Urine Separation (031-DP-8)
Discussion Paper Summary
Urine separation, which involves the separation of urine from the wastewater stream at its point of generation, is increasingly being recognized as an innovative way of treating wastewater and of practicing resource recovery. By separating urine at the source a significant environmental and economic savings can take place:
- Urine is an alternative source of nitrogen and phosphorus based fertilizers. Currently these fertilizers are created from non-renewable resources such as natural gas, ore and potash deposits.
- The separation of urine benefits wastewater treatment, and has the potential to turn wastewater treatment from an energy consumer into an energy producer.
- Micro-constituents such as hormones and pharmaceuticals can be more easily removed from wastewater using urine separation.
- Removal of urine from wastewater prevents costly removal of nitrogen from traditional wastewater streams, saving money and creating a healthier marine environment.
Urine Separation Technology
Nomix toilet technologies are still in the early stages of development, but these present the best option for capture of urine. Transport of urine to a central location also presents a challenge to the CRD. Options could include truck transport, a dedicated pipe system or use of existing sewers during low flow periods. Once at a central wastewater facility, the urine would be processed to remove nitrogen and phosphorus and the remaining liquid treated along with other wastewater before being discharged. Urine separation has not yet been implemented at full scale at a wastewater facility. Studies in Sweden show that urine-based fertilizers are as effective as commercial fertilizers.
Urine Separation Potential
Urine separation is still at an early stage of development for use in wastewater treatment facilities, but it could be made part of the CRD’s medium to long term planning (year 2030-2065) for wastewater treatment facilities, with new developments in the Core Area including urine separation technology.
Based on a population increase of 86,000 during this time frame, the annual urine-based nitrogen recovery would be approximately 95 tonnes/year in 2065, providing enough nitrogen for 475 hectares of farmland. Part of this benefit would include energy and greenhouse gas savings.
© Image courtesy of Evan Leeson