If USACE is performing the sediment testing, then is the $40-70k cost of the umbrella permit cited in the City’s letter assuming that we don’t have to perform any of the sediment testing for our piggy-back permit?

That is correct. The sediment quality approval process under the umbrella permit would take advantage of a testing exemption allowed for in the EPA guidelines that allows for a report to filed referencing the USACE testing results. This exemption report is included in the umbrella permit cost. However, if USACE finds contamination in the main channel near a residential dock, then some testing would be needed.