Cathodic Protection Systems and Effects on Fisheries Near Reclamation
* Are cathodic protection systems at Reclamation facilities safe or detrimental to the local fishery and do they alter fish behavior?
Need and Benefit
Several Endangered Species Act (ESA)-listed fish species utilize waters near cathodically protected systems (e.g., juvenile salmonids that migrate near Reclamation's Columbia River pumping plant intake structure located upstream of McNary Dam in Lake Wallula). Reclamation cathodically protected this pumping plant late in 2007. Reclamation has very little knowledge of possible fishery issues related to cathodic protection. Reclamation and National Oceanic and Atmospheric Administration (NOAA) Fisheries are uncertain in determining if there are any potential impacts to listed salmonids during their Section 7 consultation of the ESA that may or may not result from the cathodically protected pumping plant intake structure and fish screens. Endangered Species Act listed salmonids that must pass McNary Dam and migrate through Lake Wallula are:
* Snake River Sockeye Salmon (endangered, 56 Federal Register [FR] 58619)
* Snake River Spring/Summer and Fall Chinook Salmon (threatened, 57 FR 14653)
* Upper Columbia River Spring Chinook Salmon (endangered, 64 Fr 14308)
* Snake River Steelhead (threatened, 62 FR 43950)
* Upper Columbia River Steelhead (endangered, 62 FR 43949)
* Mid-Columbia River Steelhead (threatened, 64 FR 14517)
* Bull Trout (threatened, 63 FR 31647)
All of these listed salmonids may not be affected; however, potential contact with the device or anodes may have adverse effects.
This is not a localized issue, but rather one that has the potential to affect all such underwater structures both for Reclamation and non-Reclamation. Cathodic protection systems on existing structures are adjusted to maintain corrosion protection. The possible increase in applied current to maintain the corrosion protection could potentially have adverse effects on fish species. Therefore, this is not only an issue for new systems but also for existing systems. At this time, a determination of any potential adverse effects or no effect has not been made resulting from cathodic protection. To facilitate this determination, it is necessary to examine existing cathodically protected structures--both Reclamation and non-Reclamation--in order to determine guidelines for current and future cathodic protection systems.
Cathodic protection is the practice of using electrochemical reactions to prevent the corrosion of steel structures and is a typical component of underwater metal structures as well as underground storage tanks. Cathodic protection systems are needed in order to extend the service life of existing and new water conveyance structures. These structures include pumping plants, fish screens, temperature control devices, penstocks, trashracks, and gates. The size of the structure and amount of surface area of the steel to be cathodically protected will determine the amount of current required to be applied. Many of these structures are well over 10 years old and are in need of cathodic protection to extend their service life. Replacement and repair of these structures is expensive both in materials, labor, and service down-time. However, possible adverse affects of cathodic protection systems to aquatic species has not been researched.
The benefit of researching the relationship of cathodic protection systems to the continued existence of fish communities (e.g., ESA fish) will allow Reclamation to protect its structures from corrosion while still preserving listed fish species. The research and resultant guidelines will benefit Reclamation structures as well as structures owned or operated by non-Reclamation constituents.
Contact the Principal Investigator for information about these documents.