Composting Toilets

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GHD's ongoing research and investigation into the application of dry composting toilets and separate collection and use of urine provides for a fundamentally different approach to sanitation.

Benefits of dry composting toilet and urine separating technology

  • Savings of around 20 percent on indoor household water use
  • Reducing the nutrient and salt concentration in domestic wastewater by more than half
  • Use of nutrient resources in human waste to replace chemical fertiliser
  • Lowering the cost of sewage transport and treatment
  • No nett increase in energy use
  • Driving ecologically sustainable development
  • Changing public perception about use of waste as a resource

Challenges with dry desiccating or composting toilets and urine separation

Challenges in toilet system design:

  • Minimising additional building costs and maximising user-acceptability
  • Reliably achieving composting with temperature elevation so as to destroy pathogens
  • The option of desiccation on site with centralised, controlled composting
  • Minimising energy use for ventilation
  • Other 'Green Building' features – integration with other water and energy saving devices or strategies
  • User education and attitude

Challenges in residue collection, transport and resue - logistics of collection; approvals and regulation; demonstrating benefits and savings:

  • Apportioning responsibilities between users, maintenance providers, transporters and body corporate entities and appropriate contractual arrangements
  • Developing appropriate regulations
  • Energy minimisation for transportation
  • Monitoring use of residues and reporting benefits and issues
  • Funding the elements of this sanitation system compared to conventional sewerage

Demonstration project at Maryborough in Victoria

In April 2006, GHD was awarded third round funding by the Victorian Smart Water Fund for the trial installation of six urine-separating composting toilets and two waterless urinals at the new Maryborough Education Centre in Maryborough, Victoria. (This follows on from the report for the Victorian Department of Education and Training.) The Victorian Smart Water Fund is an state government  and Victorian water industry initiative supporting the development of innovative water conservation, water recycling and sustainable biosolids solutions.

GHD provided design advice to the architects, Oaten Stanistreet Architects, and has set up training and monitoring programs for the toilet installation as well as for an agricultural reuse trial using separated urine. The new campus was constructed for the Victorian Department of Education and Training, and comprises primary and secondary facilities for over 1500 students and staff. The installation was completed on time for use when the campus started operating in April 2007. The trial continued through to April 2009, providing two years of operating experience.

Usage of the toilets was lower than anticipated and this limited the information gained on composting performance. The urine reuse trial, however, showed that urine could be applied to growing pasture and crops without detriment and with benefits similar to chemical fertilisers. The toilets were easily kept clean, were free of odour and fly problems during the trial and a majority of users considered them to be acceptable. The project has provided considerable data of use in design of future installations including detailed analyses of urine and compost, data on ventilation and heat transfer for the composters, and some data on crop response and soil analysis from the agricultural trial. User attitude surveys are also included.

The project was funded by up to AUD$170,000 from the Smart Water Fund. This project was also supported by contributions from the various parties involved in the design and management of, and equipment supply for, the project.

The use of dry composting toilets with urine separation as opposed to conventional water-flushed toilets saves water and recovers useful nutrients that can replace manufactured fertiliser for agricultural use, with no more consumption of energy than conventional sanitation.

  • Report: Maryborough Education Centre – Ecological Benefits of Excreta Segregation, Urine-Separating Dry Composting Toilet Demonstration Project Milestone 6 Report, June 2009.

 

Download:

Participants:

Smart Water Fund | http://www.smartwater.com.au/ |
Environment Equipment | http://www.rotaloo.com/ |

GHD participated with these parties in this project and provides links to their websites in recognition of their contribution. These links do not imply endorsement of services or products of these parties.

GHD also acknowledges the contribution of the following organisations on this project: Victorian Department of Education and Early Childhood Development, Oaten Stanistreet Architects and Maryborough Education Centre.

Composting Toilet Demonstration Feasibility Study

This study was a detailed assessment of the application of composting toilets and urine separation to medium density apartments and new subdivisions (proposed 12-apartment complex near Melbourne’s CBD), October 2003. It also reviewed the application of dry sanitation to unsewered urban areas.

  • Report: Composting Toilet Demonstration Feasibility Study, October 2003.

Download: Executive Summary (279KB pdf) and full report: Volume 1, Report (1.5MB pdf); Volume 2, Appendices (2.6MB pdf)

Participants:
Smart Water Fund | http://www.smartwater.com.au/ |
Environment Equipment | http://www.rotaloo.com/ |

GHD participated with these parties in this project and provides links to their websites in recognition of their contribution. These links do not imply endorsement of services or products of these parties.

GHD also acknowledges the contribution of the following organisations on this project: City West Water, CSIRO, Department of Human Services (DHS), Environment Protection Authority (EPA), Melbourne Water Corporation, Monash University and University of NSW, Bensons Property Group and Demaine Partnership.

For further information, contact:

Elise Daniels
Tel: 61 3 8687 8703

Wastewater Treatment

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Because all wastewaters are different, it is necessary to work with a team that can combine comprehensive knowledge with practical experience in the fields of chemistry, biology, hydraulics, mechanical processes/equipment, instrumentation and control, materials handling and plant layout.

GHD can deliver on all the process components that make up a wastewater treatment plant. We have designed and project managed more than 300 wastewater treatment plants (including major municipal facilities processing 500Ml a day and industrial projects).

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