| Use: | Jetting methods have potential use for monitoring well and piezometer installation in unconsolidated formations. |
Description:
The jetting method utilizes either a wash pipe placed inside a well screen or a string of 2-inch pipe set adjacent to the well point. Water is pumped into the casing or into the pipe string allowing the well screen and casing to sink into the formation by its own weight. Cuttings are brought to the surface by water rising outside the casing or jet pipe. At depths below 25 feet, a drilling fluid additive must be mixed with the jetting water to suspend cuttings and stabilize the borehole when circulation is interrupted.
The jet percussion method uses a wedge-shaped drill bit at the end of the drill pipe attached to a cable, which is alternately raised and dropped to loosen unconsolidated material or the breakup rock at the bottom of a borehole. The drill pipe is rotated by hand at the surface. A casing is advanced by a drive pipe as the depth of the hole increases. Water or drilling fluid is pumped down the drill pipe under pressure and discharged through ports on each side of the drill bit for lubrication. The water also carries cuttings up the borehole between the drill pipe and casing to the surface where they are deposited in a settling pipe. The drilling fluid is then recirculated back down the drill pipe.
Analytes:
| 2. Non-Halogenated SVOCs | 6. Pesticides/Herbicides | 10. Explosives |
| 4. Halogenated SVOCs | 7. Metals | 11. TPHs |
| 5. PAHs | 8. Radionuclides |
Media:
| Soil: | Ground Water: | Surface Water: | Gas/Air: |
| MAXIMUM | MAXIMUM | Not Applicable | MAXIMUM |
Use of water or drilling fluid during this process might affect sample quality.
| Maximum Depth: | Less than 50 feet. |
| Production Rate: | Sample is available quickly. Comparatively fast method for shallow boreholes in unconsolidated sediments. Operational speed slows as depth increases. |
| Investigation Derived Waste Volume: | Large volume of waste. |
| Technology Status: | Commercially available and routinely used field technology. |
| Certification/Verification: | Technology has not participated in CalEPA certification and/or CSCT verification program. |
| Relative Cost per Sample: | Least expensive. Comparatively inexpensive to other open hole methods. |
Limitations:
ASTM Standards/EPA Methods:
No applicable ASTM standards or EPA methods are cited for this technology.
| Previous Page | Sample Access/Collection Matrix | Sample Analysis Matrix | Home | Areas of Interest | Next Page |