Repeated failures of sewage treatment plants in the Gaza Strip has caused significant beach pollution in and around Ashkelon and endangered water quality in the Mediterranean Sea, recent testing by Israel’s Environmental Protection Ministry has found.

The agency ordered the tests in the wake of reports of the discharge of raw sewage from the Gaza Strip into the sea. Scientists from the Israel Oceanographic and Limnological Research Institute analyzed satellite photos taken in the last month to follow the concentration and movement in the sea of chlorophyll, the green pigment found in cyanobacteria and the chloroplasts of algae and plants. The presence of chlorophyll indicates algae blooms as a result of the high concentrations of nutrients in raw sewage.

The researchers found very high levels of chlorophyll in some of the photos, stretching from the southern border of the Gaza Strip all the way to the Ashkelon marina in the north.

The sewage in the sea is not a threat to the operation of Ashkelon’s water desalination plant, which is capable of filtering the pollutions, but it could endanger marine plants and animals, as well as lead to the concentrated growth of fecal bacteria. Widespread algal blooms can also increase turbidity in the water, which reduces the amount of sunlight reaching plants in the sea.

In the past several years the state has invested great resources in ending the discharge of raw sewage from Israeli cities into the Mediterranean. Acre and Nahariya were the last Israeli cities that released sewage into the sea; all the sewage from these northern Israeli communities now goes to a treatment plant.

Sewage treatment problems in Gaza also occurred two years ago. This is not the first time high levels of chlorophyll have been found near Ashkelon beaches.

According to reports, including some in international media, Gaza’s sewage treatment plants are affected by frequent electricity blackouts due to a dispute between Hamas and the Palestinian Authority over payment for fuel to power generating plants in the Strip.

The sewage treatment issues pose a serious threat to the health of Gazans. In recent weeks raw sewage has flowed in streets in the territory. In addition, the sewage can contaminate the groundwater that provides most of the Strip’s drinking water.