Hydraulic Monitoring. Tracers will be used to monitor water movement into and out of the trenches. Tracers will be placed in the cap and on the ground surface to monitor movement of water into the trenches. Tracers will also be added at the bottom of the trenr.hes to determine water movement out of the trenches. For these tests tracers consisting of fluorinated organic anions are to be used. These _ , , , . .* ~ ' ~. Contract No. NRC-04-81-220 Appendix A Page No. 3 . compounds include xx.xx aromatic and aliphatic-ions. The contractor will evaluate analytical techniques for detecting aliphatic fluorinated ions. In conjunction with these advanced tracers, more conventional tracers will ! be used, such as fluorocarbons, inorganic ions including Br- and I- and The conventional tracers will provide- dyes such as fluorescein and rhodamine.
Hydraulic Monitoring. Hydraulic monitoring is conducted to assess the following: • Hydraulic performance of the system with regard to capture zone development; gradient manipulation and plume trajectory; • Effects due to changes in external hydraulic stresses; and • Potential impacts on adjacent plumes. Consistent with Section 2.5 of the RAWP, NEPCS synoptic measurements are taken quarterly to characterize flow directions and system performance (DOE 2018a). Water level measurements taken from MWs and PZs will provide continuing data to assess gradient development and potential changes in hydraulic stress over time. MWs and PZs used for hydraulic monitoring are listed in Table 4 and shown in Figure 2.
Hydraulic Monitoring. Hydraulic monitoring is conducted to verify the hydraulic performance of the system with regard to capture zone development, gradient manipulation and plume trajectory, assessment of effects due to changes in system operations or external hydraulic stresses, assessment of potential impacts on adjacent plumes, provide a basis for groundwater flow model refinement and/or recalibration, and refinement and optimization of system operation, if necessary.
Hydraulic Monitoring. Hydraulic monitoring is conducted to verify the hydraulic performance of the system with regard to capture zone development, gradient manipulation and plume trajectory, assessment of effects due to changes in system operations or external hydraulic stresses, assessment of potential impacts on adjacent plumes, provide a basis for groundwater flow model refinement and/or recalibration, and refinement and optimization of system operation, if necessary. Hydraulic monitoring consists of water level measurements made in a network of monitoring xxxxx (MWs). The spatial distribution of the xxxxx was determined in part using the three-dimensional groundwater flow Table 2. Principal Study Questions, Decision Rules, and Data Needs Question/Goal Decision rule Data needs 1 Are we mitigating the spread of the highest concentration portions of the plume? If field data from the NWPGS well field and mathematical modeling of the plume indicate that the NWPGS is not mitigating the spread of the highest TCE and 99Tc concentration portions of the Northwest Plume, then NWPGS operations will be evaluated and appropriate actions taken. Field data will be collected from the NWPGS well field.a 2 Are we effectively meeting operational goals of 5 ppb or less TCE and 900 pCi/L or less 99Tc discharging from C-612? If discharge levels of TCE exceed 5 ppb or discharge levels of 99Tc exceed 900 pCi/L, then NWPGS operations will be evaluated and appropriate actions taken. TCE and 99Tc samples will be collected from the NWPGS effluent (HV-171). 3 Are we satisfying the regulatory limit of 81 ppb or less for TCE at Outfall 001? If 81 ppb or greater of TCE is detected at the C-612 effluent, then operations will be shut down, the system will be evaluated, and the appropriate actions taken. TCE samples will be collected at HV-171. 4 What levels of TCE are being discharged into the atmosphere? If the NWPGS exceeds its allocated portion of TCE emissions for environmental remediation activities, NWPGS operations will be evaluated and appropriate actions taken. TCE samples will be collected from the NWPGS influent (HV-082) and effluent (HV-171). Mass balance calculations will be performed using the above data. 5 What levels of 99Tc are being discharged to the atmosphere? These data are required to be collected for annual National Emissions Standards for Hazardous Air Pollutants calculations. Technetium-99 samples will be collected from the NWPGS influent (HV-82), air stripper effluent (HV-014), and ...
