Direct potable reuse – a feasible water management option

Abstract

Direct potable reuse (DPR) can be more economic than indirect potable reuse as no environmental buffer is needed and conveyance and blending of the purified water with other potable sources is basically less expensive. Long-term experience in Windhoek (48 years) shows that treated domestic sewage can be safely and cost-efficiently utilized for potable reclamation (0.72 €/m3). A multiple barrier strategy is employed in order to attain the highest possible safety levels. There are three types of barriers: non-treatment, treatment and operational barriers. In recent years, new DPR schemes have been implemented in South Africa and in the USA, and the major difference between all the new reclamation processes and the Windhoek New Goreangab water reclamation plant lies in the employment of desalination process units. This topic and other issues, such as the use of ozone and biological activated carbon filtration, are addressed. Reclamation process optimization (increase in sustainability) and the attainment of greater public acceptance are the major challenges facing the promotion of DPR, which should become a common and widely used water management option within the next 5–10 years.

Keywords

• direct potable reuse
• multiple barrier approach
• ozone
• reverse osmosis