Envco – Environmental Equipment

ZIST™In-Line characteristics:
•Isolate Well Screen During Purging and Sampling.
•Eliminate Drawdown During Monitoring.
•Limit Groundwater Removal to the Well Screen Zone Only.
•Significantly Reduce Purging and Sampling Time –andCost –throughout the Life of the Project.
•No Bailing.
•Simultaneously Purge Nested and Clustered Well Systems.
•Simultaneously Obtain Water Level Data from All Zones within A Nest or Cluster.
•Compatible with Other Devices: ZIST™ Pumps Can Be integrated with Sensors, and Removed at Any Time.
•Easy to Maintain: O-Ring around ZIST™Tubular Docking Weight Can Be Replaced at Any Time.
•Easily Adapted for Rapidly Decreasing Water Levels.
•ZIST™Can Be Easily Integrated into 3/4-Inch, 1-Inch, 2-inch, 4-Inch and Any Other Well Diameters

Available for new installations or existing groundwater bores

ZIST eliminates drawdown, and reduces purge volume as a result of sampling mechanism. When 3-5 wet casing volumes are required, purge volume is reduced by as much as 60% by ZIST displacement systems.

ZIST™ (patent pending) is the most economic and versatile system for isolating the well screen, eliminating drawdown, and reducing purge volume.

ZIST™ provides verifiable isolation of the well screen when the pump is docked in the Well Screen Receptacle (located between the well screen and riser pipe).

The pump docks with the receptacle and does not sample water from the riser pipe above the receptacle. Drawdown does not need to be monitored.

The pump can easily be removed from the well for maintenance or use of other monitoring devices.

The ZIST™RetroWell can be also used to isolate Passive Diffusion Bags (PDBs), Pressurized Bailers, water-sleeves, and sampling vials in existing 2”, 4”and all other wells. Samples are taken from only the well screen target zone.

In the case of PDBs, diffusion cross-over from riser pipe water is blocked and prevented from potentially biasing the PDB sample. Therefore, diffusion cross-over from riser pipe water is eliminated to prevent potential bias of the PDB sample.