100,000 meters cubic meters of acidic water spilled into the Judean Desert's Ashalim River, after the side of a water reservoir was breached.
The reservoir, which is owned by Rotem Fertilizers, covers an area of 4.9-7.4 acres (20-30 dunams).
As a result of the spill, the Dead Sea-Ein Tamar section of Israel's Highway 90 has been closed off for three hours.
Israel's Nature and Parks Authority called on hikers to avoid the Ashalim River and nearby routes until further notice.
The Environmental Protection Ministry is conducting an investigation of Rotem Fertilizer's plant and the reservoir breach, which polluted the Ashalim River and caused severe ecological damage.
Ministry staff and Israel Police collected testimonies, proofs, took samples, and monitored the area.
The Ministry also said it would order all of the company reservoirs in the area to cease operations, and that it will call the company to a hearing and ensure the proper procedures are followed. There may also be a criminal investigation.
The deeper cisterns in the lower parts of the Ashalim River are still filled with acid, which the company must pump out in order to begin the urgent work of rehabilitating the river.
Nature and Parks Authority Southern District Director Gilad Bar told Channel 10, "At the moment, we are focusing on teams that are moving on foot in the riverbeds to sample the water throughout the sections of the stream, so that we can get a sense of the water’s [condition]."