Collecting Groundwater Samples - Long Island, New York in July 2017

Collecting Groundwater Samples from a Well on Long Island: The image above shows USGS scientists pumping a deep Lloyd aquifer observation well in Long Beach, NY.  To ensure that water-quality samples represent the formation water, the well is pumped for an extended period of time or until at least three casing volumes are removed and measured field parameters have stabilized.  Once the well has been pumped, samples are collected and sent to the USGS National Water Quality Laboratory in Denver, CO for analysis. The water pumped from this well is pristine except for slightly elevated chloride (Public domain).