MA Well Driller key terms

The land area whose groundwater and surface water can eventually reach a public water supply well under pumping conditions. Massachusetts uses it to set wellhead protection review areas and land-use controls.

The regulated surface and subsurface area around a public well where activities are managed to prevent contamination. Delineation uses hydrogeologic mapping, pumping rates, and travel-time criteria rather than a fixed radius alone.

A saturated geologic formation that can store and transmit water in usable quantities to a well. Sand and gravel aquifers, bedrock fracture zones, and some tills differ greatly in yield and vulnerability.

A low-permeability bed, such as clay or dense till, that restricts vertical water movement and separates aquifers. It influences whether a well is confined or unconfined and affects contamination pathways.

Unconsolidated material, including soil, sand, gravel, and till, lying above bedrock. Overburden wells require casing and grout to isolate shallow water and prevent downhole migration of contaminants.

A well completed in consolidated rock, typically drawing water from fractures rather than pores. Yield depends on intersecting water-bearing fractures, which are difficult to predict from surface geology alone.

A well that penetrates a confined aquifer where water level rises above the top of the aquifer, sometimes flowing at the surface. Flowing artesian conditions require control measures to prevent uncontrolled discharge and cross-connection risks.

The imaginary level to which water would rise in a tightly cased well screened in a confined aquifer. It indicates hydraulic head and helps determine whether artesian flow or upward leakage is possible.

The water level in a well when the pump is off and the water has stabilized. It is recorded at completion and used to track long-term aquifer trends and pumping effects.

The stabilized water level in a well while the pump is operating. The difference between static and pumping levels defines drawdown and helps set pump depth and screen position.

The drop in water level caused by pumping, measured as static level minus pumping level. Excessive drawdown can dewater screens, reduce yield, or induce poor-quality water from adjacent units.

The roughly conical depression in the water table or piezometric surface surrounding a pumping well. Its shape and extent help define the zone of contribution and the reach of pumping influence.

The change in hydraulic head per unit distance in the direction of groundwater flow. It controls flow direction and velocity, which matter for contaminant travel time and wellhead protection boundaries.

Well yield expressed per unit of drawdown, typically gallons per minute per foot. It summarizes well efficiency and aquifer transmissivity and helps compare wells and design pumping rates.

The rate at which water moves through a unit-width vertical strip of aquifer under a unit hydraulic gradient. It combines hydraulic conductivity and saturated thickness and supports yield and impact analysis.

A controlled pumping or bailing test that measures yield, drawdown, and recovery to characterize well performance. Results guide pump sizing, screen setting, and whether the well meets intended demand.

The pipe installed in a borehole to maintain the opening, prevent collapse, and isolate the well from surrounding material. Material, wall thickness, and proper seating must suit the well type and water chemistry.

A slotted or perforated section installed opposite a water-producing formation to admit water while holding back sand and gravel. Slot size is matched to formation grain size to reduce sediment entry.

Filter material placed between the well screen and borehole wall in coarse or uniform sand and gravel formations. Properly sized pack material improves yield and reduces pumping of fines.

The process of removing drilling mud, fines, and other material from the formation near a well to improve flow. Methods include surging, jetting, bailing, and controlled pumping until water clears.

A low-permeability material, such as neat cement or bentonite, placed in the annular space to seal a well against surface water and cross-aquifer movement. Placement method and volume must be verifiable.

The gap between the borehole wall and the casing or between nested casings. It must be filled with suitable grout or filter material to prevent vertical migration of water and contaminants.

A grouting technique in which grout is pumped through a pipe discharging near the bottom of the annular space. It displaces water upward and avoids voids that can occur from free-fall placement.

The watertight connection at the top of a well between the casing and the pump or cap assembly. It blocks surface water, insects, and debris from entering and is essential to wellhead protection.

A well no longer used for its intended purpose or incapable of being used. Massachusetts requires proper sealing with approved materials and reporting so it cannot act as a conduit for contamination.

The permanent closure of a well by removing obstructions as needed, filling the borehole with approved sealing material, and documenting the work. It protects groundwater and removes physical hazards.

Massachusetts Department of Environmental Protection review and approval of a proposed public water supply source before use. It evaluates yield, water quality, hydrogeologic setting, and protection from contamination.

Local or state authorization required before drilling or deepening a well. Applications typically identify the owner, site, proposed depth and construction, and set conditions the driller must follow.

The required record submitted after well construction summarizing location, depth, casing, grout, screen, yield, and water quality. Accurate reports support permitting, public records, and future maintenance.

A detailed record of the geologic materials, depths, and construction features encountered in a borehole. It guides screen and casing decisions and provides evidence of proper sealing and abandonment.

Laboratory analysis of well water for indicators such as bacteria, nitrate, arsenic, and other contaminants. Sampling procedures and certified laboratories are specified to ensure defensible results and appropriate response.

The enforceable maximum allowable concentration of a contaminant in public drinking water. Results above an MCL trigger treatment, blending, source restriction, or public notice obligations.

The actions taken when well water fails a standard, such as resampling, investigating the source, treating, or taking the well out of service. Response must match the contaminant and regulatory requirements.

Treatment intended to inactivate pathogens in a well, pump, or distribution system, often using chlorine or other approved agents. Proper contact time and concentration are needed, followed by verification sampling.

A physical link between a potable water system and a nonpotable source that could allow backflow. Well systems need backflow prevention and air gaps to protect the aquifer and drinking water.

The depth at which a submersible or other pump is installed in the well. It must stay submerged during worst-case drawdown while avoiding screen or bottom disturbance.

An accumulation of sand or formation material in a borehole or on top of a pump that can stick tools or block flow. It may indicate screen or gravel pack failure and requires cleaning and evaluation.

Temporary measures such as silt fence, straw bales, and stabilized access used during drilling to keep soil and turbid water out of wetlands and surface waters. They are part of site restoration obligations.

Cleanup and stabilization of the drilling site after work ends, including removal of cuttings and debris, regrading, and revegetation. It protects water resources and leaves the property in acceptable condition.