(March 13, 2019) As part of efforts to improve operations of the Electric Dispersal Barriers in the Chicago Sanitary and Ship Canal, the U.S. Army Corps of Engineers conducted an assessment of Barrier II’s equipment in January 2017. (The electric barriers are operated to deter the inter-basin establishment of Asian carp and other fish via the CSSC by maintaining an electric field in the water.)
Visual inspection of the electrodes at the barrier found a material loss of approximately 2 square inches across the electrodes per year. What had been a 5-inch square billet at Barrier IIA became a 3-inch diameter round billet after roughly eight years of operation.
USACE used $3.5 million in GLRI funding to replace the electrodes. This work was completed in February 2019.
The initial life expectancy of the electrodes was approximately 25 years, but the rate of corrosion was higher than expected. The increased rate is most likely due to the operation of the system at higher settings than the original design. USACE increased operational settings at Barrier IIA twice since activation (in 2009 and 2011) to address increased risk.
The conductive material at Barrier IIA’s narrow electrodes was significantly compromised. The rate of corrosion was expected to accelerate over time as the material becomes more permeable. As a result, USACE requested and received $3.5 million in GLRI funding to replace the narrow array electrodes at Barrier IIA. The contract was awarded in December 2017, and work was completed in April 2018.
Due to savings realized by acquiring materials directly from the Defense Logistics Agency instead of the contractor, funds were available to also replace electrodes at Barrier IIB. This work was completed in February 2019. IIB’s electrodes were nearly as corroded as those replaced at Barrier IIA the previous year.
USACE also received $1.5 milliion in GLRI funds to convert the Demonstration Barrier’s cable electrodes to the steel billets used in Barrier II. This work, completed in January 2019, is part of the overall effort to upgrade the Demonstration Barrier to permanent status as directed by the Water Resources Development Act of 2007.