Does it make sense to use historical purge volumes along with parameter stabilization with low-flow purging?

If you are talking about historical purge volumes from previous low-flow events, it's not a bad idea to use as a target because your new volumes shouldn’t be far off unless you had a significant change in the wells. But, if you are talking about comparing it to historical purge volumes and three to five volume purging, there really is no basis for this. Low-flow purging and sampling purge volume are really based entirely on indicated parameter stabilization. In fact, because of changes in chemistry or water levels, it's important to watch for indicator parameter and water level stabilization in order to determine when purging is completed because it could vary with those changes.