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Monitoring Well Sampling. SAP (Sampling Analysis Plan) Frequency Purging Pumps and Bailers Bottles and Materials. SAP Sampling Analysis Plan. Written statement of sampling objectives Provides a schedule Procedures Written documentation for outside evaluation Vehicle provisions.
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SAP (Sampling Analysis Plan) • Frequency • Purging • Pumps and Bailers • Bottles and Materials
SAPSampling Analysis Plan • Written statement of sampling objectives • Provides a schedule • Procedures • Written documentation for outside evaluation • Vehicle provisions
Sample Point Inspection • Prior to sampling, inspect the well • Identifying markers • Is surface sealed • Check for weathering of outer surface
Headspace Screening • Record ambient or background readings • Water Level Measurement • According to Sampling Analysis Plan • Well Purging and Field Parameter Measurement • Select purging device based on possible material/sample interactions • Corrosion of steel parts • Low pH, high O2 content, high CO2, high TDS, high iron bacteria… • Degradation of plastic materials • High concentrations of chlorinated solvents • Adsorption and later desorption of metals or organic compounds from solid surfaces • Leaching from plastic materials • Pumps vs. bailers • Low flow vs. high flow return rates • Dedicated vs. portable purging/sampling equipment • If multiple samples are necessary, dedicated equipment will ease the decontamination process • Cost of purchase and operation • Calibrate the equipment • Organize all supplies • Gloves, sample containers, preservatives, filters, labels, field notebook, etc.
Sample Collection Procedures • Order of container filling
Sample Collection Protocols • Sample should never come in contact with anything but the interior of the sample container (cannot touch the mouth of the container) • Caps kept on container until the moment the container is to be filled • As little atmospheric influence a possible, little contact with ambient air • For VOCs, no headspace, need a positive miniscus • Collection field QC Samples • Trip blanks, temperature blanks, field blanks, equipment blanks, blind duplicate blanks, field spiked blanks, field split blanks
Pretreatment Procedures • Filtration
Preserving • Physical • Appropriate container • Adequate packing • Adequate temperature
Chemical Preservatives
Cleaning the equipment • Water-level gauges, probes, flow-thru cells, pump and tubing • Delivery to lab