Ground Water Sampling

ETL 1110-1-171

31 Jan 96

(b) The volume of one soil sample retrieved by the SCAPS is

usually smaller than that obtained by conventional drilling

methods. At least three manufacturers currently offer soil

samplers. The dimensions of each sample barrel are 25.4 mm inside

diameter (I.D.) by 203.2 mm; 35.6 mm (I.D.) by 533.4 mm; and 35.6

mm (I.D.) by 990.6 mm. Assuming a soil density of 1.7

grams/cubic cm, sample barrels can contain approximately 175

grams, 900 grams, or 1675 grams of material respectively.

(2)

Ground Water Sampling:

(a) SCAPS can use commercially available ground water sample

probes such as the HydroPunch IITM (HP II). The body of the HP

II is attached to the push rods and samples are collected in one

of two ways:

- The manufacturer refers to the first way as the

hydrocarbon mode. A 1.5-meter long disposable screen and tip is

inserted into the HP-II, the HP-II is pushed to the desired depth

and the outer body of the HP-II is retracted. The disposable

screen is exposed to the ground water and a 19 mm I.D. bailer is

lowered through the rods and into the screened zone for sample

collection.

- The manufacturer refers to the second way as the ground

water mode. The HP II is fitted with a check valve assembly and

pushed. At the desired depth, the body of the HP II is retracted

about 0.3 meters. Water enters a 101.6 mm long screen within the

body of the HP II. When the HP II is full, the entire sampler is

retrieved and the sample is decanted through the check valves.

(b) Other commercially available ground water sample probes

such as the Bengt-Arne Torstensson (BAT)(R) sampler, and the

Westbay(R) MP may be compatible with SCAPS.

(c) SCAPS can also be used to install ground water sampling

points made of 12.7 mm I.D. or 38.1 mm I.D. polyvinyl chloride

(PVC) casing and screen. The casing and screen are flush jointed

and available in one meter or 1.5 meter lengths. The screen slot

size is usually 0.25 mm. The 12.7 mm I.D. PVC can be emplaced

two different ways:

- One way is by using the PowerPunchTM system. This

commercially-available system has a screen inside a drive casing.

This assembly is driven to depth with special 47 mm O.D. rods

fitted with o-ring seals. The 12.7 mm I.D. PVC is emplaced

through the center of the rods and fitted to the screen. The

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