26 ENVIRONMENT and ENERGY
A limited number of countries in the world have implemented urine separation and collection systems, with the aim of nutrient( nitrogen, phosphorous and potassium) recycle to agriculture.
Changing household practices at this fundamental level may have significant implications for water use and the availability of wastewater for reuse in the long term. A water reuse strategy that is forward thinking over ten to twenty years needs to take these possible changes into account. The economic tipping point for the implementation of alternative household sanitation approaches will dictate the speed of change.
Direct reuse of treated municipal wastewater for potable purposes The direct reuse of treated municipal wastewater for potable purposes is practised at a limited number of locations in the world. The knowledge of municipal wastewater composition and sophisticated treatment technologies has advanced to the point where this can be considered as an option in the spectrum of water supply alternatives. Specific opportunities exist in the coastal communities and cities where treated municipal wastewaters are discharged to the ocean, effectively losing an opportunity for water reuse. The implementation of such direct reuse projects will, however, have to overcome perceptions and risks related to public acceptance, trust in scientific knowledge and engineered systems, trust in water supply authorities, social justice, and fairness. Direct reuse of treated municipal wastewater for potable purposes would only be practical where sophisticated technology, competent operational and management systems, and safeguards are in place to protect the public health.
Treatment of acid mine drainage Acid mine decant or drainage is a potentially important source of water for reuse. This water must be treated to limit current and future environmental damage to water resources, and can be treated for reuse for industrial and even potable water use purposes. Several AMD treatment and reuse projects have now been implemented in South Africa, demonstrating the technical feasibility, financial viability, and stakeholder acceptance of such projects. Challenges remain to address the issues of appropriate and long-term( post mine closure) operation and maintenance of such AMD reuse schemes. AMD treatment and reuse projects could utilise the large storage available in mining workings, do not have to contend with evaporation loss of water, and can deliver reclaimed water in proximity to several large urban areas, such as the Witwatersrand and Mpumalanga Highveld. PA
July June 2017 Volume 23 I I Number 54 www. plumbingafrica. co. za