Laserfiche WebLink
GROUNDWATER SAMPLING <br /> Prior to collecting a sample of groundwater from a well, the well will be purged by <br /> removing three or more well volumes of water, using either a pump or a batter A well volume <br /> is defined as the amount of groundwater in the well casing and the sand pack in the annular <br /> space surrounding the casing, assuming a sand porosity of 35 percent The pH and electrical <br /> conductivity of the water will be measured periodically dunng the purging <br /> The groundwater sample will be obtained with a teflon bailer equipped with a bottom- <br /> emptying valve To release water from the bailer with minimal aeration, the protrusion on the <br /> bottom-emptying device actuates the bottom check valve and regulates the flow into the sample <br /> bottle <br /> The sample bottle will be obtained precleaned from the analytical laboratory, and it will be <br /> specific with respect to size and material to the type of analysts to be pertormed The bottle will <br /> be carefully tilled to the very top, in order to create a meniscus, and sealed with a teflon-lined <br /> c.ap (septa) These precautions aid in eliminating air from the sample The sample will be <br /> visually inspected to ensure that no air bubbles remain within <br /> Depending on the type of chemical analysis required, samples will be preserved with acid <br /> and/or they are cooled to 4 degrees Celsius Samples then will be labeled, stored, and transported <br /> tri cooled ice chests to the analytical laboratory within the permissible holding time <br />