“The geotechnical team has collated data from soil borings conducted not only for the prior project but from other construction projects across the Delta, including design documents for roads, bridges and levee improvements. Based on this data, there is a reasonable understanding of the depth of the competent soils. While there is still some information that needs to be obtained, it appears that the tunnel would not be constructed in peat soils.
Additional geotechnical information would be collected prior to the completion of design. If peat soils occurred at depths considered for the tunnel, the design would be modified to lower the tunnel to competent soils below the peat soils.”