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Remedial Investigation QAPP <br /> Stockton Army Aviation Support Facility,California <br /> well will be developed until the well produces clear (silt-free) water with a minimum of 3 stable water quality <br /> readings as outlined below: <br /> pH -within ±0.2 units. <br /> DO -within±10%. <br /> SC-within ±3%. <br /> ORP-within±10 millivolts(mV). <br /> Temperature -within ±1 degree Celsius(°C). <br /> Turbidity- at or below 10 nephelometric turbidity unit(NTU)or within ± 10% if above 10 NTU. <br /> If the well has slow groundwater recharge and is purged dry,the well will be considered developed when bailed or <br /> pumped dry three times in succession and the turbidity has decreased. If any water is added to the well's <br /> borehole during development or drilling,three times the volume of water added will also be removed during well <br /> development. Groundwater generated during development will be containerized, managed, and disposed of as <br /> investigation-derived waste(IDW)as discussed below in IDW Management(Section 14.2.19). <br /> 14.2.8 Groundwater Sample Collection from Permanent Monitoring Wells <br /> Permanent monitoring wells will be sampled no sooner than 24 hours after completion of well development, in <br /> accordance with Parsons SOP PFAS ENV-03:Groundwater Sampling(Appendix D).The specific monitoring wells <br /> selected for groundwater sample collection are specified in Worksheets#17&#18.The monitoring wells will be <br /> purged using low-flow sampling techniques using a PFAS-free bladder pump,or other sampling device with HDPE <br /> tubing(e.g., peristaltic pump). <br /> Water clarity will be visually monitored and water quality parameters, including DO, SC, ORP, pH, temperature, <br /> and turbidity will be measured using a flow-through cell per the Parsons SOP PFAS ENV-03: Groundwater <br /> Sampling. Readings will be collected every 3 to 5 minutes until the well produces clear (silt-free) water with a <br /> minimum of 3 stable water quality readings, as outlined below: <br /> • pH - within ±0.2 units. <br /> • DO - within ± 10%. <br /> • SC - within ±3%. <br /> • ORP - within ± 10 mV. <br /> • Temperature - within ±3%. <br /> • Turbidity - at or below 10 NTU, or within ± 10% if above 10 NTU. <br /> The multi-parameter water quality meter will be calibrated initially and continually throughout its usage each day, <br /> as needed.A calibration check will be performed at the end of each day. <br /> Once the water quality parameters reach stabilization,each groundwater sample will be collected into laboratory- <br /> supplied bottleware and submitted to the laboratory for analysis of selected parameters.Sample containers will <br /> be PFAS-free, and the samples will not be filtered. In addition, a subsample of each groundwater sample will be <br /> collected in a separate container and undergo a shaker test to identify if there is any foaming. If foaming is <br /> observed,the observation will be noted on the Chain of Custody(CoC)to notify the laboratory prior to analysis. <br /> Groundwater samples from permanent monitoring wells will be analyzed under standard TAT for thetarget list of <br /> 40 PFAS(USEPA Method 1633). The laboratory method DLs for these analytes are presented in Worksheet#15. <br /> PARSONS Worksheet#14&16: Project Tasks and Schedule <br /> Page 68 <br />