WAC 173-160-457   How are vibrating wire piezometers constructed?  (1) The bore hole containing the vibrating wire piezometers shall have a minimum diameter at least four inches larger than the diameter of the instrument.

     (2) When sealing with a grout or slurry, the bore hole shall be grouted from the bottom up via a tremie tube. The tremie tube may be left within the bore hole provided: It meets casing standards, is filled completely with grout and the annular requirements of this section are met.

     (3) Ungrouted tubing, piping, liner, or casings shall not be left in the bore hole upon completion.

     (4) Individual transducers may be sand packed provided that the sand pack is not more than five feet in thickness.

     (5) Sealing between sand packed transducers shall be designed and constructed to prohibit flow between monitored zones. At no time shall a vibrating wire piezometer bore hole connect aquifers.



[Statutory Authority: Chapter 18.104 RCW. 09-01-125 (Order 08-10), § 173-160-457, filed 12/19/08, effective 1/19/09.]