Jared Blumenfeld of the EPA says Kettleman City is vulnerable because of the dump and the pesticides used in nearby farming fields. He says his agency wants to investigate whether the town's birth defects can be linked to those factors.
The Kings County Board of Supervisors recently approved expanding the 1,600-acre waste site in the San Joaquin Valley. The proposal still needs state and federal approval.
Residents filed a lawsuit against the board and say they want an investigation into the birth defects and infant deaths.