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Remedial Investigation QAPP Stockton Army Aviation Support Facility,California The required sample containers, preservatives,and holding times are specified in Worksheets#19&#30. Non- disposable sampling equipment will be decontaminated between each well.The list of permanent monitoring wells to be sampled is specified in Worksheets#17&#18. Refer to Parsons SOP PFAS ENV-03:Groundwater Sampling(Appendix D)for additional details. 14.2.9 Hydraulic Conductivity (Slug)Tests In-situ hydraulic conductivity test data,via rising or falling head slug tests,will be conducted at select permanent monitoring wells to assess the hydraulic conductivity of the soil surrounding the tested monitoring well.Hydraulic conductivity values can be used to estimate rates of groundwater flow, estimate responses of aquifers to applied stresses (such as pumping), estimate the rate of movement of various chemicals in subsurface zones, and construct and calibrate groundwater flow models.The specific monitoring well locations where slug tests will be completed are specified in Worksheets#17&#18. The slug testing will commence after sampling once the well has returned to equilibrium (wells screened in low permeability zones may require additional time to reach equilibrium). An initial round of static water level measurements will be collected prior to initiating the slug tests. Standard slug test techniques will be used at monitoring wells. The standard slug test will entail measurement of water level changes resulting from submergence or withdrawal of a solid cylinder of known volume. Water levels will be monitored and recorded until the water level returns to static conditions or sufficient data are collected to perform the hydraulic conductivity calculations. The response of the water level will be monitored using an In-Situ Level Troll 700 Data Logger,or equivalent.The datalogger will be lowered into each monitoring well and hung at a field-determined depth below top of casing. The datalogger depth will be set low enough to fully submerge the slug. Each datalogger will be programed using a Win-Situ Software application through use of an In-Situ Rugged Reader, laptop, tablet, or cell phone. Test results will be monitored in real-time in the field. Equipment that comes into contact with groundwater will be decontaminated between each test location. Hydraulic conductivity will be conducted in accordance with Parsons SOP PFAS ENV-07:Hydraulic Conductivity(Slug) Testing(Appendix D). 14.2.10 Surface Water, Sediment, Stormwater, and Stormwater-Transported Solids Sample Collection The Rydberg Creek engineered conveyance is located adjacent to the property to the south. No samples were collected from the drainage duringthe SI.Therefore, RI Mobilization 1 will focus on surface soil sample collection at various points along the Rydberg Creek conveyance. Specific sampling locations are specified in Worksheets #17&#18.Sample locations will be photo-documented and recorded with a hand-held GPS device. Rydberg Creek is ephemeral and dry except during precipitation events,and it is assumed that water will not be flowing during Mobilization 1. Surface soil samples will be collected from the Rydberg Creek conveyance at various points along the drainage, including upstream and downstream of the Facility, following soil sampling procedures,as described in Section 14.2.2. If surface runoff water is present during Mobilization 1,then surface water and stormwater-transported solids samples will be collected at the same proposed locations. If surface runoff water and/or stormwater-transported-solids are present during Mobilization 1, the following protocol will be used. If surface runoff water and/or stormwater-transported solids samples from different locations within the Creek are scheduled to be collected on a short period of time(e.g.,one day),sampling order will begin at the most downgradient location towards the most upgradient location. Water samples will be collected first at each location, prior to soil or stormwater-transported solids sampling. The water samples will PARSONS Worksheet#14&16: Project Tasks and Schedule Page 69