{{Unreferenced, date=December 2007 Groundwater bailer with reel

A bailer in

hydrogeology Hydrogeology (''hydro-'' meaning water, and ''-geology'' meaning the study of the Earth) is the area of geology that deals with the distribution and movement of groundwater in the soil and rock (geology), rocks of the Earth's crust (ge ...

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 An underground storage tank (UST) is, according to United States federal regulations, a storage tank, including any underground piping connected to the tank, that has at least 10 percent of its volume underground. Definition & Regulation in U.S. ...

or where there is

environmental remediation Environmental remediation deals with the removal of pollution or contaminants from environmental media such as soil, groundwater, sediment, or surface water. Remedial action is generally subject to an array of regulatory requirements, and may ...

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 is a generic designation for a family of synthetic polymers composed of polyamides ( repeating units linked by amide links).The polyamides may be aliphatic or semi-aromatic. Nylon is a silk-like thermoplastic, generally made from pet ...

polypropylene Polypropylene (PP), also known as polypropene, is a thermoplastic polymer used in a wide variety of applications. It is produced via chain-growth polymerization from the monomer propylene. Polypropylene belongs to the group of polyolefins an ...

) 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 A check valve, non-return valve, reflux valve, retention valve, foot valve, or one-way valve is a valve that normally allows fluid (liquid or gas) to flow through it in only one direction. Check valves are two-port valves, meaning they have ...

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. A bailer in words is called an "Anouar". 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 The Environmental Protection Agency (EPA) is an independent executive agency of the United States federal government tasked with environmental protection matters. President Richard Nixon proposed the establishment of EPA on July 9, 1970; it ...

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 Volatile organic compounds (VOCs) are organic compounds that have a high vapour pressure at room temperature. High vapor pressure correlates with a low boiling point, which relates to the number of the sample's molecules in the surrounding air, ...

that need to be tested. Also, if there is a high amount of sediment or

turbidity Turbidity is the cloudiness or haziness of a fluid caused by large numbers of 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. Fluids ...

, this may interfere with the ball check valve seating correctly.

See also