Gaza's power woes have exacerbated the situation. When power is limited, pumping sewage away from homes takes priority, leaving little left over for treatment, Monther Shoblak, head of the Gaza Coastal Municipalities Water Utility, told IRIN.
Why the problem?
During the years before the Oslo Accords of the 1990s, Israel built a few treatment lagoons and plants in the Gaza Strip, though these plants proved to be insufficient as they were smaller than needed, according to the Palestinian Water Authority (PWA).
In 1967 the population of Gaza was 380,000 though now it is nearly 1.5 million, according to the Palestinian Central Bureau of Statistics. Also, over the years more households were connected to the sewage network.
Development projects to improve the capabilities of the sewage and treatment systems drawn up in the 1990s were hampered by the outbreak of violence in September 2000 and a deteriorating security situation.
In 2005 projects which had been slowed down or put on hold were looked at again, but faced problems following the Hamas election victory in 2006 and the subsequent international boycott of the Palestinian Authority.
Also, the PWA had trouble finding private-sector bidders for tenders it issued due to the security situation.
Hamas's takeover of the enclave last year was met with an Israeli embargo, limiting imports to mostly food and medicines. This has affected the ability of aid groups, including the UN, the ICRC and CARE International, to import equipment like pipes in sufficient quantities on a regular basis.
A US project to improve the plant which serves Gaza City was completed about 10 years ago and the new design was meant to handle some 32,000 cubic meters of sewage, though on the first day of operation it was receiving some 35,000 cubic metres, a number which has since gone up.
Overloaded treatment plants
There are three sewage treatment plants in Gaza: one in Beit Lahiya in the north, one near Gaza City, and one near Rafah in the south, which is only a primary treatment lagoon and incapable of treating most of the sewage it receives. In Khan Younis people still use septic tanks.
The overload on the Beit Lahiya plant led to the creation of a "great lake" of effluent which occupies some 30 hectares and holds some two to three million cubic meters of waste water, which UN and non-governmental organization projects are currently working to slowly drain.
In 2006 a smaller lake, which was used by the water utilities to hold sewage and take pressure off the "great lake," collapsed, killing five people in a torrent of filth.
Halted plans
Plans have been drawn up either to build new plants or improve existing ones. Donors have been found in theory to finance most of the work, although those involved in the projects say they are waiting for the funds to fully materialize.
The plans for Beit Lahiya are in two parts. First, the "great lake" must be emptied and the water re-treated, but this is being hampered by import restrictions. The second part involves the construction of a new treatment plant.
Work on the other plants are currently halted or moving at a snail's pace.
Experts said that in the best case scenario, which would include an immediate about-face on the political front, it would take at least 15 years to have plants up and running which fully treat the Strip's waste water, and many more for a full-fledged hi-tech system.
In the medium and short term, the goal is to continue to drain the Beit Lahiya basins and work to at least partially treat all waste water -- though this too depends on the borders opening up and full donor cooperation, along with the willingness of companies to bid on tenders.
Concern has also been raised that if the borders remain effectively shut, and importing spare parts remains restricted, the treatment plants will be capable of handling even less waste.
In the immediate term experts insist that the treatment plants have as much power and fuel as needed to be able to at least function at their current maximum capacities, and all equipment required should be allowed into the enclave.
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