Step 19) Lower the CMT Multilevel System
Lower the assembled CMT System into the borehole slowly.
If buoyancy is a problem, wait, as the channels below water level will slowly fill and allow the system to be lowered further. To speed this process along, pour or pump clean water into the vent holes.
When the required depth is reached, suspend the system with the System Support Clamp (Figure 20) to prevent it from moving during well construction.
Figure 20 - 3 Channel CMT Multilevel Monitoring System Wellhead Manifold
Once the backfilling operation is complete, the System Support Clamp is removed and can be reused for the next installation.
Complete the installation by carefully pouring or using a tremie to place sand and bentonite at appropriate levels to seal the borehole annulus.
Solinst has developed special tubing centralizers that ensure that the tubing is centered in the borehole during well construction. The fins on the centralizers are low-profile to prevent them from obstructing the tremie tube, or sand and bentonite pellets poured from the surface.
Attaching the Standard Wellhead
(after the well has been installed)
Avoid using "single lifts" of grout greater than 50 ft.. in the unsaturated zone.