Extensive reclamation technologies, assets for the development of water reuse in the Mediterranean

In the Mediterranean, the main water reuse application is and will long remain irrigation. Irrigation of public parks, landscape, golf courses, market gardening and orchards is expected to develop rapidly. Such uses require the microbial decontamination of reclaimed wastewater. Extensive reclamation technologies are well adapted to the Mediterranean context for their easy and cost effective O&M; however their ability to reliably meet health related standards have been questioned. The paper reviews the main factors of variations in the bacterial abatement provided by extensive treatment techniques - stabilisation reservoirs, ponds and infiltration percolation. Thanks to advances in the knowledge and modelling of disinfection mechanisms, the predictability of microbial decontamination by extensive technologies is being significantly improved; the development of better design tools leading to reliable treatments is foreseen. However, due to limitations in the microbial removal, extensive techniques cannot meet highly conservative requirements. Extensive techniques will play an important part in the development of water reuse and fresh water savings in the Mediterranean as far as water quality standards only aim at limiting health risks to an acceptable level.