Army Corps Lowers Voltage on Fish Barrier

A week after on an electric fish-repelling barrier in the Chicago Sanitary and Ship Canal near Romeoville, the U.S. Army Corps of Engineers is dialing it back down.

On Wednesday, the corps reset Barrier IIB to the previous level of 2 volts per inch, 15 hertz, 6.5 milliseconds amid concerns that the higher settings could be causing interference with nearby railroad operating signals and railroad crossing gates.

Earlier this month, the barrier’s settings were increased to 2.3 volts per inch, 30 hertz, 2.5 milliseconds in an effort to better target Asian carp. The barriers were put in place to keep the invasive carp out of the Great Lakes.

Last month, U.S. Army Corps of Engineers spokeswoman Jacqueline Tate told Patch that the higher voltage would repel not just large Asian carp, but also smaller members of the species.

“We figure we needed to increase the parameters to repel all size fish,” Tate said. While extensive monitoring at the site has not shown the presence of any very small Asian carp, the parameters of the barrier were increased as a precaution.

“Initial results from on-site testing conducted by Corps of Engineers personnel, expert consultants and railroad signal technicians seem to indicate the barrier may be contributing to communication and gate malfunctions and could impact the safe operation of multiple trains using this rail line,” the Corps of Engineers said in a statement released Wednesday. “While we pursue solutions to address this issue as quickly as possible, we feel it was prudent to return to the previous settings to remove that unsafe condition.”