The Lachish River, which runs from Ashdod to Kiryat Gat, contains up to 39,000 times the permissible amount of coliform, a bacteria found in excrement, according to the water pollution watchdog organization Zalul.
The highest recommended amount of coliform is 200 milligrams per liter. Up to 7.8 million mg/l were found in the Lachish River last week, Moran Diment, head of Zalul's Lachish River project, told The Jerusalem Post on Wednesday. For the past six months, Zalul has been monitoring the Lachish River, she said.
The most recent test, conducted after the Ashdod Municipality had told Zalul the river was clean, indicated that raw sewage is flowing into the river, particularly in the Ashdod area, Diment said.
In the past, industrial waste was not found in the river. This time, Zalul tested only for sewage deposits.
Zalul plans to test the Lachish River's water quality every two to three weeks, Diment said.
"We want the Ashdod Municipality to invest in solutions that will improve the condition of the river," she said, adding that the municipality should find out where the waste is coming from.
The Ashdod Municipality declined to comment.