What are Vulnerability Assessments?

 


Hydropower facility in the CRB

Vulnerability assessments[1] itemize and inspect all hydropower facility structures and components that come into contact with raw water, and make an informed judgment on the degree to which dreissenid mussels will impair the performance of the structures and components.[2]

A facility assessment process usually requires considerable time for planning and coordination, background research, site visits, evaluation of data and preparation of a report.[3] It is likely that a team approach with two or three people is most effective at carrying out the assessment with at least one person with operational knowledge/experience of the specific facility. The assessment team lead should become familiar with general mussel characteristics and behavior or possibly have a support person familiar with mussels as part of the assessment team.

The specific risks and problems that a particular facility will have with the dreissenids will depend on:

  • The size of the dreissenid population in the area – actual/anticipated.
  • How the raw water gets into the facility.
  • Any processes to treat or transform the water for various facility applications.
  • The routing of all piping branches and location of components and equipment, including materials of construction.
  • The operating envelope of the various water systems (such as maximum and minimum flow rates, frequency of operation, temperature ranges).

[1] U.S. Department of the Interior Bureau of Reclamation, May 2009, Facility Vulnerability Assessment Template, Invasive Quagga and Zebra Mussels. Prepared for Reclamation by: RNT Consulting Inc., 823 County Road 35, Picton, Ontario, Canada K0K 2T0, 26pp.

[2] Prescott, T. Vulnerability Assessment of Zebra and Quagga Mussels on Facilities from Intake to Discharge. RNT Consulting, Inc. (PowerPoint Presentation).

[3] U.S. Department of the Interior Bureau of Reclamation, May 2009, Facility Vulnerability Assessment Template, Invasive Quagga and Zebra Mussels. Prepared for Reclamation by: RNT Consulting Inc., 823 County Road 35, Picton, Ontario, Canada K0K 2T0, 26pp.