WORK PLANS - Laserfiche WebLink

Home Browse Search

ERM Mike Quillid, CPESC, PMP, QSD 26 May 2023 Page 5 specific conductivity, dissolved oxygen, and oxidation-reduction potential will be monitored and recorded prior to sample collection. Stabilization of groundwater parameters will be attempted and sediment in the purge water will be removed to the extent possible during purging.Sampleswill becollected directlyfrom the pump discharge tubing. Samples will be collected into laboratory-provided bottles for analysis. Boringswill be abandoned using neat cement grout. Grout will be applied to the boreholes via tremie pipe if required by the SJEHD permit, based on the depth of the borehole and the thickness of standing water present in the borehole. 4.3 Groundwater Sampling of Existing Site Well Sampling of existing well 95215 will be performed to assess deep groundwater conditions at the Site. Well 95215 will be sampled from the sample port located on the wellhead. Prior to sampling, ERM will purge at least one casing volume of water to purge potentially stagnantwater in the well. Groundwater parameters(including temperature, pH,conductivity, dissolved oxygen, oxidation reduction potential, and turbidity); purge flow rate; and depth to water will be monitored and recorded on the sampling forms. Groundwater sample collection field forms will be completed to document sampling. After purging,samples will be collected into laboratory-provided bottles for analysis. 4.4 Groundwater Analytical Testing After collection, groundwater samples will be preserved on ice, transported under chain-of- custody, and analyzed by Eurofins TestAmerica, a state-certified laboratory accredited with the Environmental Laboratory Accreditation Program, for the following: ■ California Assessment Manual 17 (USEPA) Method 6020 (field filtered) ■ TPH-d and TPH-mo by USEPA Method 8015M without silica gel cleanup ■ TPH-g and VOCs by USEPA Method 8260B 4.5 Quality Assurance/Quality Control Quality assurance/quality control (QA/QC)samples will include method blanks, laboratory control samples, laboratory control sample duplicates, matrix spike, and matrix spike duplicates performed by the laboratory per analytical package. Field QA/QC groundwater samples will be collected as outlined in the subsections below. If soil samples are collected, the same QA/QC sample guidance will be followed. 4.5.1 Duplicates Field staff will collect one field duplicate for every 20 groundwater samples or one per event, whichever is higher. Field duplicates will be labeled with a sample designation and will be used to assess the relative percent difference(RPD)for laboratory precision on various analytes. Staff will document which sample the duplicates correspond to on appropriate field sampling forms (e.g., field notes and soil boring log or groundwater sampling form), and ultimately stored in the central