One of the most frequently asked questions about the HydraSleeve is: "How long does it take for the well to equilibrate or restabilize after the HydraSleeve has been placed in the well?" Unlike Passive Diffusion Bags, the HydraSleeve does not need time for the diffusion process to equilibrate.
Of course there is no one correct answer for every application, it varies and depends on many well-specific conditions such as recovery rate, flow-through characteristics for the aquifer and well screen, the size of the well compared to the size of the HydraSleeve being used, and most importantly how much water is displaced during the placement of the HydraSleeve. For more detailed information on this topic, please follow this link.
Since the weight is the heaviest and largest item being deployed, we thought it would be helpful to provide the displacement information based on the available bottom weights we offer. The flat, ribbon-like HydraSleeve, itself, displaces very little when empty.
| WEIGHT OUNCES | DIAMETER | MLS DISPLACED |
|
5 |
0.75" | 17 mls |
| 8 | 0.75" |
28 mls |
| 8 | 1.25" | 28 mls |
| 11 | 1.25" | 38 mls |
| 16 | 0.75" | 56 mls |
| 17 | 1.25" | 59 mls |
| 23 | 1.25" |
80 mls |
As you can see very little water is displaced when using even the heaviest of our bottom weights. So using this information and the knowledge of your well should allow for an educated idea of how long to leave the first HydraSleeve deployment before retrieving them. Top-weighted HydraSleeves and SuperSleeve assemblies substantially displace more water than a typical bottom-weighted set up; they also require time to allow for the compression of the HydraSleeve into the bottom of the well, so more equilibration time will be necessary for these types of assemblies. Please see this link for a discussion on top weights.
Dye tests have shown that there will be only 3 inches of drag down in a 4-inch column when a 2-inch HydraSleeve is deployed; and there will be 2-feet of drag down in a 2-inch well when a 2-inch HydraSleeve is deployed.
Most HydraSleeve groundwater sampling sites allow for leaving the HydraSleeves in the wells between sampling events, so this equilibration time is usually only considered during the very first deployment. We also now have 2-inch HydraSleeves SpeedBags which are designed to minimize drag down and can retrieved immediately after installing. Here's more information on the NEW SpeedBags.
Please give us a call (800-996-2225) or This email address is being protected from spambots. You need JavaScript enabled to view it. if you have any questions.