The river of Tigris having tributaries such as the streams of Zap, Botan, Garzan, Batman, Bitlis, Hezil, Dingi and Habur originates from a locality close to lake Hazar to the Southeast of the province of Elazig. The river Tigris is prone to considerable level of physical pollution emaneting from such water insoluble materials as silt, sand and alien solid particles. These inflows have considerably changed the colour, smell and taste of the waters of the river. This pollution continues in spite of the fact that the Etibank Copper Enterprise has been “downsized” to a point where it employs only 50 workers at present.

In a basin where intensive farming is not practised except for a few fertile plains yet immune from industrialisation, water pollution is not at alarming levels. Yet it is certain that environmental problems will be tangible with the advance of GAP.

Water pollution can be described as the emergence of adverse changes in the chemical, physical and bacteriologic characteristics of water. In short, water pollution is the degradation of water quality to a degree that it is no more usable for any purpose in terms of public health and fishing.

Water pollutants can be considered in nine major categories:

1. Wastes that consume (require) oxygen
2. Micro-organisms which cause diseases
3. Nutrients which feed plants
4. Synthetic organic composites
5. Oil derivatives and grease
6. Inorganic composites
7. Suspending solid particles-sediments
8. Radioactive materials
9. Changes in heat.

It is generally agreed that water pollutants can be grouped under four headings. These are :

1. Domestic waste
2. Industrial wastes
3. Wastes from agricultural activities
4. Other wastes.

Environmental problems generated by these factors manifest themselves in several ways.

The following were found in the waters of the Tigris as it flows into and out of the township of Maden: Dissolved oxygen (7.7 mg/lt); chemical oxygen (2.1-3.6); and bio-chemical oxygen (1.5-1.9).

There are quite few researches on heavy metal (Cu, Ni, Zn, Co, etc.) pollution in the waters of the Tigris. Samples of water, sediments (silt, sand, etc.), fish, soil and cereals from or around the river have been analysed. Since the sulphur and hydroxides of these samples do not dissolve in water, they indicate values quite below 1 mg/1t (ppm). But there is significant amount of copper and zinc in sediment samples. The concentrations of copper, zinc and other heavy metals are at higher levels then those found in other scientific surveys.

The problems of drinking and waste water which are so important in terms of public health are not resolved yet in the whole basin. The GAP Administration is waging efforts to solve these problems with separated projects pertaining to individual province and district centres.

1. Drinking water is supplied from three caisson and seven deep wells around the stream of Batman.
2. Wastewater: Batman is one of the provinces which rapidly urbanises and witnesses the growth of squatter settlements. Except for some sanitation facilities which the municipality has introduced to some neighborhoods, wastewater is discharged either to septic thanks or to nearby brooks. There is no treatment. Work on the rehabilitation of the Iluh stream which passes through the town and its sewage connections is ongoing. The treatment facility of the oil refinery was phased in November 1993.

Diyarbakır (Central Province)

1. Drinking water : The springs around Gozeli village were supplemented with 20 deep wells near Serapgozu in 1989. Besides, the DSI deep wells near Serapgozu in 1989. Besides, the DSI deep wells and the waters of Anzele, Ickale and Alipinar were connected to the urban water supply system. The use of the waters of the settled areas leads to the pollution of drinking water resources. A project for withdrawing water from the Tigris and trating it is presently under implementation.
2. Wastewater: The sewage system is almost completed. However, at certain points there are dicharges to the Tigris river without any treatment. Treatment facilities is about to be completed with aid from the German Government.

1. Drinking water: The drinking water need of the central province is met by the spring of Aynsebab and the deep wells bored in the Kiziltepe plain, Esenli and Sultankoy. There is a drinking water project.
2. Wastewater: Individual sewage systems introduced in the past are being used through there is yet no planned sewage system for the whole town. Septic tanks are in use in Istasyon and Yenisehir neighborhoods of the town. In general, waste water is discharged to nearby streams at ten different points. There is sewage project including a treatment facility.

1. Drinking water: Waters of Sinsirgi, Musile and Toptepe are suppilied for domestic use thorough five main storage facilities.
2. Wastewater: There is no advanced sewage system. Discharge is made to the streams of Serisevkuve and Geryakumberi. Septic tanks are widely used. There is a project with a treatment system.

1. Drinking water: It is supplied by the Hesko spring and five caisson wells around the Botan stream. Water is supplied by eight storage facilities after chlorinating. The disinfectation problem remains to be solved. There is a project at hand to bring radical solution to drinking water problem.
2. Wastewater: There is a sanitary sewage system and wastewater is discharged to Botan Stream via Gokcebag brook. Works in relation to treatment have not been completed yet. There are frequent clogging in the sewage system because of animal husbandry activities. There is also a pollution problem which assumes serious dimensions. There is a project for a improved swage system.

• Drinking water supply is a problem for all GAP provinces. The drinking water projects of province and district centres have been prepared by the GAP Administration. There is an absolute need for disinfecting until the completion of relevant projects.
• Sewage and wastewater problems are yet to be solved in all province and district centres of the Region. Relevant projects are ready at hand. Direct discharge to the Tigris and its tributaries is to be abandoned immediately. The Ergani Copper Mining Enterprise should be closed down within one year unless it complies with the specifications of the Environmental Impact Assessment.
• The treatment facility in Batman Which was phased in November 1993 should be brought under control to prevent the confluence of such extremely harmful matters as hydrazine and aromatics composites.
• There must be no permission for the establishment of facilities which may pollute the lakes, reservoirs and dams existing in the region.
• Measures against erosion must be taken in order to prevent soil losses and sedimentation in dam lakes.
• Measures must be taken against pollution and the accumulation of pesticides in dam lakes. There must be a controlled use of fertilisers in formlands around lakes and other water reservoirs. In particular, excessive use of fertilisers must be avoided.