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10.2.3.
Types of Assessments
MERC employs several QA assessment tools designed to provide a better understanding of the
components of, and basis for improving, the MERC Quality Management System (Table 4). Internal
(programmatic) and external QA audits are one of the principal tools for determining the effectiveness of
the MERC QA/QC components. QA audit frequency and scheduling will vary with the type of review
conducted. Specifics of frequency and type of review will be outlined in the QAPP and/or individual Test
Plans.
Table 4. MERC QA Assessments
Assessment Type
Assessors
Document Reference Reason for
Assessment
Minimum Frequency
Performance
Evaluation
Program
Coordinator, QA
Manager,
QAPP, SOPs, Test
Plans
Assess measurement
performance
Each test as
applicable
Technical System
Audit
QA Manager
QAPP, Test/ Plans
Assess technical
quality of BWTS
test
Once per test.
Audit of Data
Quality
QA Manager
Raw data and data
summary
Assess data
calculations and
reporting
At least 10% of test
data
Data Quality
Assessment
QA Manager
QAPP, SOPs, Test
Plans
Assess instrument
accuracy and
precision
QC tests equal to
10% of samples
Data Validation and
Verification
QA Manager
Raw data and data
summary
Assess compliance
of dataset with
DQOs and analytical
quality of dataset
Once per test
The following is a description of some of the evaluation tools:
10.2.3.1.
Performance Evaluation Audits
Performance evaluation (PE) audits are quantitative evaluations used to assess the ability of a laboratory,
or field measurement system, to provide reliable data. PE audits should be conducted whenever a
reference method is available or whenever a technology will measure a parameter for which a reference
sample is available. PEs samples will be considered for all laboratories providing analytical services,
directly or indirectly, for MERC and will be traceable, whenever possible, through the National Institute
of Standards and Technology (NIST). The evaluation consists of providing a reference, "blind" or “double
blind” sample, to the laboratory for analysis. A PE sample contains known concentrations the chemical
or biological analyte of interest and will normally be in the appropriate media (e.g., water, sediment). The
analytical results obtained by the laboratory are compared to the known concentrations of the analyte
contained in the PE sample(s), as a means of determining if the laboratory demonstrated its ability to
properly identify, and quantify, an analyte within established, or calculated, control limits.
The type and frequency of PE audits to be performed are specified in the QAPP and/or Test Plan for each
BWTS test. The value or composition of reference materials must be certified or verified prior to use, and
the certification or verification must be adequately documented. The MERC QA Manager will review
results of PE audits.