A tidal wave of sewage killed a woman's child in Gaza last month.  The failing sewage system, together with shortages of parts and fuel, has created reservoirs of sewage that are now several metres above ground level, besides poisoning orange groves and other farming land.  An Israeli bomb could release 1.5 million tonnes of sewage, that would cover an area populated by about 10 000 people with nowhere else to go.  Oxfam are currently trying to shore up the reservoirs and the sewage works but are hampered by restrictions on imports of materials eg cement.