When Jewish National Fund forester Gilad Mastai made his usual rounds through the Ben Shemen Forest on Wednesday, he discovered to his horror that someone had dumped over 30 tons of construction waste in the forest. "They dumped the trash near the parking lots, where there is easy access for vehicles," Mastai told The Jerusalem Post by phone Wednesday. Unfortunately, this was not an isolated incident, according to Mastai. "This is a phenomenon of cold days. Two weeks ago, the same thing happened," he said, explaining that construction companies take advantage of the cold and stormy weather to sneak in and dispose of tons of construction material. Over 150 tons of trash have been discovered in the area, the JNF said. The waste from building sites is not only ruining the forests, but also costing the taxpayer money. Mastai said he had to rent a truck each time to cart the trash out of the forest to a proper dumping site, and pay the dumping fees as well. "The whole thing costs me about NIS 1,000 each time. But I don't know when I will be able to remove this latest dumping, since I've run out of money in my budget," he told the Post. Mastai said both the police and the Environmental Protection Ministry were involved in the case and that "we have some idea who is doing it." "What many people don't realize is that it may be the construction company renovating their house that could be dumping illegally in the forest," he added.