Egypt is an arid country which depends almost entirely on the River Nile for its water supply. It is estimated that the Nile provides 95 percent of the country's fresh renewable water supply. Despite the importance of water, the Nile water distribution network is subject to contamination by point and non point sources of pollution in addition to disposed wastes.

During the last decade considerable attention has been given to the monitoring of water quality and the establishment of monitoring programs. Various institutions belonging to several ministries have conducted monitoring activities on water quality, each according to their own mandate, requirements, and priorities.  Several of these institutions are situated within the Ministry of Water Resources and Irrigation (MWRI) and specifically in the National Water Research Center (NWRC), while others follow other ministries.

The NWRC's research institutes conduct periodical physical, chemical and biological analyses on samples taken from the Nile and its water courses to identify its suitability for purposes of irrigation, human or animal uses.

NWQM Program is formulated and implemented to provide decision makers with information about the present status of surface and groundwater and to predict changes to the water quality that have an influence on water management planning and policies. NWQM program consists of 232 surface locations (Lake Nasser, Nile River, Nile branches, canals and drains) from which 69 locations are for the Nile River and its two branches and 203 groundwater wells involving some of 32 water quality parameters varying from physical, oxygen budget, nutrients, major ions, metals, biocides and microbiological variables.

Pollution along the Rosetta river branch of the Nile Delta mainly originates from agricultural drainage canals. Three drains (El-Moheet, Sabal and Tala) are monitored with different water quality variables measured on a monthly basis through NWQM program. Along this branch, there are four locations where samples are collected on a frequently basis and their water quality parameters are measured and detected. These locations are NL42 at km 1077 from Aswan High Dam (upstream Menofiya drinking water supply intake), NL44 at km 1123 from Aswan High Dam (upstream Disuq drinking water supply intake) and NL46 at km 1156.5 from Aswan High Dam (upstream Edfina barrage). A complementary study is considered by the Ministry of Water Resources and Irrigation (MWRI) to assess the water quality of Rosetta branch covering the distances between the monitoring sites of the National Water Quality Monitoring Program NWQM. The total number of locations involved in the survey is twenty four sites with emphasis on locations receiving water from drains outfalls and industrial effluents in the Nile River main course.

Currently, fisheries in Egypt range from the traditional village type ponds to modern governmental and private fisheries. Production of fish in floating cages has been established in the Nile River and its branches because it is a simple technology and does not need additional water which is economically feasible under Egyptian conditions. In both Rosetta and Damietta branches, there are many licensed and unlicensed floating fish cages. There are benefits of such culture including increases in farm productivity and profitability without any net increase in water consumption. However there is much concern about an environmental hazard resultant from the discharged pollutants to water.

This negative impact is based on an assumption that can be summarized as follows:

1.      Toxic substances, that are either naturally present or added to the feed components before, during or after processing, or that are regenerated due to the feed decomposition resultant from its storage, may be detrimental to other organisms including plants and man.

2.      Aquaculture drainage water that may contain residues of hormones, pesticides, herbicides, antibiotics or chemical compounds associated with fish treatments can cause serious problems to the ecosystem and the human health.

3.      Bad operation of the floating fisheries associated with over-stocking of fish in the cages may cause negative impacts on the water quality.

4.      Nutrients in the floating fish cages are primarily derived from feed wastes (fines, dust and feed that is not eaten by fish), excreted and faecal wastes. Usually, such discharged nutrients are in form of NH4. However, during the process of equilibrium, if NH3 exceeds a certain level, it may be toxic to human and other organisms.