Expanded Preliminary Assessment Sampling Plan Guidance
QUALITY ASSURANCE PLAN
The Quality-Assurance Plan should discuss all of the following:
- data-quality objectives for precision, accuracy, and
completeness, including description and frequency of QA/QC samples
to be collected/analyzed, to assess data quality;
- data-quality assessment procedures; and
- data-quality reporting.
The following standards must be maintained during sampling and
analysis to ensure that the data generated for the XPA meets DEQ
- Collect background, duplicate, blank, etc. samples in
percentages or numbers specified below in QA/QC SAMPLING GUIDELINES.
- Use pre-cleaned equipment to perform all sampling , and follow
sampling procedures specified in DEQ or EPA guidance.
- Collect samples in pre-cleaned bottles; label, store, and
transport the samples according to DEQ or EPA guidelines.
- Maintain strict chain-of-custody from sample collection until
the samples are received by the analytical laboratory.
- Use field notes and photographs to document all sampling
activities and any deviations from the original sampling plan.
- All sample analyses must be performed within the holding time
specified for each individual analysis; note any exceptions in the
- Laboratories must follow the individual protocols specified by
EPA or DEQ for the analytical methods used.
- Internal laboratory procedures such as lab blank and surrogate
analysis will be performed as follows, unless otherwise requested by
- all VOC or BNA samples will receive surrogate spike
- matrix spike analysis will be performed on at least every
20th sample; if less
- than 20 samples are collected, at least one matrix spike
analysis will be performed.
- Labs must report results of all internal laboratory QA/QC
procedures such as lab blank, matrix spike, and surrogate analyses.
- In addition to analytical results, analytical data sheets
generated by the laboratory for the XPA will each contain the
following information: sample number and laboratory identification
number, analysis method type or number, detection limits, and date
- The lab must document any problems it encounters regarding
chain-of-custody, sample holding times, sample analyses, lab
contamination, etc., and these must be discussed in the XPA report.
QA/QC Sampling Guidelines
Sampling to determine the background levels of naturally
occurring and man-made chemicals should be carried out as part of
any routine sampling program. Background areas should be removed
from facilities that may have contributed contamination to the
environment, and should be upgradient, upwind, and upstream of such
facilities. These areas should also be near enough to the site to
have similar topographical features and the same or very similar
soil types. The parent material for the soil should be the same, if
at all possible. Collect at least one background sample, when
appropriate, for each sample matrix and parameter selected.
Background samples should be preserved, packaged, and sealed the
same way as any other sample. Assign a separate sample number to
each background sample, and submit it "blind" to the laboratory.
Duplicates are two identical samples collected at the same time
from the same source, but placed in separate sample containers. The
purpose of collecting a duplicate is to assess laboratory
performance by comparing what should be identical results. Duplicate
samples should be collected from areas of known or suspected
contamination, and should make up at least 10 percent of samples
from each sample matrix and every analytical group to be tested.
Blanks are used to determine whether sampling equipment, sampling
technique, or sample transport has induced contamination that is not
actually present in the environment. When required, one blank sample
should be collected per day. There are several types of blanks, as
- Equipment Blanks
An equipment blank should be collected when sampling equipment
is decontaminated and reused in the field, or when a sample
collection vessel (bailer, beaker) will be used. Equipment blanks
are designed to evaluate field sampling and decontamination
procedures. These blanks are prepared by passing organic-free (for
organics) or deionized water (for inorganics) through decontaminated
sampling equipment before filling the sample bottles. One equipment
blank should be prepared per day when equipment blanks are needed.
Note that the use of dedicated sampling equipment eliminates the
need for blanks.
- Field Blanks
Collect this type of blank when equipment decontamination is not
necessary and when a sample collection vessel will not be used
(bailer, pump, etc.). The purpose of field blanks is to evaluate the
general sampling environment. The field bottle blank should be
poured at a sampling point. Use the appropriate "blank" water:
organic-free water for organic parameters, and deionized water for
- Trip/Travel Blanks
Trip or travel blanks evaluate potential sample contamination
from volatile organic compounds (VOCs) that may be present in the
air on-site or in sample shipping containers. A trip blank consists
of laboratory distilled, deionized water in a closed container. The
blank accompanies the empty sample bottles to the field as well as
the samples returning to the lab for analysis; it is not opened
until the lab analyzes it with the actual site samples. When needed,
one trip blank should be prepared by the sample laboratory and
analyzed upon return for each sampling event.
Laboratory QC Samples
Laboratory quality control (QC) samples should be collected and
analyzed as part of standard laboratory protocols. A laboratory QC
sample is not an extra sample, but consists of additional sample
volume from specific sample locations where there is known or
suspected contamination. For a given sample, this extra volume
provides the laboratory with sufficient material to duplicate its
analyses or conduct matrix spike analyses. Bottle labels, traffic
reports, and chain-of-custody records for these samples must
identify them as laboratory QC samples. Designate one field sample
per week or one per 20 samples (including blanks and duplicates),
whichever is greater, as the QC sample. It is good practice to check
with the analytical laboratory regarding the additional sample
volume required for laboratory QC samples prior to sampling.
Health and Safety Plan
Prepare a Health and Safety Plan with the XPA sample plan for all
sites where DEQ personnel or persons performing contract work for
DEQ will be involved in on-site activities. At a minimum, the Health
and Safety Plan should:
- Describe known site hazards and risks;
- Identify appropriate levels of protective clothing and equipment
for site work;
- Describe decontamination procedures and means of handling,
storing, and disposing of investigation-derived wastes;
- Identify any special requirements or training needs, and verify
that all staff participating in site work are adequately trained;
- Outline a contingency plan for emergencies.