NY Well Driller key terms

A saturated geologic unit that transmits water in usable quantities to a well. Yield depends on interconnected pore space or fractures, not simply on how much water the material holds.

A low-permeability bed such as clay or unfractured bedrock that restricts water movement between aquifers. It can protect a well from surface contamination or, if breached, allow pathways between layers.

The depth to water in a well when the pump is off and the water column has recovered to equilibrium. It is measured from a fixed reference point, usually the top of the casing.

The drop in water level caused by pumping, measured as the difference between static and pumping water levels. Excessive drawdown can expose the pump intake or dewater fractures feeding the well.

The roughly conical depression in the water table or potentiometric surface surrounding a pumping well. Its shape and spread reveal aquifer transmissivity and whether nearby wells or surface water are being captured.

An imaginary surface representing the level to which water in a confined aquifer would rise under its own pressure. It guides siting decisions about flowing wells and artesian conditions.

The loose soil, sand, gravel, or clay lying above bedrock. Its thickness and permeability determine whether a well needs an outer casing and how much grout sealing is required.

A well completed in consolidated rock, drawing water mainly from fractures and bedding planes rather than intergranular pores. Yield is highly variable and difficult to predict before drilling.

A slotted or perforated section of casing set opposite a water-bearing formation to admit water while holding back formation material. Slot size is matched to the grain size of the surrounding material.

A graded envelope of clean gravel or coarse sand placed between the screen and the formation. It filters formation fines, stabilizes the borehole, and improves flow into the well.

The pipe installed in a borehole to maintain the opening, prevent collapse, and isolate the well from unwanted water or contaminants. Its diameter and wall thickness must suit pump size and depth.

Cement or bentonite slurry placed in the annulus between casing and borehole wall to block vertical water movement and contamination. Placement method and volume are critical to a proper seal.

The gap between the outside of the casing and the borehole wall. It must be filled with grout or pack material to prevent surface water, shallow groundwater, and gas from traveling down the well.

A watertight seal at the top of a well where the casing meets the ground or pitless adapter, preventing surface runoff from entering the annular space or well interior.

A vermin-proof cover fitted over the top of the well casing. It must be secured, vented where required, and sealed against insects and surface water while allowing access for measurement.

A fitting that lets the discharge pipe pass through the casing below frost depth without a pit. It keeps the wellhead above grade, improving drainage and reducing contamination risk.

A method using a rotating bit and circulating drilling fluid to cut and carry cuttings to the surface. It works in both overburden and rock and allows continuous casing and grouting control.

A percussion method in which a heavy bit is repeatedly lifted and dropped to crush rock, with a bailer removing cuttings. It gives reliable formation samples and works well in bouldery overburden.

A rotary-percussion technique using compressed air to drive a hammer bit and clear cuttings. It is fast in hard rock but can spread contaminants and needs careful control of air pressure and foam.

Mud or water circulated down the drill string to cool the bit, lift cuttings, and hold the borehole open. Its density and viscosity affect borehole stability and the quality of the finished well.

The process of removing drilling fines and mud from the screen and surrounding formation so water flows freely. Methods include surging, jetting, air lifting, and overpumping until discharge runs clear.

A controlled drawdown test that measures yield, drawdown, and recovery over time. Results estimate specific capacity, aquifer properties, and a sustainable pumping rate for the well.

Well yield per unit of drawdown, usually expressed in gallons per minute per foot. It indicates how efficiently a well produces and helps compare performance before and after rehabilitation.

Disinfection of a well by introducing a strong chlorine solution, circulating it through the system, and allowing contact time before flushing. It is done after construction, repairs, or a positive bacteria test.

A group of organisms used as an indicator of sanitary quality in well water. Their presence suggests a pathway for surface contamination and calls for inspection, disinfection, and retesting.

Laboratory analysis of well water for bacteria, nitrates, minerals, and other constituents. Testing frequency and parameters depend on local requirements and on nearby land uses.

A multistage pump and motor assembly installed below the water level in the well. It is sized to the well's yield and total head, and must be set above the pump intake clearance.

A shallow or deep well pump that uses a venturi nozzle to move water by pressure. It is common where the water level is within suction lift limits and the required capacity is modest.

A tank with a captive air charge that stores pressurized water and limits pump cycling. Its precharge and pressure switch settings must match the system's operating pressure range.

A control that starts and stops the pump at preset low and high system pressures. Correct settings protect the pump from short cycling and maintain adequate pressure at fixtures.

The volume of water delivered per unit of time, commonly gallons per minute. It is measured during yield testing and compared against the pump's rated capacity and the well's safe yield.

The permanent closure of an unused well by filling and sealing it so it cannot convey contamination between aquifers. Proper abandonment requires approved materials and documentation of the work.

The record filed after drilling that documents location, depth, casing, grout, screen, yield, and water quality. It becomes the permanent reference for future service, permitting, and abandonment.

The regulatory approval required before drilling, altering, or abandoning a well. It specifies the proposed construction and obligates the driller to file reports and meet setback and sealing rules.

The required minimum horizontal distance between a well and a contamination source such as a septic system, fuel tank, or property line. Distances are set by regulation and vary by feature type.

A safety procedure that isolates energy sources and prevents accidental startup during maintenance. It applies to pump controls, electrical panels, and any equipment that could energize while workers are exposed.

Entry into a vault, pit, or tank with limited access and possible hazardous atmosphere. It requires atmospheric testing, ventilation, an attendant, and rescue provisions before anyone enters.

A well rehabilitation technique that injects water under high pressure to open and flush fractures in bedrock. It can increase yield but must be done without damaging casing or spreading contamination.