Aquifer
An underground layer or formation that can hold and transmit water. Private wells often draw water from groundwater sources associated with aquifers, though the details vary by geology and location.
Plain-English definitions
Private well water glossary
Use this glossary to understand common private well water, testing, water quality, treatment, and rural water system terms. These definitions are educational only and do not replace testing, local guidance, or professional advice.
How to use this glossary
These definitions are intentionally simple. A term may have more precise meanings in local regulations, laboratory reports, engineering documents, well records, treatment specifications, or professional inspection reports.
Definitions
Common private well water terms
The terms below are grouped by topic so readers can connect vocabulary with the related guide sections.
Well system terms
Bored well
A well made by boring a larger-diameter hole into the ground. Bored wells are often shallower than many drilled wells and may have different protection and vulnerability considerations depending on local conditions.
Drilled well
A well made by drilling into the ground, often to a greater depth than shallow dug or bored wells. Drilled wells are common on many rural properties, but construction details, depth, yield, casing, and water quality can vary widely.
Related guide: Shallow Wells vs. Drilled Wells.
Dug well
A well that was excavated rather than drilled. Older dug wells may be large in diameter and relatively shallow. They may need careful assessment because shallow sources can be more vulnerable to surface influence.
Groundwater
Water located below the ground surface in soil, rock, fractures, or aquifers. Private wells commonly rely on groundwater, but groundwater quality can be affected by geology, land use, well construction, and nearby conditions.
Private well
A water supply used by a property or small group of properties instead of a municipal water system. A private well usually places more testing, maintenance awareness, and recordkeeping responsibility on the property owner.
Related guide: What Is a Private Well?.
Shared well
A well that serves more than one property, household, or owner. Shared wells can involve agreements, maintenance responsibilities, access questions, cost sharing, testing expectations, and local rules.
Related guide: Shared Wells and Rural Properties.
Static water level
The level at which water sits in a well when the system is not actively pumping. This is a well-record or professional measurement concept, not something most homeowners should try to assess casually.
Well cap
The cover at the top of a well casing. A proper cap helps protect the well opening from insects, debris, surface water, and other possible pathways into the well.
Related guide: Well Caps and Well Casings Explained.
Well casing
The pipe or lining that helps form and protect the well opening. Casing details can matter for well protection, construction records, local rules, and professional assessment.
Well depth
The measured or recorded depth of a well. Depth alone does not prove water quality or safety, but it can be useful background information when reviewing well records or speaking with professionals.
Related guide: Well Records, Well Depth, and Basic System Information.
Well yield
A general term for how much water a well can provide over time. Yield can matter for household use, low-water concerns, buying property, and professional assessment.
Related guide: When a Well Runs Dry or Has Low Yield.
Testing terms
Bacteria test
A test used to look for bacterial indicators in water. Bacteria testing is often one of the first topics discussed for private wells because some water safety concerns may not be visible, smelled, or tasted.
Certified laboratory
A laboratory recognized or certified for particular types of water testing under applicable rules or programs. For drinking water decisions, readers should use local guidance on appropriate laboratories and test packages.
Coliform
A group of bacteria often used as an indicator in water testing. A coliform result can suggest that contamination pathways may exist, but follow-up depends on the specific result, local guidance, and professional interpretation.
Related guide: Bacteria and Coliform in Well Water.
E. coli
A specific type of bacteria that may be included in drinking water testing. Its presence can raise serious concern and should be handled according to laboratory, local authority, and qualified professional guidance.
Lab report
A document from a laboratory showing test results. Lab reports may include measured values, units, detection limits, references, comments, or flags. Interpretation should follow local guidance and qualified advice where needed.
Related guide: How to Read a Well Water Test Report.
Nitrates
A water quality concern that may be associated with agriculture, septic influence, fertilizer, soil conditions, or other environmental sources. Nitrate results should be interpreted using laboratory and local health guidance.
Related guide: Nitrates in Well Water.
Parameter
A specific item being tested or measured, such as coliform, nitrate, pH, hardness, iron, or another water quality factor. Different test packages include different parameters.
Potable water
Water considered suitable for drinking under applicable standards or guidance. Whether water is potable cannot be determined from appearance alone and may require appropriate testing and local interpretation.
Sampling bottle
A container provided or specified for collecting a water sample. Laboratories may require specific bottles, preservatives, handling steps, timing, and chain-of-custody procedures depending on the test.
Well water testing
Testing used to understand water quality, safety indicators, and treatment-related characteristics. Well water should be tested when and as needed to help ensure it is safe to drink.
Related guide: When Should You Test Well Water?.
Water quality terms
Cloudy water
Water that appears hazy, milky, or unclear. Cloudiness can have several causes, including air, sediment, minerals, disturbance, plumbing conditions, or other issues. It should not be used by itself as a safety test.
Related guide: Cloudy Well Water.
Hard water
Water with higher levels of minerals such as calcium and magnesium. Hard water can affect scale, soap performance, fixtures, appliances, and comfort, but hardness alone is not a complete drinking water safety assessment.
Related guide: Hard Water From a Well.
Hydrogen sulfide
A gas commonly associated with a rotten-egg or sulfur-like smell in water. Odour sources can vary, and smell alone should not be used to choose treatment or assess water safety.
Related guide: Sulfur Smell in Well Water.
Iron
A mineral that can affect well water taste, colour, staining, fixtures, laundry, and treatment decisions. The form and amount of iron matter when discussing treatment options.
Related guide: Iron in Well Water.
Manganese
A naturally occurring element that may contribute to dark staining or water quality concerns in some wells. Like other water quality factors, it should be interpreted through appropriate testing and local guidance.
pH
A measure of how acidic or basic water is. pH can affect corrosion, taste, treatment choices, and how water interacts with plumbing or fixtures.
Sediment
Particles visible or suspended in water. Sediment may come from the well, plumbing, disturbance, filters, or other sources. Persistent or sudden sediment should be understood with testing or professional review where needed.
Related guide: Sediment in Well Water.
Staining
Discolouration left on fixtures, laundry, sinks, toilets, tubs, or surfaces. Staining may be associated with iron, manganese, hardness, acidity, or other water chemistry issues.
Related guide: Staining From Well Water.
Total dissolved solids
A broad measure of dissolved materials in water. It can be relevant to taste, treatment discussion, and general water chemistry, but it does not identify every possible health or safety concern by itself.
Turbidity
A measure related to water clarity and suspended particles. Turbidity can matter for water appearance, treatment performance, and interpretation of some water quality concerns.
Treatment terms
Activated carbon filter
A type of filter often discussed for taste, odour, and certain chemical-related concerns. Its usefulness depends on water chemistry, filter design, maintenance, and the specific issue being addressed.
Cartridge filter
A replaceable filter element used in some household water systems. Cartridge filters vary by purpose and rating. A sediment cartridge, for example, is not the same as a full treatment solution for all water concerns.
Filter
A general term for equipment intended to remove or reduce certain materials from water. Different filters do different things, so treatment should be based on testing and professional guidance.
Related guide: Filters for Well Water.
Point-of-entry treatment
Treatment installed where water enters the home, so it can affect water throughout much of the household. The right approach depends on test results, system design, household needs, and professional advice.
Point-of-use treatment
Treatment installed at a specific tap or location, such as under a sink. It may be used for targeted purposes, but it does not necessarily treat every water outlet in the home.
Reverse osmosis
A treatment process that uses a membrane to reduce certain dissolved substances. Reverse osmosis systems vary, and their suitability depends on water chemistry, goals, maintenance, and professional guidance.
UV treatment
A treatment concept that uses ultraviolet light in a properly designed system to address certain microbial concerns. UV performance can depend on water clarity, equipment sizing, maintenance, lamp condition, and installation quality.
Related guide: UV Treatment for Well Water.
Water softener
Equipment commonly used to address hardness minerals. A softener may help with scale and comfort issues, but it is not a general drinking-water safety system.
Related guide: Water Softeners for Well Water.
Treatment professional
A person or company that assesses water treatment needs and recommends, installs, services, or maintains treatment equipment. Good treatment decisions should be based on proper testing, clear goals, and local context.
Related guide: Choosing Water Treatment Professionals.
Property and responsibility terms
Local health authority
A public body or agency that may provide guidance related to drinking water safety, testing, health concerns, or local requirements. The exact name and role vary by location.
Related guide: Local Health Authorities and Well Water.
Private well responsibility
The owner’s role in arranging testing, understanding records, protecting the well area, responding to changes, and getting qualified help when needed. Responsibilities can vary by location and property type.
Related guide: Well Water Responsibility for Homeowners.
Rural property
A property outside many municipal service areas. Rural properties may use private wells, septic systems, propane, longer driveways, private roads, drainage features, or other systems that require owner awareness.
Related guide: Well Water and Rural Properties.
Septic system
A private wastewater system often found on rural properties. A septic system is separate from a private well, but the two systems can matter together because property layout, separation, drainage, and local rules may affect ownership decisions.
Related guide: Well and Septic Systems on Rural Property. For septic-specific topics, see SepticSystemGuide.org.
Well inspection
A review of a well or related system by a qualified person, depending on the scope. Inspection may involve location, visible components, records, performance, and recommendations for further testing or professional review.
Related guide: Well Inspections Explained.
Well records
Documents or information about a well, which may include age, depth, construction details, contractor information, yield, repairs, testing history, treatment equipment, or inspection notes.
Related guide: Keeping Records for a Private Well.
Well setback or separation distance
A required or recommended distance between a well and possible sources of contamination, structures, septic components, property features, or land uses. Requirements vary by location and should be checked locally.
Definitions are not safety decisions
Knowing a term is helpful, but it does not determine whether water is safe, whether a well is properly built, whether treatment is suitable, or whether a property is safe to buy. Use certified laboratories, local authorities, and qualified professionals for property-specific decisions.