WORK PLANS - Laserfiche WebLink

Home Browse Search

A4OM • Inside temperature • Outside weather conditions, temperature, wind speed, wind direction, and barometric pressure • Field duplicate (yes/no) • Initial and final Summa®canister pressures • Sample start and stop times • Sample construction information 4.2 Preparation of Quality Assurance/Quality Control Samples Proper sampling protocols will be used so that samples are representative of the location being sampled, cross-contamination is not occurring, and that the samples are properly preserved andshipped to maintain sample integrity. Standard procedures will include using decontaminated non-dedicated sampling equipment for each sample; wearing a new pair of disposable latex or nitrile gloves for each sample and during the decontamination process; and following strict chain-of-custody procedures and packaging guidelines. The QC samples and QA samples will consist of ambient air samples and sample duplicates. During the monitoring event, field QA/QC samples will be collected and submitted to the subcontracted laboratory for analyses. The QA/QC samples specified for vapor intrusion analyses will include: • Field duplicates — Collected at a frequency of 10% for each matrix type. • Ambient air duplicate samples — Collected at a frequency of one per event 4.2.1 Sample Duplicates The duplicate will be collected by using a T-bar regulator or sample splitter to facilitate the simultaneous collection of two samples. 4.2.2 Quality Control of Field Measurements A program of QC checks will be implemented during the sampling to ensure that physical measurements made as part of the field-monitoring program are precise and accurate. 4.2.3 Precision Precision is the degree of reproducibility of a measured quantity. Precision will be evaluated in the field at the point of measurement. Precision for physical and helium measurements are expected to be achievable to plus or minus the sensitivity of the measuring instruments. Duplicate measurements of helium and pressure must agree to within plus or minus the sensitivity of the instrument or gauge.