Domestic wastewater originates primarily from residential, commercial, institutional and public buildings. Once domestic wastewater is discharged into the sewer, dilution and/or contamination may occur by added industrial wastewater and storm water. These together determine the final hydraulic and waste load at the treatment facilities.
The amount of domestic wastewater produced per capita per day is usually 80-90% of water consumption. The quantity of domestic wastewater produced in the Hebron District was calculated based on an assumption that sewage is 80% of the average water consumption, multiplied by the estimated population. The total annual produced wastewater is approximately 1.86 mcm.
As is the case in the rest of the West Bank districts, water quality and quantity data for the Hebron District is scarce. Few studies and measurements concerning the quality and quantity of wastewater have been conducted. In a recent study, carried out in August 1994 for the Palestinian Economic Council for Development and Reconstruction (PECDAR), wastewater samples were taken from different locations in the West Bank and Gaza Strip, including the Hebron District. These samples were analyzed at the Islamic University in Gaza City. The results of this study revealed the characteristics of raw domestic wastewater in Hebron District (Table 8.1).
| Parameter | pH | BOD5 | COD | TSS | Cl- | PO32- | P | NO3 - | NO3-N | Na+
|
|---|---|---|---|---|---|---|---|---|---|---|
| Value | 6.0 | 520 | 2736 | 1794 | 3540 | 133.5 | 413.8 | 33.4 | 7.6 | 839
|
| * All values, except pH, are in mg/l | ||||||||||
Industrial wastewater is the water produced by different types of industries which often contains heavy metals or organic loads and can have a negative impact on the environment. The major industries in Hebron City are: leather, tanning, shoe making, quarrying, and stone cutting. The most hazardous industrial waste comes from the tanning industry where its discharged wastewater contains Chromium ions. Industrial waste water is discharged into the sewer system or disposed into the wadis and open spaces without any preliminary treatment.
Wastewater disposal constitutes a major threat to health human and the environment in the Hebron District. The wastewater sector has been neglected in the district, and as a result, sewage is managed poorly. Only 55% of the population are connected to the sewer system located in Hebron City, the rest of the population disposes of sanitary waste in cesspits and open drains. Cesspits are used by all residents in the rural areas. Open drain system is used by some residents in the refugee camps.
Cesspits are a common alternative for wastewater disposal in the absence of sewage system. Cesspits are usually designed to serve a single household or a multiple apartment building. The volume of the cesspit depends on the availability of land space and the economic status of the owners. They range from 5 to 25 cubic meter. Cesspits are usually emptied by vacuum tankers owned and operated by either the municipalities, UNRWA, or the private sector. Contents are disposed of at any available location, in many cases, in the streets and wadis. Sewage is apparently disposed of without consideration to the natural habitat, soil fertility, groundwater, or built-up areas.
Open drains are most common in refugee camps, which are not served by a sewer system. Open drains are used at both of the district refugee camps, Al-Fawwar and Al-'Aroub. Domestic wastewater and storm water is collected in the open drains, it then flows outside the camp boundaries onto unattended land without any treatment. Overflow of the drains is predictable, especially during the winter time.
The present wastewater network in the Hebron District serves only 50% of the Hebron City. The present network is very old and has many problems, such as: accumulation of solid waste from stone cutting factories, workshops, and slaughterhouses causes regular clogging and flooding of the sewer system; and the absence of a storm water drainage system causes overload of the network, which results in blockage and flooding thereby leaving stagnant pools at the streets. Wastewater from the network is transferred through a main pipeline to the south of the city near wadi As-Samn, where the pumping station is installed. It should be pumped to the sedimentation ponds located to the east of the city, but for several reasons, the pumping station is non-functioning. The wastewater flows through wadi As-Samn to the south-west, impacting the crops, fruits and vegetables which are freely planted and irrigated along the sides of the wadi. Infact, the current situation encourged several several farmers to utilize the flowing sewage in irrigating their crops along both sides of the vally. Livestock also use the flowing wastewater for drinking.
The main objective of wastewater treatment is to protect the environment from:
This is done in order to:
In the Hebron District, no treatment plant is available. Algal ponds were constructed and a pump station was installed in 1988. As mentioned above, the pumping station was clogged after 2 months of operation, and from that time, the pumping station and the ponds have not been used.
Simple primary treatment is performed in some of the stone cutting factories in the district by collecting the generated wastewater in adjacent ponds to allow separation of particles by natural settling. The treated water is then collected from the top of the pond for reuse in the stone cutting process.
The major environmental-related problems found during the field survey in the district are as follows.
The challenge of an adequate wastewater collection and disposal system requires immediate attention from the authorities and official institutions. Public awareness and education about the need to properly manage wastewater must be increased, especially among farmers and consumers. The potential danger of improper sewage disposal to human health and welfare should be stressed. Authorities must enforce regulations that require proper wastewater disposal by individuals, the commercial sector and industrial facilities, to prevent pollution.
To improve the existing situation the following recommendations are presented:
