The Gaza Strip is a land area located along the Mediterranean Sea Southwest of Palestine and north of Egypt. The size of the area is ca 365 km². Due to the tremendous population increase, the water demand increased sharply. The yearly replenishment of the aquifer represents about 60% only. Groundwater is getting more and more salty. The reuse of wastewater could be one of the main alternative options to develop the water resources in the region.

Wastewater reuse in the Mediterranean countries with semiarid climate is essential. This is already practised in many countries in the Mediterranean region. Different quality standards are applied in the region, the standards differ from very low requirements to very strict one.

For the Gaza Strip the following types of reuse are recommended:

For irrigation in agriculture many quality standards are available. The most important parameters are the microbiological standard requirements. To cover these parameters some countries recommend the application of chlorination of the wastewater effluent. This however may lead to the formation of halogenic organic compounds (THM) which mostly are carcinogenic for human beings. Therefore other treatment procedures for desinfection should be applied.

For groundwater recharge a decrease of the nitrogen concentration is necessary due to nitrate limitation in drinking water supply. According to WHO standards for water quality, nitrate concentration in drinking water supply systems shall not exceed 50 mg/l NO₃.

By regarding the different available irrigation methods only these should be applied which distribute the irrigation water beneath the soil subsurface. In this case the evaporation losses are highly reduced, additionally water can be used more efficiently and a higher economical benefit in the long term can be achieved.

In case of agricultural irrigation a secondary (biological) treatment will be recommended, but without nitrification/ denitrification. For the removal of bacteria and other microbial contaminants the membrane activated sludge system is a suitable method. The overall costs (investment and running costs) are similar to the „normal" activated sludge process (with final clarifier).

In case of infiltration in the underground a higher effluent quality is necessary (nitrogen removal). According to a water balance of one treatment plant separation of wastewater streams into one portion treated to high quality effluent for infiltration and another portion for storage and irrigation will be recommended.

The calculation of the specific costs of wastewater treatment and reuse has always to include construction and operation costs. If the treated wastewater will be reused for irrigation, wastewater storage, transport to the fields and distribution have to be considered. Basically, investment and running costs have always to be combined.

The feeling of responsibility for the municipality or the functional association is essential for a good operation of a wastewater system. This is created when the decisions are made by the municipality and when the plant is operated by the municipality.

The inhabitants shall pay for wastewater treatment. This is a method to transfer responsibility to the inhabitants and to encourage them to decrease drinking water consumption and wastewater production.