Definition for Underground Utility Terms A-C

Abandonment: The process of decommissioning and sealing off an underground utility line or structure that is no longer in use. Abandonment

Above Ground Marker: A visible marker or sign installed above the ground to indicate the presence and location of underground utility lines, assisting in their identification and protection. Above Ground Marker

Abutment: A support structure or wall used to resist lateral pressure from a trench or excavation.Abutment

Access Chamber: An underground chamber providing access to multiple utility lines for maintenance and repairs. Access Chamber

Access Shaft: An underground vertical shaft or passage that provides access to a utility tunnel, sewer system, or underground infrastructure for maintenance, inspection, or repairs. Access Shaft

Air Gap: A physical separation or vertical distance maintained between an underground utility pipe and a potential source of contamination, ensuring the prevention of cross-connections. Air Gap

Air Rotary Drilling: Air rotary drilling is a drilling technique used in various industries, including mining, oil and gas exploration, and geothermal energy extraction. Air Rotary Drilling

Air Release Valve: A valve installed in underground water or wastewater pipelines to automatically release air pockets or trapped gases, ensuring optimal system performance and preventing damage. Air Release Valve

Air Spade: A tool that uses compressed air to remove soil around utility lines without causing damage. Air Spade

Air Sparging: A remediation technique that involves injecting air or gases into the subsurface to remove volatile organic compounds (VOCs) or contaminants from underground water or soil. Air Sparging

Air Valve: A device installed in underground water pipelines to release trapped air pockets and prevent the formation of airlocks, promoting efficient flow and preventing pipe damage. Air Valve

Anchor Block: A heavy concrete or steel block used to anchor or secure underground utility structures, such as tanks, manholes, or equipment, against uplift or movement. Anchor Block

Anticorrosion Coating: A protective coating applied to metallic pipes or conduits to prevent corrosion caused by exposure to moisture or other corrosive elements. Anticorrosion Coating

Anti-siphon Valve: A valve installed in underground irrigation systems to prevent backflow and contamination of the potable water supply, maintaining water quality standards. Anti-siphon Valve

Aquifer Storage and Recovery (ASR): A method of storing excess water underground in natural or constructed aquifers during periods of surplus, for later extraction and use during dry seasons or droughts. Aquifer Storage and Recovery (ASR)

As-Built Drawings: Drawings that document the precise location, type, and configuration of underground utilities after they have been installed. As-Built Drawings

Asphalting: The process of restoring or repairing the surface of a road or pavement after underground utility work. Asphalting

Asset Management System: A software or system used to track, monitor, and manage underground utility assets, including inventory, maintenance, and lifecycle management. Asset Management System

Asset Management: The systematic approach of managing and maintaining underground utility assets to optimize their lifespan and performance. Asset Management

Asset Mapping: The process of creating detailed inventories and digital records of underground utility assets, including their location, condition, and operational information for efficient management. Asset Mapping

Auger Boring: A trenchless method of underground utility installation that uses a rotating auger to create a bore while simultaneously removing soil or other material. Auger Boring

Automated Meter Reading (AMR): A system that collects and transmits utility meter data from underground meters, such as water or gas meters, electronically, enabling accurate billing and consumption monitoring. Automated Meter Reading (AMR)

Backfill Compaction: The process of compacting the backfill material around underground utilities to improve soil density, stability, and load-bearing capacity, reducing settlement and potential damage. Backfill Compaction

Backfill Material: The material used to refill and compact the space around underground utility pipes or structures after excavation, providing support, stability, and protection. Backfill Material

Backfill: The process of refilling the trench with excavated materials or suitable fill material after the utility installation is complete. Backfill

Backflow Preventer: A device installed in water supply systems to prevent the reverse flow of contaminated water into the potable water system. Backflow Preventer

Backhoe: A heavy-duty excavation machine with a digging bucket mounted on the back, used for digging trenches and excavating soil in underground utility work. Backhoe

Ballasting: The process of adding weight or ballast to underground structures or pipes to provide stability or prevent flotation. Ballasting

Bell and Spigot Joint: A type of connection between pipes where one end (spigot) is inserted into a slightly larger end (bell) and sealed with a gasket or joint material. Bell and Spigot Joint

Blowdown Valve: A valve used to release excess pressure or remove sediment from a pipeline or vessel. Blowdown Valve

Blow-off Valve: A valve used to release excess pressure or drain water from a pipeline. Blow-off Valve

Borehole: A deep, narrow hole drilled into the ground to explore subsurface conditions or extract groundwater. Borehole

Boring Machine: A machine used to create horizontal underground tunnels or bores for the installation of utilities without open-cut excavation. Boring Machine

Boring: A method of installing underground utilities by creating a tunnel or hole using specialized equipment. Boring

Bulkhead: A structure or wall constructed in an underground utility system to separate different areas or sections, often used to control the flow of fluids or prevent the spread of contaminants. Bulk Head

Bypass Pumping: The temporary installation of pumps and pipes to redirect or manage the flow of liquids during utility repairs or maintenance. Bypass Pumping

Bypass Valve: A valve used to divert or bypass the flow of fluids in a pipeline during maintenance or emergency situations. Bypass Valve

Cable Duct: An underground conduit or channel designed to house and protect electrical or communication cables, facilitating their installation, organization, and maintenance. Cable Duct

Cable Fault Locator: A specialized device used to locate and pinpoint faults, breaks, or damage in underground utility cables, enabling efficient repair and maintenance. Cable Fault Locator

Cable Plow: A cable plow, also known as a vibratory plow or a cable trencher, is a specialized construction equipment used to install or bury underground cables, such as electrical, telecommunications, or fiber optic cables. Cable Plow

Cable Puller: A device or machine used to pull or tension electrical cables or wires through underground conduits. Cable Puller

Cable Tray: A metal or plastic support system used to hold and route underground electrical cables or communication wires, ensuring organized and safe installation. Cable Tray

Caisson: A watertight chamber or structure used for underwater construction, inspection, or repair of utility infrastructure. Caissson

Call Before You Dig: A service provided by utility companies or agencies where contractors or individuals are required to notify them before digging to avoid damaging underground utilities. Call Before You Dig

Carrier Gas: In gas utility systems, a non-reactive gas (such as nitrogen) used to transport or push another gas through the pipeline. Learn More…Carrier Gas

Carrier Pipe: The inner pipe or conduit that carries the primary fluid or material within an underground utility system. Carrier Pipe

Casing Pipe: A protective pipe installed around another pipe or conduit for added strength or to prevent damage. Casing Pipe

Catch Basin: An underground structure or chamber designed to collect and temporarily store stormwater runoff, removing sediment and debris before it enters the drainage system. Catch Basin

Catchment Area: The area or region from which stormwater runoff is collected and directed to underground drainage systems or facilities, typically defined by topography or land use. Casing Pipe

Catchment Basin: 1. A catchment basin, also known as a drainage basin or watershed, is an area of land that collects and drains water from precipitation, such as rainfall or snowmelt, into a common outlet, such as a river, lake, or ocean. 2. A subsurface or underground basin designed to collect and store stormwater runoff, allowing for gradual infiltration or controlled release. Catchment Basin

Catheterization: The process of inserting a flexible tube or catheter into a pipeline to perform maintenance, inspection, or repair activities. Catheterization

Cathodic Disbondment: The separation or detachment of a protective coating from underground metal pipes or structures due to electrochemical processes, leading to corrosion and degradation. Cathodic Disbondment

Cathodic Protection Rectifier: A device used to supply a direct electrical current to underground metallic structures, such as pipelines or tanks, to prevent corrosion. Cathodic Protection Rectifier

Cathodic Protection System: A system installed in underground metallic structures or pipelines to prevent corrosion by applying a protective electrical current or voltage to the metal surface. Cathodic Protection System

Cathodic Protection: A technique used to protect underground metal pipes or structures from corrosion by applying a protective electrical current or sacrificial anodes, extending their service life. Cathodic Protection

Cavitation: Cavitation is a phenomenon that occurs in fluid dynamics when the local pressure of a liquid drops below its vapor pressure, resulting in the formation of small vapor-filled cavities or bubbles within the fluid. Cavitation

Cavity Wall: A double-wall construction technique used in underground utility structures, such as manholes or chambers, to provide insulation, strength, and protection against external forces. Cavity Wall

CCTV Inspection: The use of Closed-Circuit Television (CCTV) cameras to visually inspect the condition and integrity of underground utility pipelines or structures, identifying defects, blockages, or leaks. CCTV Inspection

Chemical Injection System: A system used in underground utility operations to inject chemicals or additives, such as corrosion inhibitors or disinfectants, into water or wastewater streams. Chemical Injection System

Chloramine: A disinfectant formed by combining chlorine and ammonia, commonly used in water treatment to maintain water quality. Chloramine

Chlorination: The process of adding chlorine or disinfectants to water or wastewater systems to kill bacteria and ensure water quality. Chlorination

CI Casting: CI casting refers to “Cast Iron casting,” which is a manufacturing process used to produce cast iron components or parts. CI Casting

CIPP Lining: Cured-in-place pipe lining, a trenchless rehabilitation method that involves inserting a flexible liner into existing underground pipes and curing it in place to create a new structural lining. CIPP Lining

Cleanout: An access point in a sewer or drainage system used for clearing blockages or performing maintenance. Cleanout

CMP (Corrugated Metal Pipe): A type of pipe made from corrugated metal sheets, commonly used for drainage systems and culverts. CMP Corrugated Metal Pipe Corrugated Metal Pipe (CMP)

Coarse Screening: The initial stage in wastewater treatment where large debris, such as rocks, sticks, or trash, are removed to prevent damage to downstream equipment. Coarse Screening

Coating Thickness Gauge: A device used to measure the thickness of protective coatings applied to underground utility pipes or structures. Coating Thickness Gauge

Coaxial Cable: A type of cable consisting of an inner conductor surrounded by a tubular insulating layer and a metallic shield, commonly used for telecommunications and cable TV. Coaxial Cable

Communication Conduit: An underground conduit or duct used to house and protect communication cables, such as fiber optics, facilitating the transmission of data or signals. Communication Conduit

Compaction Testing: The process of evaluating the density and compaction of underground soils using specialized equipment, ensuring adequate support and stability for utility installations.

Compression Ring: It is a type of sealing mechanism that ensures a secure and watertight connection between pipes or pipe fittings. Compression Ring

Composite Manhole Cover: A lightweight and durable alternative to traditional cast iron manhole covers, typically made of materials like fiberglass or composite resins, offering resistance to corrosion and theft. Composite Manhole Cover

Concrete Encasement: The process of surrounding underground utility pipes or structures with a layer of concrete for added protection, strength, or corrosion resistance. Concrete Encasement

Concrete Scanning: The use of ground-penetrating radar (GPR) or other technologies to locate and map the position of rebar, post-tension cables, or other subsurface features in concrete structures or slabs. Concrete Scanning

Conductor: A wire or cable used for carrying electrical current. Conductor

Conduit Bender: A tool or device used to create bends or curves in electrical conduit for routing cables in underground utility systems. Conduit Bender Conduit Bender

Conduit: A pipe or tube used for protecting and routing electrical or telecommunications cables. Conduit

Confined Space Entry: The process of entering and working in underground utility spaces that have limited access, potentially posing risks to worker safety. Confined Space Entry

Contour Map: A map that depicts the elevation and shape of the land surface, often used in underground utility planning and design. Contour Map. Contour Map

Control Room: An underground facility or room equipped with control panels, monitors, and equipment for monitoring and operating underground utility systems, such as water treatment plants or pumping stations. Control Room

Corrosion Inhibitor: A chemical substance applied to underground metal pipes or structures to prevent or slow down the corrosion process, extending their lifespan and maintaining structural integrity. Corrosion Inhibitor

Corrosion Protection: Techniques and materials used to prevent or slow down the degradation of underground utilities due to chemical reactions or environmental factors. Corrosion Protection

Corrugated Metal Pipe: A pipe made of corrugated metal sheets or strips, often galvanized or coated, used in underground stormwater management systems, culverts, or drainage applications. Corrugated Metal Pipe

Coupling Gasket: A rubber or elastomeric gasket used in pipe couplings to provide a watertight and secure connection. Coupling Gasket

Coupling: A fitting used to join two sections of pipe or conduit together to create a continuous pipeline. Coupling

Cross Boring Detection: The identification and mitigation of cross bore situations, where underground utility lines unintentionally intersect with other utilities, such as gas lines intersecting with sewer pipes. Cross Boring Detection

Cross Boring: The unintended intersection of underground utility lines, such as gas or sewer lines, during the installation of new utilities using trenchless methods. Cross Boring

Cross-Connection: An unwanted or unauthorized connection between a potable water supply and a non-potable source, posing a risk of contamination. Cross Connection

Curb Box: An underground access point or box used to provide access to utility shut-off valves or controls, typically located at the edge of a roadway or property. Curb Box

Curb Stop: A valve located near the curb or property line that allows the control of water flow to an individual property. Curb Stop

Cut-and-Cover Method: A construction technique for underground utilities that involves excavating a trench, installing utilities, and then covering the trench with soil or other materials. Cut-and-Cover Method 

Cut-off Wall: A vertical underground barrier constructed to prevent the flow of water or contaminants, often made of impermeable materials like concrete or bentonite, used in applications such as groundwater control or containment. Cut-off Wall