Even today, however, human and mechanical failures, alone or in combination, occasionally lower barriers to deflect and contaminate water supplies that otherwise would have a long history of security. This is why water safety remains the most essential and undisputed responsibility of water utilities, from their engineers and general staff down to the most recently hired worker. Five categories of parasitic organisms infectious to humans are found in water: bacteria, protozoa. , worms, viruses and fungi. Some of them complete their life cycle by passing through an intermediate aquatic host. Others are simply transported by water from human to human, posing a considerable risk to themselves. Examples of organisms that spread diseases through water via the fecal-oral route are cholera and typhoid bacteria. Cholera and typhoid fever were transported and disseminated by early municipal water supply and sanitation systems during the 19th century.2.4 Waste management2.5 Health security and environmental impactAccording to Fatta et al. (2005), “human health and environmental concerns constitute the most important constraints in the reuse of [treated] wastewater”. It is common for sewage treatment plants in Arab countries to not operate satisfactorily and, in most cases, discharges of treated wastewater exceed legal and/or hygienically acceptable maximums. This is attributed to the lack of properly trained personnel with the necessary technical skills to operate these factories, as well as the lack of adequate budget for the maintenance and operation of the factories. Irrigation with insufficiently treated wastewater poses serious risks to public health, as wastewater is a major problem. source of excreted pathogens - bacteria, viruses, protozoa, ...... middle of paper ...... each year, representing 29% of the total industrial water demand in 2009. In the municipal sector, increase secondary wastewater treatment and reuse has delivered significant cost and energy savings for six inland cities, while an estimated 26% of urban water needs could be met by treated wastewater. Therefore, industrial and domestic water reuse has the potential to significantly reduce water withdrawals, conserve water from non-renewable aquifers, and reduce reliance on desalination, which relies primarily on non-renewable natural gas . Planned investments in desalination projects could also be postponed by prioritizing investments in sewerage and water distribution networks that would ensure more efficient water recovery and reuse while simultaneously conserving water resources. non-renewable groundwater and natural gas and avoiding potentially unnecessary desalination blockage.