreta and greywater. Volume III. Wastewater and Excreta Use in Aquaculture. Geneva: World Health Organisation URL [Accessed: 08.05.2019]Guidelines for the safe use of wastewater excreta and greywater. Volume IV. Excreta and Greywater Use in Agriculture
Volume IV of the Guidelines for the Safe Use of Wastewater, Excreta and Greywater recognizes the reuse potential of wastewater and excreta (including urine) in agriculture and describes the present state of knowledge as regards potential health risks associated with the reuse as well as measures to manage these health risks following a multi-barrier approach.
WHO (2006): Guidelines for the safe use of wastewater excreta and greywater. Volume IV. Excreta and Greywater Use in Agriculture. Geneva: World Health Organisation (WHO) URL [Accessed: 09.05.2019] PDF