Online HAZWOPER Training
Material Sampling Part 2
may be collected using a variety of methods and equipment. The methods
and equipment used are dependent on the depth of the desired sample,
the type of soil, and whether the sample is required to be from disturbed
or undisturbed soil. Once collected, soil samples should be kept at
their in-ground temperature or lower. Refrigeration at 4°C with
a minimal holding time is the best approach. Samples should also be
protected from direct light. The two primary problems associated with
soil sampling involve cross-contamination of samples and improper sample
collection. Therefore, these areas should be addressed in the sampling
plan. Cross-contamination problems can be eliminated or minimized through
the use of dedicated (i.e., assigned only to that purpose) sampling
equipment. If this is not possible, care should be taken to properly
decontaminate equipment. Adhering to proper SOPs can reduce errors due
to improper collection. online hazwoper training
material for HAZWOPER work can be removed to the required depth using spades, shovels,
and scoops. Next, a stainless steel scoop, plastic spoon, or trowel
is used to remove and discard a thin layer of soil from the area that
came into contact with the spade. Most soil types can then be sampled
using a stainless steel scoop or plastic spoon. A flat, pointed mason
trowel may be used to cut a block of soil when undisturbed profiles
are required. One should avoid the use of equipment that is plated with
chrome or other materials. online hazwoper training
Sampling at Given Depths
at certain depths can be taken with various sampling devices, such as
a split spoon sampler, a trier, and an auger. The method and equipment used are dependent on the type
of soil and the type of sample required.
If the soil is not hard and rocky, an auger may be used to bore a hole
to a desired sampling depth. If satisfactory, a sample can be collected
directly from the auger. If a core sample is needed, the auger tip is
replaced with a thin-wall tube sampler. The device is then carefully
lowered down the borehole and driven into the soil. Once it is withdrawn,
the core sample can be collected. Several types of augers are available.
Bucket augers are better for direct sample recovery since they provide
a large volume of sample in a short time.
When continuous flight augers are used, the sample can be collected
directly from the flights, which are usually at five foot intervals.
The continuous flight augers for HAZWOPER work are satisfactory for use when a composite
of the complete soil column is desired.
Post hole augers have limited use for sample collection.
Shallow soil samples can be taken using a trier. The trier must be inserted
at an angle to minimize sample spillage. The trier is rotated once or
twice to cut a core of undisturbed soil. It is then slowly withdrawn
with the slot facing upward.
For undisturbed soil cores 18 to 24 inches in length, a split spoon
sampler is used. It may be used on the soil surface but is generally
used with a power-operated drill rig. The split spoon sampler can therefore
be used in a wide variety of soil types and at greater depths than other
types of equipment.
When a detailed examination of soil characteristics is required, it
may be necessary to excavate a test pit or trench using a backhoe. However,
because of the relatively high cost of the backhoe operation, this is
the least cost effective sampling method.
surface water at shallow depths near the edge of the body of water,
a stainless steel beaker or scoop may be submerged for collection. The
contents can then be transferred to the sample container. By using this
method, the outside of the container does not become contaminated and
require decontamination. To collect a shallow sample that is more than
10 feet from the water's edge, a pond sampler or a small peristaltic
pump with stiff-walled tubing may be used. Surface water may be sampled
at greater depths with an extended bottle sampler or a weighted bottle.
In both cases, the exterior of the bottle is exposed to contamination.
At depths up to 18 to 24 feet, a peristaltic pump may be used. If the
depth exceeds the lift capacity of the pump, a Kemmerer bottle is typically
working around ponds or lagoons, especially in PPE, drowning is a potential
hazard. The PPE can restrict one's movement and vision, resulting in
a trip or fall. Once in the water, the weight of the PPE and the restricted
movement can be deadly. Also, be aware that a SCBA, which is part of
level A or B protection, does NOT work underwater.
Sampling at HAZWOPER Sites
wells, both on-site and off-site, are required for groundwater monitoring
on hazardous waste sites. The installation and operation of these wells
must be planned and supervised by personnel who have extensive knowledge
and experience in hydrology and related subjects.
and operating the well, the following considerations are necessary:
· Well installation plans must be carefully followed to ensure
that the well will provide representative information. The plans will
also help to avoid puncturing through a separating layer to an uncontaminated
aquifer (i.e., a water-bearing rock formation).
· Decontaminate drilling and sampling equipment thoroughly after
to avoid cross-contamination of the next well.
· Avoid overpumping, which can alter groundwater flow or affect
· Proper safety precautions must be taken by sampling personnel.
Any material that comes out of a drill hole or well, either on-site
or off-site, may be contaminated.
It is important to realize that the water standing in a well, and immediately
surrounding a well, does not generally represent the groundwater to
be sampled. Therefore, the well must be purged (i.e., removal of standing
water) before sampling by pumping or bailing. The purged water should
be containerized and stored until samples are analyzed. If the samples
indicate that the purged water is contaminated, the site-specific project
plan should specify the method of handling or disposal.
of purged water to be removed should be specified in the sampling plan.
An alternative to volume-based removal is to monitor the water level,
temperature, conductivity, and pH as the well is purged. When these
factors stabilize, the well is sufficiently purged. Wells may be purged
using a variety of equipment including a gas pressure displacement system,
a submersible pump, and a peristaltic pump. The most complete purging
occurs if water is pumped from just below the water surface. Care must
also be taken to purge the wells at the correct rate to avoid overpumping
and excessive draw-down (i.e., lowering of the water level).
Pressure Displacement System
In a gas pressure displacement system, the water is displaced up the
discharge tube by the increased gas pressure above the water level.
It is particularly useful when the well depth is beyond the lifting
capacity of a peristaltic pump. However, the potential for increased
gas diffusion into the water makes this system unsuitable for when sampling
for volatile (i.e., vaporous) organic compounds or for most pH factors.
Submersible pumps are portable and have relatively high pumping rates.
However, they are heavy, awkward, expensive, and difficult to decontaminate
in the field.
Peristaltic pumps are limited in their lifting capacity; however, they
have an advantage in that the same system can be used not only for purging
but also for sample collection.
pump is useful when relatively large samples are needed. However, a
pump system may strip volatile components as a result of the vacuum
created by lifting. Therefore, volatile organic analysis samples should
be collected using a bailer.
a sample with a peristaltic pump, the following guidelines should be
· Install clean medical-grade silicon tubing in the pump head.
· Attach pump to required length of Teflon suction line; lower
to mid-point of well screen or slightly below the existing water level.
· The first liter of liquid collected is considered a system
· Fill sample bottles, letting the discharge flow gently down
the side of the bottle with a minimum of turbulence (i.e., disturbance).
· Preserve the sample (if directed by EPA sampling guidelines),
check the Teflon liner in the cap, and then secure the cap.
· Complete the label, the chain of custody form, and the log
·Place the sample bottle in a carrying container at 4 degrees C.
· Allow the system to drain, disassemble, and return tubing for
Bailers are useful when samples must be taken from depths beyond a pump's
lifting capacity and when volatile component stripping is a concern.
A bailer allows samples to be recovered with a minimum of aeration (i.e.,
mixing with air). This is accomplished by slowly lowering the bailer
until it contacts the water and then by allowing the bailer to sink
as it fills. The disadvantage of using bailers is that they are time-consuming
because of their limited sample volume. In addition, transfer of the
sample to the collection jar may cause aeration. Pouring the water slowly
down the side of the sample bottle may reduce aeration, by avoiding
Drums are usually opened and sampled in place during site investigations.
However, remedial and emergency operations may require a separate drum
opening area. Procedures for opening drums are the same, regardless
of where the drums are opened. To enhance the efficiency and safety
of drum-opening personnel, the following procedures should be instituted.
If a supplied-air respiratory protection system is used, place a bank
of air cylinders outside the work area and supply air to the operators
via air lines and escape SCBAs. This enables workers to operate in relative
comfort for extended periods of time.
· Protect personnel by keeping them at a safe distance from the
drums being opened. If personnel must be located near the drums, place
explosion-resistant plastic shields between them and the drums to protect
them in case of detonation. Locate controls for drum opening equipment,
monitoring equipment, and fire suppression equipment behind the explosion-resistant
· If possible, monitor continuously during drum opening. Place
sensors of monitoring equipment, such as colorimetric tubes, dosimeters,
radiation survey instruments, explosion meters, organic vapor analyzers,
and oxygen meters, as close as possible to the source of contaminants
(i.e., at the drum opening).
Use the following remote-controlled devices for opening drums:
I. Pneumatically operated impact wrench to remove bungs.
II. Hydraulically or pneumatically operated drum piercers.
III. Backhoes equipped with bronze spikes for penetrating drum tops
in large-scale operations.
a) Do not
use picks, chisels and firearms to open drums
b) Hang or balance the drum opening equipment to minimize worker exertion.
If the drum shows signs of swelling or bulging, perform all steps slowly.
Relieve excess pressure before opening and, if possible, from a remote
location using such devices as a pneumatic impact wrench or hydraulic
penetration device. If pressure must be relieved manually, place a barrier
such as explosion-resistant plastic sheeting between the worker and bung to deflect any gas, liquid, or solids which may be expelled
as the bung is loosened.
d) Open exotic metal drums and polyethylene or polyvinyl chloride-lined
(PVC-lined) drums through the bung by removal or drilling. Exercise
extreme caution when manipulating these containers.
e) Do not open or sample individual containers within laboratory packs.
f) Reseal open bungs and drill openings as soon as possible with new
bungs or plugs to avoid explosions and/or vapor generation. If an open
drum cannot be resealed, place the drum into an overpack. Plug any openings
in pressurized drums with pressure-venting caps set to a 5-psi (pounds
per square inch) release to allow venting of vapor pressure.
g) Decontaminate equipment after each use to avoid mixing incompatible
h) Drum and container sampling can be one of the most hazardous activities
to worker safety and health because it often involves direct contact
with unidentified wastes. When manually sampling from a drum, use the
following safety techniques:
i) Keep sampling personnel at a safe distance while drums are being
opened. Sample only after opening operations are complete.
j) Do not lean over other drums to reach the drum being sampled, unless
k) Cover drum tops with plastic sheeting or other suitable noncontaminated
materials to avoid excessive contact with the drum tops.
l) Never stand on drums. This is extremely dangerous. Use mobile steps
or another platform to achieve the height necessary to safely sample
from the drums.
m) Obtain samples with either glass rods or vacuum pumps. Do not use
contaminated items such as discarded rags to sample. The contaminants
may contaminate the sample and may not be compatible with the waste
in the drum. Glass rods should be removed prior to pumping to minimize
damage to pumps.
of Sampling Equipment
of sampling equipment is dependent on the type of container and the
material to be sampled. Sludge and sediment sampling is similar to soil
sampling in that the material may in some cases be collected as though
it were a solid. Therefore, scoops, triers, corers, or a grain thief
may be used for collection. Again with containerized liquids, the selection
of sampling equipment is dependent on the material and the container.
A device that is commonly used is a drum thief. These glass tubes are
inexpensive and can therefore be disposed of instead of decontaminated.
One draw back is that if the liquid has a low viscosity it may be difficult
to maintain the vacuum in the tube and the sample may dribble from the
tube as it is withdrawn from the drum. Also, glass tubing should not
be used with materials containing hydrofluoric acid or strong alkali
solutions. PVC tubing may also be used in a manner similar to the drum
thief; however, compatibility is a concern. Another common device is
the coliwasa, which is often used for multi-phase samples. However,
the main disadvantage of the coliwasa is decontamination.
methods discussed for surface water sampling may be an option, depending
on the size and accessibility of the container.
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