Bailer
Encyclopedia
A bailer in hydrogeology
is a hollow tube used to retrieve groundwater samples from monitoring wells. Groundwater monitoring wells are drilled in areas where there are underground storage tanks or where there is environmental remediation occurring. The wells are typically built out of PVC casing which is slotted to allow groundwater to flow freely through the well. Bailers are tied to a piece of rope (usually made from nylon
or polypropylene
) or a piece of wire (composed of Teflon or stainless steel) and lowered into the water column. Once lowered, the bailer uses a simple ball check valve
to seal at the bottom in order to pull up a sample of the groundwater table. Bailers can be disposable or reusable, and they are made out of polyethylene, PVC, FEP or stainless steel.
There are advantages and disadvantages to using bailers for groundwater sampling. Bailers are simple devices to use and are relatively inexpensive. Disposable bailers are usually cleaned to United States Environmental Protection Agency
specifications and individually packaged to protect sample integrity. In addition, bailers can be lowered to any depth while pumps have sharp limitations on the depth of the well. The main drawback of using bailers is aeration of the water as the sample is obtained, which could release volatile organic compounds that need to be tested. Also, if there is a high amount of sediment or turbidity
, this may interfere with the ball check valve seating correctly.
The term “bailer” is also used colloquially in British English to refer to someone who reneges on a commitment, e.g. “Sarah D bailed on going to Spain. Sarah D is a bailer”. The term is also used less formally in British English to describe someone who is unreliable or is less than trustworthy, e.g. "I wouldn't ask Sarah to do that, Sarah is a bailer".
Hydrogeology
Hydrogeology is the area of geology that deals with the distribution and movement of groundwater in the soil and rocks of the Earth's crust, . The term geohydrology is often used interchangeably...
is a hollow tube used to retrieve groundwater samples from monitoring wells. Groundwater monitoring wells are drilled in areas where there are underground storage tanks or where there is environmental remediation occurring. The wells are typically built out of PVC casing which is slotted to allow groundwater to flow freely through the well. Bailers are tied to a piece of rope (usually made from nylon
Nylon
Nylon is a generic designation for a family of synthetic polymers known generically as polyamides, first produced on February 28, 1935, by Wallace Carothers at DuPont's research facility at the DuPont Experimental Station...
or polypropylene
Polypropylene
Polypropylene , also known as polypropene, is a thermoplastic polymer used in a wide variety of applications including packaging, textiles , stationery, plastic parts and reusable containers of various types, laboratory equipment, loudspeakers, automotive components, and polymer banknotes...
) or a piece of wire (composed of Teflon or stainless steel) and lowered into the water column. Once lowered, the bailer uses a simple ball check valve
Check valve
A check valve, clack valve, non-return valve or one-way valve is a mechanical device, a valve, which normally allows fluid to flow through it in only one direction....
to seal at the bottom in order to pull up a sample of the groundwater table. Bailers can be disposable or reusable, and they are made out of polyethylene, PVC, FEP or stainless steel.
There are advantages and disadvantages to using bailers for groundwater sampling. Bailers are simple devices to use and are relatively inexpensive. Disposable bailers are usually cleaned to United States Environmental Protection Agency
United States Environmental Protection Agency
The U.S. Environmental Protection Agency is an agency of the federal government of the United States charged with protecting human health and the environment, by writing and enforcing regulations based on laws passed by Congress...
specifications and individually packaged to protect sample integrity. In addition, bailers can be lowered to any depth while pumps have sharp limitations on the depth of the well. The main drawback of using bailers is aeration of the water as the sample is obtained, which could release volatile organic compounds that need to be tested. Also, if there is a high amount of sediment or turbidity
Turbidity
Turbidity is the cloudiness or haziness of a fluid caused by individual particles that are generally invisible to the naked eye, similar to smoke in air. The measurement of turbidity is a key test of water quality....
, this may interfere with the ball check valve seating correctly.
The term “bailer” is also used colloquially in British English to refer to someone who reneges on a commitment, e.g. “Sarah D bailed on going to Spain. Sarah D is a bailer”. The term is also used less formally in British English to describe someone who is unreliable or is less than trustworthy, e.g. "I wouldn't ask Sarah to do that, Sarah is a bailer".