Laserfiche WebLink
41h Qtr 2020 GW/SW Report <br /> Review Memo No.2 <br /> Cresson Project(M1980-244) <br /> 7. Provide a table of all the groundwater monitoring well locations that are sampled on a quarterly basis <br /> and details on how each location is sampled. If the location has a dedicated pump indicate the type, <br /> e.g. submersible, bladder, etc. For non-dedicated sampling locations indicate what equipment is used <br /> to purge the well and collect the sample. <br /> 8. The Division is discouraged that a bird's nest was not noticed by the field technician during the initial <br /> round of sampling. Hopefully with more thorough training, obvious items such as a nest in the well <br /> head will not go unnoticed in the future. On March 16, 2021 the operator notified the Division of the <br /> pump failure at CRMW-3B and the subsequent removal and replacement of the pump on April 12. <br /> Did the pump fail due to bio-fouling? If not, what is the reason for the pump's failure as it is the <br /> Division's understanding that the pump was replaced at approximately the same time last year due <br /> to bio-fouling. <br /> 9. Response was adequate. <br /> 10. Response was adequate. <br /> 11. The Operator's response includes a statement when a sufficient water volume has been evacuated to <br /> complete the necessary purging. However, in the QAPP Section 8.5, it states"When sampling a low <br /> yield well evacuate the well to dryness once. Within 24 hours of this purge, collect, preserve, and <br /> handle the sample(s) according to normal procedures." It is the Division's understanding that no <br /> additional purging is required after a well has been purged dry, only returning within 24 hours to <br /> collect what sample volume is available. Please affirmatively state the QAPP will be followed and <br /> commit to returning to a well that has been purged dry within 24 hours to collect a sample. <br /> 12. Please provide the diameters and screen lengths for monitoring wells PGMW-3 and VIN-2A. It is the <br /> Division's opinion that the two wells have suitable volume to be purged and sampled. <br /> • PGMW-3 has 4.8 feet of saturated thickness, in a 2-inch diameter well that is approximately <br /> 0.8 gallons per well volume or 3 gallons per well volume in a 4-inch well.These well volumes <br /> can be purged using readily available sampling equipment. <br /> • At VIN-2A there is 10 feet of saturated thickness which equates to 1.6 and 6.5 gallons per well <br /> volume in a 2 inch and 4 inch well, respectively. Depending on how productive the well is <br /> there should be sufficient volume in the well to purge the well dry(returning later to collect a <br /> sample) or continue to purge for sample collection using the proper sampling equipment. <br /> It is incumbent on the Operator to collect as many samples as possible to ensure the impact to the <br /> hydrologic balance has been minimized by monitoring for any possible offsite impacts to <br /> groundwater quality and quantity. <br /> 13. Response was adequate. <br />