New Hampshire Water Well Association




The word artesian is commonly used to refer to modern drilled wells, but a true positive pressure artesian well is one where the water is under pressure in the ground (due to geologic conditions) and flows above the ground surface.


A bored well is constructed using an earth moving auger and is designed to reach water in the loose, unconsolidated material above the bedrock.



A water-bearing hole in ground (typically 6" in diameter for residential wells) that is drilled using a bit and continues down through bedrock to reach water bearing fractures or under ground aquifers. The well will include casing to prevent the entrance of surface water or debris from entering the well.

Driven or Point Well

A driven well is typically less than 50' deep, used in an area where the sand or gravel above bedrock holds water which can be accessed by a special pipe with slots or holes and a suction pump.


Dug Well or Shallow Well

A water-bearing hole in the ground surrounded by a concrete tile, stones or brick. Generally less than 25 feet deep. Dug wells can provide reliable water supplies, but are more prone to seasonal fluctuations in both quantity and quality of water.


Gravel Pack

A method where gravel is placed around the outside a well screen on a well to prevent sand from entering the well and clogging the screen or holes.


Pounded (or Cable Tool)

With this method of well drilling a heavy bit is dropped repeatedly into the well hole, breaking up the material which is then bailed out of the well. This method is done using a cable tool and is also referred to as percussion.

Hand Pump

A piston style pump operated by hand via a handle mounted to the pump.

Single Pipe or Shallow Well Jet Pump

A centrifugal style pump aided by a nozzle and venturi. Used for shallow well applications with a water level of no more than about 25’.

Two Pipe Jet Pump

A two-pipe or deep well jet pump works with the same principle of a shallow well jet except the nozzle and venturi are moved into the well giving it a useable depth of about 200’. This is old technology which is difficult to troubleshoot and service.

Piston Pump (also known as the one lunger)

Positive displacement pump used in shallow well applications. Operates with a piston and valves. This is your grandfather's pump.


A centrifugal style pump using multiple (5-30) small diameter impellers driven by a waterproof submersible motor installed in the well. These pumps have the capability to pump water from over 1000’. These are the most common type of domestic pumps sold in this area, outselling other styles by upwards of 1000 to 1.


VFD (Variable Frequency Drive)

A variable frequency drive pump uses an electronic controller that is able to match motor speed to the need. This is an alternative to standard pumps that are either on or off. Pressure can be maintained at a much tighter tolerance within the system, without the use of a pressure tank. This results in energy savings as well as improved average pressure and flow.

Water Well Contractor

A water well contractor license is required of any entity or individual engaged in well construction or decommissioning. Water well construction means any method, procedure or operation to obtain water from a well including drilling, digging, well development (including hydro-fracturing or other methods), for any purpose or use. Licenses are issued by the New Hampshire Water Well Board to contractors and are specific to constrution type (rotary, technical, wash well / point, cable tool, point well, dug well). Business entities are required to register with the Department of State. There are approximately 200 licensed contractors in the State of NH. NH Statute: RSA 482:b. NH Code of Administrative Rules: We100-We1000.


Pump Installer

A pump installer license is required of any entity or individual engaged in water well pump installation. Licensed plumber and electricians are authorized to repair and service water well pumps, however, they must obtain a pump installer license to install or replace a pump. The NH Water Well Board issues two categories of licenses, for domestic (up to three horsepower) and commercial, industrial and municipal pump installation (any horsepower). Business entities are required to register with the Department of State. There are approximately 300 Licensed Pump Installers in NH, with a term of One Year. NH Statute RSA 482:b, NH Code of Administrative Rules: We 100-We 1000.


NH Water Well Board

For additional information contact: NH Water Well Board, 29 Hazen Drive, PO Box 95, Concord, NH 03302-0095. 603-271-1974.


A sub-surface geologic formation that contains ground water in sufficient quantity to be used or have the potential to be used for drinking water supply. (American Ground Water Trust)


The process where the solids collected in a water filter are removed by reversing the flow of water through the filter at higher speed and volume. The filtration media lofts during this reversal of water flow, and collected particles are flushed to drain.



Metal or plastic pipe that extends into the bedrock of a drilled well to prevent surface water and debris from entering the well.


Drive Shoe

A steel collar with a cutting edge that is attached to the lower end of well casing to protect the casing as it is driven into the well hole. This is required by code in NH.


Filter, Backwashing

A backwashing filter usually consists of a fiberglass tank with a special media inside, and a control valve. The media is chosen for its ability to remove particles of a certain size or nature from water. The control valve controls the backwash of the filter which is the cleaning process where the filtered particles are flushed out of the media and sent to drain. Click here to see a schematic of a Backwashing Filter.


Filter, Cartridge

A cartridge filter is a disposable device used to separate solids from water. The cartridge element is set into a housing. Cartridge filters are available in a wide variety of sizes, filtration abilities (usually measured in micron filtration capability) and materials, depending upon the nature of the solids to be removed.



Geothermal refers to the heat that is stored in the earth. The temperature of ground water can be transferred to a heating or cooling system within a building, greatly reducing energy consumption..


Ground Source Heat Pump

A ground source heat pump uses the relatively constant temperature of ground water via an electrically powered system that cycles ground water through a heat pump to extract the warmth or relative coolness from the ground water.



When a well is drilled, the hole is larger than the casing. The space between the casing and the ground is called the annular space. An impervious material is used to fill this space to prevent surface water from migrating into the well. Grout is used to fill this space, an impervious material such as cement or a volcanic clay called bentonite. Grouting is required by code in certain applications.


Hydro Fracture

A process for increasing the yield of a well by applying water under pressure into the well, therefore opening up fractures.


Pitless Adaptor

A fitting that is attached to the well casing to provide a sanitary and frost-proof seal between the casing and the water line running to the home. This device protects the water from freezing and permits convenient access to the well and well components without having to dig around the well. The adaptor is connected to the well casing below the frost line. Water from the well is diverted horizontally at the adaptor where it travels in piping under ground, below the frost line, to the home.


Pressure Drop

Measures the amount of pressure per square inch (PSI) that is lost due to friction or height as water passes through pipes and water treatment materials.


Pressure Tank

A closed tank (usually fiberglass or metal) holding water under pressure which is provided by compressed air. Modern residential pressure tanks use a rubber bladder which separates the air and water and prevents the air from mixing in the water and disappearing. The pressure tank's main function is to prevent the pump from going on and off excessively. Its secondary purpose is to provide some water stored under pressure. Without an air charged pressure tank, pressure in the system drops immediately when any amount of water is used, therefore shortening the life of the well pump.


Pump Stages

A pump stage is the portion of a centrifugal pump consisting of one impeller and its associated components. Most centrifugal pumps are single-stage pumps containing only one impeller. A pump containing seven impellers within a single casing would be referred to as a seven stage pump or as a multi-stage pump.


Recovery Rate

This rate, usually noted in gallons per minute, refers to the flow of water returning to the well as water is removed from the well through pumping.



The process where a water softener or filter cleans itself and freshens up the media for further use. A water softener is regenerated using salt (sodium chloride) or potassium (potassium chloride). A manganese greensand filter regenerates using potassium permanganate.


Reverse Osmosis

A membrane technology where a specially manufactured semi-permeable membrane is used to separate water from the contaminants dissolved in the water. Contaminants such as sodium, arsenic, nistrates, and lead can be separated from the water using this method, and are flushed to drain.



A water softener uses a specially manufactured plastic material, called resin, to attract dissolved calcium, magnesium, iron or manganese from a stream of water as it passes through the water softener tank. The minerals are attracted to the resin due to their electro static charge and are held in the tank until the regeneration is triggered by the control valve. During the regeneration process a solution of sodium or potassium is used to force the minerals off the resin beads and flush them to drain. The resin beads are then "recharged" and ready for another cycle. Click here to see a schematic of a Water Softener.


Torque Arrestor

A fitting that is clamped onto the drop pipe of a submersible pump, to hold the pump snugly centered in the well casing. A torque arrestor also is used to keep the pump centered in the well, preventing the pump from rubbing against the well casing which could lead to motor cooling problems or hydraulic imbalances. A pump hanging on a plastic pipe without torque arrestors will tend to move around resulting in abrasion to electric cable. The torque arrestor is required by code.

Ultra Violet

A sterilization process where a stream of water is exposed to a specific portion of the light spectrum that is able to disrupt the DNA of bacteria, rendering them unable to reproduce and therefore harmless. The UV light is installed with a protective quartz sleeve, and the light and sleeve are usually installed in a stainless steel housing.


Variable Frequency Drive

A variable frequency drive pump uses an electronic controller that is able to match motor speed to the need. This is an alternative to standard pumps that are either on or off. Pressure can be maintained at a much tighter tolerance within the system, without the use of a large pressure tank. This results in energy savings as well as improved average pressure and flow.


Well Abandonment

An abandoned well must be filled with an impervious material to prevent the well from becoming a pathway for contaminants to travel.


Well Disinfection

A process where bacteria are killed in a well using chlorine. This procedure is done when a well is first introduced to service, or after service work is performed on the pumping system, and is required by code. Also known as "shocking the well" because a strong bleach concentration is used to assure full sanitization of the well and piping.