One field duplicate;

One equipment rinsate (required only when non disposable equipment is being

used);

One matrix spike (when appropriate for the method); and

One duplicate sample (either a matrix duplicate or a matrix spike duplicate).

Chapter One of SW 846 recommends that a trip blank be prepared and analyzed when

samples are being analyzed for volatile organic analytes. A trip blank should be submitted

with samples each day that samples are collected.

Section 4.4.3 of Chapter One of SW 846 also recommends that the matrix specific

detection limit be determined. This determination does not need to be made on a sample

batch basis, but should be made whenever the matrix is suspected to have altered, or as

frequently as necessary to document that the matrix has not altered. For an aquifer with

relatively static hydrogeological characteristics, this may mean making a matrix specific

detection limit determination twice annually.

7.8.1

Field QA/QC Program

The owner/operator's QAPjP should provide for the routine collection and analysis of

QC samples to verify that the sample collection and handling process has not affected the

quality of the ground water samples. All field QC samples should be prepared exactly as

regular investigation samples with regard to sample volume, containers, and preservation.

The concentrations of any contaminants found in blank samples should not be used to correct

the ground water data. The contaminant concentrations in blanks should be documented, and

if the concentrations are more than an order of magnitude greater than the field sample

results, the owner/operator should resample the ground water. The owner/operator should

prepare the QC samples as recommended in Chapter One of SW 846, at the frequency

recommended by Chapter One of SW 846, and analyze them for all of the required

monitoring parameters. Other QA/QC practices such as sampling equipment calibration,

equipment decontamination procedures, and chain of custody procedures are discussed in

other sections of this Chapter and should be described in the owner/operator's QAPjP.

7.8.2

Laboratory QA/QC Program

The owner/operator's QAPjP should provide for the use of control samples, as defined

in Chapter One of SW 846. The owner/operator should use appropriate statistical procedures

to monitor and document performance and to implement an effective program to resolve

testing problems (e.g., instrument maintenance, operator training). Data from control samples

(e.g., spiked samples, duplicates, and blanks) should be used as a measure of performance or

November 1992

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