The Krayiot Magistrate Court penalized Haifa Chemicals plant with a NIS 584,000 fine for water pollution.
The plant was charged for streaming waste products into the Mediterranean Sea via the Kishon River in 2002.
The Environment Ministry claimed that was the most serious penalty ever given in Israel for such a violation.
Man, Nature, and Justice foundation told Army Radio they believed the violators should have been handed a prison sentence. "We hope the fine will deter other plants," they added.