FRTR Field Sampling and Analysis Technologies Reference Guide

3 ACCESS TOOLS

3.3 DRIVE METHODS

3.3.2 Direct Push Sampler

Use:

Direct push is a relatively new technology that has gained rapid acceptance as a preliminary reconnaissance method. This method is used to collect representative ground water samples in unconsolidated material without having to install permanent ground water monitoring wells.

Description:

Direct push sampling involves pushing a small-diameter hollow steel rod into the ground to a selected depth and extracting a small water sample, and can be used in most materials that can be augered or sampled with a split spoon. It can be attached to cone penetrometer rods and driven into the soil with hydraulic rams. When the bottom of the probe is at least 5 feet below the water table, the outer cylinder is pulled back, exposing a perforated stainless steel sample entry barrel covered with either a nylon or polyethylene filter material. Hydrostatic pressure forces ground water that is relatively free of turbidity into the sample compartment, and the probe is pulled to the surface to retrieve the sample.

Analytes:

1. Non-Halogenated VOCs	5. PAHs	9. Inorganics
2. Non-Halogenated SVOCs	6. Pesticides/Herbicides	10. Explosives
3. Halogenated VOCs	7. Metals	11. TPHs
4. Halogenated SVOCs	8. Radionuclides

Media:

Soil:	Ground Water:	Surface Water:	Gas/Air:
MINIMUM	MODERATE	Not Applicable	MODERATE

Maximum Depth:	Up to 100 feet. If deeper measurements are desired, boreholes can be drilled to the appropriate depth.
Production Rate:	Sample is available quickly.
Investigation Derived Waste Volume:	Small volume of waste.
Technology Status:	Commercially available technology with moderate field experience.
Certification/Verification:	Technology has not participated in CalEPA certification and/or CSCT verification program.
Relative Cost per Sample:	Least expensive.

Limitations:

Provides one-time sample only.
Can not be used in very gravelly or consolidated formations.
Samples must be taken 3 to 5 feet below the water surface, meaning the light nonaqueous phase liquid floating at the surface might be missed during sampling.
Collection of samples in clayey zones requires excessive fill times (up to 2 hours), and filter mesh might allow significant uptake of fines in the sample.
Small diameter well screen may be hard to develop.

ASTM Standards:

D 6001

Guide for Direct Push Water Sampling for Geoenvironmental Investigations.

Sample Access/Collection Matrix

Sample Analysis Matrix

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