Water Quality Management of Drainage Systems in Western Delta

Abstract

In Egypt water demand is incrcasmg rapidly parallel to the population increase. At the same time. Egypt's share from the Nile water is fixed (55.5 billion m'lyr). There is also limited rainfall in Egypt along the northern coast (0.2 m/yr).

Several strategies were thus planned to utmostly benefit from the available water resources to satisfY the future requirements. Among these strategies is the re-use of the agricultural drainage water in irrigation. Currently, only about 4 billion m3/year are re-used. This quantity will be increased to 7 billion m3/year in the year 2000.

In this research, the re-use of agricultural drainage water is investigated. EI-Omoum drain was chosen to be our case study. It is one of the most important drains west of the Nile Delta of Egypt. It discharges about 6621 m3/day to lake Mariout. This water is then pumped at El-Max pump station to the Mediterranean sea. The study investigates the water quality in EI-Omoum main drain and the impact of re-using drainage water from Shereshra or Truga area.

The study phases thus proceeded by identifYing the quality of the water in EI-Omoum drain. This was achieved by a monitoring program in the period 1994 to 1996. The results of the program were then compared to the national and international standards (law 48/1982 and FAO. respectively). The water quality indices were also calculated generally and for every season for specific purposes. The seasonal monitoring data were introduced to a mathematical model "QUAL2EU". Different scenarios were then suggested for the safe re-use ofEI- Omoum main drain. The statistical results of the data collected are presented in this research. The results indicate that the Sodium was the dominant cation while the Chloride was the dominant anaion. All the parameters increase in the direction of EI-Omoum main drain outfall and this is due to the polluted drainage water which was lifted to the main drain. The results of indices indicate that the Sodium and the Chloride were the most effective parameters for irrigation purposes in the area. The results of the suggested scenarios in the model indicate that the drainage water either !rom Shereshra or Truga area can be re-used for irrigation and the difference of the impact between each of them is insignificant. It is recommended to re-use the drainage water from Shereshra because of its high quantity and good quality.