Environmental Engineering Reference
In-Depth Information
4.1.5 Selection of Sampling Equipment
Several factors need to be considered when selecting sampling equipment. The ease
of use and decontamination of the device, physical location of the sampling point, and
the type of sample matrix are some of the factors. While matrix type is a determining
factor, the materials of sampling equipment are of general importance to all sampling
medium. The compatibility of contaminants being sampled with the composition of
sampling device is a priority because contaminants can be contributed to or removed
from the sample. Sampling equipment can be made of plastic, glass, Teflon, stainless
steel, or other materials. Like sample containers, plastic is generally used when
analyzing metals. Teflon or stainless steel is used when analyzing for organic
compounds. Most of the sampling tools are commercially available or can be custom-
made. This section presents the sampling equipment most commonly used in surface
water, wastewater, groundwater, soil and sediment, wastes, biological samples, and
air matrices.
Surface Water and Wastewater Sampling
In Figure 4.3, three common sampling tools are depicted: the pond sampler, the
weighted bottle sampler, and the Kemmerer bottle. The pond sampler (grab sampler)
is used for near shore sampling where cross-sectional sampling is not appropriate. It is
also used for sampling froman outfall pipe along a disposal pond, lagoon, and pit bank
where direct access is limited. The weighted bottle sampler is used to collect samples
in a water body or impoundment at a predetermined depth. The Kemmerer bottle is a
Teflon, acrylic, or stainless steel tube attached to a rope, and it has stoppers at each
end. It is best used when access is from a boat or structure such as a bridge or pier, and
where discrete samples at specific depths are required. When the Kemmerer bottle
lowers vertically into the water at the desired depth, a ''messenger'' is sent down to
the rope and hits the trigger to close the stoppers. The van Dorn sampler is a slight
(a)
(b)
(c)
Messenger
Cable
Trip head
Upper stopper
C hain
Washer
Cork
Eyelet
Ungrip clamp
Center rod
Cork
Pin
DCK hole
Berier polypropylene
250 ml (1 ml)
Body
Washer
Nut
Pole telescoping aluminum heavy
duty 250-450 cm (96-180 in)
1000 ml (1-00) Weighted
betria cacher
Lower stopper
Bottom
chain
Figure 4.3 Common sampling tools used for surface water and wastewater: (a) Pond sampler,
(b) Weighted bottle sampler, and (c) Kemmerer bottle sampler (U.S. Army Corps of Engineers, 2001)
 
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