Tuesday, September 13, 2011

Army Corps To Increase Carp Barrier Voltage This Fall

Sep 9: As the U.S. Army Corps of Engineers continues to pursue all actions needed to contain the Asian carp threat below the Electric Dispersal Barriers in the Chicago Area Waterway System (CAWS), the Agency announced plans to increase the operation of the barriers to slightly higher parameters. The increase will occur this fall. The Corps released an Optimal Operating Parameters Report including the safety tests used to inform the decision to raise the operating parameters, along with two additional reports: the Independent External Peer Review (IEPR) to test for Asian carp environmental DNA (eDNA) and the National Environmental Policy Act (NEPA) Scoping Report for the Great Lakes and Mississippi River Interbasin Study (GLMRIS).
    While extensive research and monitoring indicate that small Asian carp currently are not within the vicinity of the fish barriers, and all field telemetry research indicates the barrier is highly effective, the Corps is taking this conservative approach to operating the barrier out of an abundance of caution. The Efficacy Study Interim Report IIA, one of three updates released by the Corps, assesses the safety and effectiveness of the barrier at these higher operating parameters. The aspect of the report regarding safety summarizes a series of in-water tests on the barrier that include addressing field-strength mapping, sparking potential during barge fleeting and collision, voltage potentials between barges traversing the barriers, personnel in-water shock potential, stray-current corrosion potential, and optimal settings for the parasitic barrier system.
    The testing shows there is no appreciable increase in risk to public safety with an increase of operational parameters from the current settings of 2.0 volts per inch, 15 hertz and 6.5 millisecond pulse to the new settings of 2.3 volts per inch, 30 hertz, and 2.5 millisecond pulse length. However, it also shows that operating barriers IIA and IIB concurrently increases the area of risk for a person in the water and an increased potential for sparking in adjacent fleeting areas. The Corps does not intend to operate barriers IIA and IIB simultaneously.
    Access a lengthy release from the Corps and links to all documents (click here).