Solutions to Mussel Infestation Issues in Fire Protection and Other Systems at Reclamation Facilities
Project ID: 6002
Principal Investigator: Ron LeBlanc
Research Topic: Invasive Species
Priority Area Assignments: 2012 (Zebra and Quagga Mussels)
Funded Fiscal Years: 2012
Keywords: zebra quagga mussels oxygen membranes fire protection risk assessment
Invasive species are causing an increase in operation and maintenance costs at Bureau of Reclamation (Reclamation) facilities, as structures require periodic cleaning. Significant time and money are spent to keep facilities operating safely. There is a particular issue with fire protection as many facilities use raw water from the penstocks plumbed directly to suppression equipment. This equipment could be subject to fouling, which would render it inoperable.
A compounding problem could exist when cooling water systems are unable to deliver enough water flow such that turbine bearings can overheat. When insufficient cooling is practiced, the fire hazard from overheated equipment increases. The overall risk to facilities due to mollusk fouling is significant.
Many strategies have been investigated to either prevent deposition or facilitate removal of mussels. Chemical and pesticide treatments are effective, but have hazards associated with discharge to the environment and toxicity to other species downstream.
Mussels require at least 2 milligrams per liter (mg/l) of dissolved oxygen to thrive in place attached to a solid surface. Most surface waters that are used by Reclamation have much higher oxygen saturation levels and therefore provide acceptable conditions for attachment and growth. Oxygen scavenging is a potential control strategy and is not currently practiced at Reclamation facilities. It may be a safe protective mechanism from mollusk fouling.
There are three research questions:
1. What are current practices at Reclamation facilities and what is the level of risk associated with them?
2. What are some of the solutions to reducing risk and maintaining effective fire suppression capability?
3. Can degasification prove to be effective and more economical at controlling invasive species than current methods of control and remediation?
Need and Benefit
It is well known that invasive species are spreading in area and density in water bodies throughout the United States. Reclamation facilities in the Colorado River System could be particularly hard hit due to the warmer climate, which is allowing several life cycles per year.
Mussel proliferation in the Southwest is changing the previously established knowledge on growth and ecology. They are thriving in conditions previously thought to be unfavorable and are spreading more quickly than they were in areas such as the Great Lakes region.
Reclamation facilities could soon be experiencing operational difficulties due to mussel fouling of dams and hydroelectric equipment. The difficulties include fouling of (1) cooling pipes for bearings, (2) water-based fire suppression systems, and (3) trash racks at hydroelectric inlets.
The potential benefits from control of infestations include risk reduction in terms of fire safety, maintenance savings on major components such as bearings, and preservation of revenue that would be lost as energy (and therefore electricity produced) from fouling of inlets.
Draft and final reports with results of risk assessment, appraisal level estimates of risk mitigation, experimental results and recommendations for invasive species control.
Possible publication in journals.
This information was last updated on October 30, 2014
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