Standpipe Piezometer CP1, CP15

How it works

As a piezometer, the filter sits in a sand intake zone at the depth where pore-water pressure is to be monitored, sealed above with a bentonite pellet or chip seal and the rest of the borehole backfilled with grout. As a monitoring well, the filter is attached to a riser and backfilled with sand to within a few metres of the surface, with a bentonite seal at the top to keep runoff out.

Water enters the riser pipe until the water pressure inside the filter equals the pressure in the surrounding soil; a water level indicator is then lowered down the riser to measure the depth of water.

CP1 vs CP15

The CP1 is a porous plastic filter inside a perforated rigid PVC body. The CP15 uses a crush-resistant porous plastic filter and can be paired with a PWS piezometer where continuous monitoring is needed. Both are used with rigid PVC riser pipes.