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QUALITY ASSURANCE PLAN Procedures to provide data quality should be established and documented so that conditions adverse to quality, such as deficiencies, deviations, non-conformances, defective material, services, and/or equipment, can be promptly identified and corrected. General Sample Collection and Handling Procedures Proper collection and handling are essential to ensure the quality of a sample. Each sample is collected in a suitable container, preserved correctly for the intended analysis, and stored prior to analysis for no longer than the maximum allowable holding time. Details on the procedures for collection and handling of samples used on this project can be found in this section. Soil and Water Sample Labeling and Preservation Label information includes a unique sample identification number, job identification number, date, and time. After labeling all soil and water samples are placed in a resealable plastic bag and placed in an ice chest cooled to approximately 4° Celsius. Upon arriving at the Stratus office the samples are transferred to a secure refrigerator cooled to approximately 4° Celsius. Chemical preservation is controlled by the required analysis and is noted on the chain-of-custody form. Upon recovery, the sample container is sealed to minimize the potential of volatilization and cross-contamination prior to chemical analysis. Soil sampling tubes are typically closed at each end with Teflon sheeting and plastic caps. The sample is then placed in a resealable plastic bag and sealed. The sample is labeled and refrigerated at approximately 4° Celsius for delivery under strict chain-of-custody to the analytical laboratory. Sample Identification and Chain-of-Custody Procedures Sample identification and chain-of-custody procedures document sample possession from the time of collection to ultimate disposal. Each sample container submitted for analysis has a label affixed to identify the job number, sampler, date and time of sample collection, and a sample number unique to that sample. This information, in addition to a description of the sample, field measurements made, sampling methodology, names of on-site personnel, and any other pertinent field observations, is recorded on the borehole log or in the field records. The samples are analyzed by a California-certified laboratory. A chain-of-custody form is used to record possession of the sample from time of collection to its arrival at the laboratory. When the samples are shipped, the person in custody of them relinquishes the samples by signing the chain-of-custody form and noting the time. The sample-control officer at the laboratory verifies sample integrity and confirms that the samples are collected in the proper containers, preserved correctly, and contain adequate volumes for analysis.