Yes that would be acceptable. Also, it may be necessary for FERC staff to perform the detailed spillway inspection and focused PFMA separately from their annual dam safety inspection due to spillway flows, gate operations, safety constraints, etc.
At a minimum the PFMA should include the FERC engineer(s), the CDSE, operators, and the personnel that performed the up close inspection of the chute. The licensee could also have their Part 12D Independent Consultant participate, if desired, and any specialty engineering consultants hired to perform the spillway evaluation.
Yes. If safe access cannot be provided for the FERC engineer it would be acceptable to have others with appropriate experience and qualifications necessary to inspect the spillway and provide a report of their findings to FERC. However, we would prefer that the FERC engineer be on-site at a safe vantage point to observe the inspection while it is proceeding. Also, it would be preferable to conduct the focused PFMA immediately following the contractor inspection so that the observations are fresh on the participants’ minds.
Yes, the focused PFMA session should be similar to a regular PFMA.
Executive summary, review of design assumptions, review of construction records, foundation details/records review, visual inspection identifying any areas of concern including key photographs, monitoring data review, PFMs identified, and follow-up actions/recommendations from the inspection.
The need for future inspections will be project specific, but should be a routine part of every Part 12D inspection.
For additional information, you can refer to guidance in the Bureau of Reclamation and the Corps of Engineer’s Best Practices Manual for Risk Management, specifically Chapters VI-1 through VI-3. Also Appendix B, Potential Failure Modes for Spillways, in Reclamation’s Design Standards No. 14, Chapter 3: General Spillway Design Considerations.
As for the level of testing, FERC is not expecting this initial inspection to include any material testing or drilling. If the inspection team concludes that such additional information is needed, it could be performed at a later date. Any drilling or additional destructive testing must be submitted to the FERC for review and comment prior to performing the field investigations.
This should be determined by the team assessing the spillway and coordinated with your Regional Office
Coordinate with your Regional Office on this issue.
A preliminary memo from the forensic team identifies a list of potential contributing factors.