Hi Mary, I agree with Anacleto comment above, hence Constructed wetlands might be useful as alternative treatment techniques (low capital and operational costs and do not required qualified persons for operation and maintenance) Refereeing to your suggestion, as mentioned in some comments above, clogging of the sand filter will be the main problem, and therefore will required periodically backwashing. To minimize the backwashing frequency, I might suggest to fill the column with gravel at the bottom, coarse sand in the middle and fine sand at the top, once the clogging is occurred, you need to replace only the above layer of the fine sand with, in this way you will reduce the frequency of backwashing I will suggest first, that you need to determine the volume of the generated graywater from the households so may be one of our colleagues in this group can help you by the design of the system. Finally, I would remind you that if discharge from kitchens will be also included in the system, the household keepers must be aware to remove solids, as possible as they can, before start with washing and don’t discharge oil or fat to the gray water collection system Wish you good success Regards Zaid

Published December 13, 2017 11:47 by Zaid Rashdan, Principal environmental consultant at Al Masader Aldualiyah for environment and quality systems