Underground Utility Contractors Industry Terminology
APWA Color Code
Standardized surface-marking colors used to identify underground utility types: red-electric, yellow-gas/oil/steam, orange-communications, blue-potable water, green-sewer/drain, purple-reuse, pink-survey, white-proposed excavation.
Use APWA colors when marking the site before potholing.; The telecom line should be marked orange within the work limits.; White-line the proposed trench per APWA to request accurate locates.
As-Built Drawings
Record drawings that show the exact dimensions, locations, elevations, and materials of the utilities as installed, including deviations from the design plans.
Submit as-builts with GPS shots on all valve boxes before final acceptance.; The inspector requested as-built invert elevations at each manhole.; Redline the field changes daily to expedite the as-built set.
Auger Boring
A trenchless method that installs steel casing by rotating an auger from a jacking pit while simultaneously advancing the casing; typically used for road/rail crossings.
We’ll auger bore a 36-inch casing under the highway at Sta. 22+50.; Check line and grade in the jacking pit every 5 feet.; Railroad requires casing installed by auger bore with monitoring for settlement.
Best Management Practices (BMPs)
Practical measures to prevent erosion, sedimentation, and pollution during construction (e.g., silt fence, inlet protection, stabilized entrances, street sweeping).
Install BMPs before starting any soil disturbance.; Maintain inlet protection after each rain event.; Update the BMP map in the SWPPP binder weekly.
Bid Bond
A surety bond submitted with a bid guaranteeing that the bidder will enter into the contract and provide required performance/payment bonds if awarded.
The city requires a 10% bid bond for all utility packages.; The bid is nonresponsive without the bond.; Confirm the surety is AM Best A- or better on the bid bond.
Bore and Jack
A trenchless technique where a pipe or casing is jacked through the ground while soil is removed (often by auger). Used to avoid surface disruption.
The gas main crossing will be installed by bore and jack to avoid lane closures.; Set up the jacking frame and thrust block per the engineer’s detail.; Verify carrier pipe spacers within the jacked casing.
CCTV Inspection
Closed-circuit television camera inspection of sewers or storm drains to assess condition, verify cleaning, or support acceptance testing.
Perform post-lining CCTV before final payment.; The CCTV showed root intrusion at MH 4-5.; Provide PACP-coded CCTV logs with the video.
Change Order
A formal modification to the contract scope, price, and/or time, typically initiated by the owner, engineer, or contractor due to unforeseen conditions or design changes.
Submit a change order for extra rock excavation.; The CO includes cost, schedule impact, and supporting backup.; We need owner approval before proceeding under this change.
Compaction
Densification of backfill to a specified percentage of maximum dry density (e.g., 95% of ASTM D1557) to control settlement and support loads.
Achieve 95% compaction to subgrade before paving.; Take a nuclear density test every 150 feet of trench.; Rework lifts that fail compaction.
Confined Space Entry
OSHA-regulated entry into spaces not designed for continuous occupancy with limited entry/exit (e.g., manholes, vaults). May be permit-required due to hazards.
Treat this manhole as a permit-required confined space.; Test oxygen levels and ventilate before entry.; Attendant and retrieval system must be in place.
Damage Prevention
Policies and practices to avoid utility strikes: call 811, white-line, pothole, respect tolerance zones, use spotters, and follow state statutes.
Our damage-prevention plan requires daylighting all marked crossings.; The crew will use a spotter within the tolerance zone.; Track near-misses to improve our damage prevention program.
Dewatering
Lowering groundwater or removing stormwater to create dry, stable excavation conditions (e.g., well points, sump pumps, deep wells).
Install a well point system along the sewer trench.; Discharge dewatering effluent to a permitted location with filtration.; Maintain pumps 24/7 during the tie-in.
Directional Drilling (HDD)
A steerable trenchless method to install utilities along a designed bore path; involves pilot bore, reaming, and product pullback using drilling fluid.
Monitor returns to prevent a frac-out near the creek.; Use a wireline locator for the pilot bore.; Submit the HDD plan with drill fluid management.
Duct Bank
A group of conduits installed together, often encased in concrete with spacers and warning tape, used for electric or communications.
Pour the concrete-encased duct bank per the detail.; Pull a mule tape in each duct for cable installation.; Maintain minimum cover and separation per utility standards.
Easement
A legal right to use another’s land for a specific purpose (e.g., install and maintain a pipeline); may be public or private, temporary or permanent.
Verify we’re within the utility easement before digging.; The easement grants 24/7 access for maintenance.; Record the permanent easement prior to final acceptance.
Encroachment Permit
Authorization from a jurisdiction to perform work within public right-of-way or to place facilities within it.
Obtain the city encroachment permit before lane closures.; Permit requires a stamped traffic control plan.; Coordinate inspections per the encroachment permit conditions.
Excavation Tolerance Zone
The area on either side of a marked utility where special care is required (often 18–24 inches each side); use hand tools or vacuum excavation.
Only soft-dig within the tolerance zone.; Pothole to verify depth before crossing the gas line.; Maintain marks and measure offsets to the utility in the zone.
Force Main
A pressurized sewer pipeline that conveys wastewater from a pump station to a gravity system or treatment facility.
Conduct a pressure test on the new 8-inch force main.; Include ARVs at high points per the plans.; Coordinate shutdowns with operations before tie-in.
Frac-Out
Inadvertent return of drilling fluid to the surface or waterbody during HDD due to pressurization and ground fractures.
Implement the frac-out contingency plan near the wetland.; Have spill kits and containment booms on site.; Reduce pump rate if returns drop suddenly.
Geotechnical Report
A subsurface investigation summary with soil classifications, groundwater, lab results, and recommendations for trench support, bedding, and pavement sections.
Use the geotech report to set trench box limits.; Anticipate running sand at 8 feet per the borings.; Follow recommended pipe bedding for the native soils.
Grade/Invert
Grade is the longitudinal slope; invert is the inside bottom elevation of a pipe. Critical for gravity flow and capacity.
Set the pipe invert to 423.25 feet at MH-6.; Verify grade with a laser to maintain 0.5% slope.; Record inverts in the as-builts.
Ground Penetrating Radar (GPR)
A geophysical method using radar pulses to detect subsurface objects and stratigraphy; useful for non-metallic utilities and unknowns.
Scan the intersection with GPR before finalizing the bore path.; Use GPR to supplement 811 locates.; Mark anomalies for verification potholes.
Hot Tap
A connection to a pressurized main (water, gas) without shutting it down, using a tapping sleeve and valve with a drilling machine.
Schedule the 12x6 hot tap with the water utility.; Pressure-test the sleeve prior to tapping.; Provide a tapping plan and contingency shutdown.
Hydro Excavation
Non-destructive excavation using high-pressure water and vacuum to safely expose utilities or dig precise holes (also called vacuum excavation).
Hydro-expose the fiber line at each crossing.; Use hydrovac within the tolerance zone.; Daylight the gas service before saw-cutting.
Indemnification
A contract clause where one party agrees to protect another from specified claims or liabilities (subject to state anti-indemnity laws and insurance).
The owner seeks broad-form indemnity in the GC.; Align indemnification with XCU coverage.; Carve out negligence per statute.
Inflow and Infiltration (I/I)
Clean water entering sanitary sewers from surface inflow (downspouts, inflow sources) or groundwater infiltration (cracks, joints), which reduces capacity.
CCTV found infiltration at multiple joints.; Rehab laterals to reduce I/I in Basin 3.; Measure I/I impacts during wet-weather flow.
Lien Waiver
A document releasing a contractor’s or supplier’s right to file a mechanics lien for work or materials, typically tied to progress or final payment.
Submit conditional lien waivers with the pay app.; Collect subcontractor waivers before release of retention.; Final waiver is required at closeout.
Lift Station
A facility with pumps, wet well, and controls that conveys wastewater from low to high elevation into a force main.
Bypass the lift station during wet well rehab.; Coordinate SCADA integration for the new pumps.; Test floats and pump curves before commissioning.
Liquidated Damages
Pre-agreed daily monetary amounts assessed for finishing late when actual damages are difficult to quantify.
LDs are $2,500/day beyond substantial completion.; Update the CPM schedule to mitigate LD exposure.; Seek time relief via change order to avoid LDs.
Manhole
A below-grade access structure for sewer or storm systems, consisting of base/bench, barrel, steps, frame, and cover.
Cast inverts per the standard detail.; Set frame and cover to final grade after paving.; Perform vacuum testing on precast manholes.
Material Submittal
Documentation provided for engineer approval of products and materials (datasheets, certifications, samples), verifying conformance to specs.
Submit pipe, valves, and tracer wire cut sheets.; Provide mix design submittals for flowable fill.; Track approvals in the submittal log.
Microtunneling
Remote-controlled, guided pipe jacking with a microtunnel boring machine (MTBM); maintains face pressure for precise line/grade in difficult ground.
Use microtunneling for the 60-inch outfall under the freeway.; Settlement monitoring is required along the alignment.; Launch and reception shafts must be dewatered.
NPDES Permit
National Pollutant Discharge Elimination System authorization for stormwater discharges from construction sites; requires a SWPPP and inspections.
File the NOI and post the NPDES coverage on site.; Keep rain logs and BMP inspections per the permit.; Stabilize disturbed soil before demobilization.
Notice to Proceed (NTP)
Formal written authorization to begin contract work; typically starts contractual time and milestone obligations.
The schedule’s Day 1 is the NTP date.; No fieldwork until NTP and permits are in hand.; Mobilize within 10 days of NTP per specs.
Open Cut
Traditional trench excavation for installing or replacing utilities from the surface, typically with shoring or sloping as needed.
Use open-cut installation except at roadway crossings.; Maintain trench width limits per the detail.; Restore pavement per the city standard after backfill.
OSHA 29 CFR 1926 Subpart P (Excavations)
Federal safety standard governing excavation and trenching, including protective systems, soil classification, access/egress, and inspections.
Provide a protective system for all trenches over 5 feet.; Classify soil per Appendix A before sloping.; A competent person must inspect excavations daily.
Pipe Bursting
Trenchless replacement method that fractures an existing pipe and pulls in a new pipe of equal or larger diameter along the same alignment.
Burst the 6-inch clay sewer to 8-inch HDPE.; Set up upstream/downstream bypass pumping.; Verify lateral reconnections after bursting.
Plans and Specifications
The contract drawings (plans) and written requirements (specs) that define the design, materials, standards, and procedures for construction.
Follow the plans for alignment and the specs for materials.; Specs require 2-sack slurry backfill in the roadway.; Resolve discrepancies via RFI to the engineer.
Potholing
Physically exposing an existing utility to confirm its location and depth, typically by vacuum excavation; also called daylighting.
Pothole all marked crossings before trenching.; Record elevations of potholes for the as-builts.; Use soft-dig methods within the tolerance zone.
Quantity Takeoff
Measurement and calculation of material and work quantities from plans to prepare bids, track progress, and support pay estimates.
Do a takeoff on pipe, fittings, and appurtenances.; Reconcile takeoff quantities with field installed totals.; Use the takeoff to forecast procurement needs.
Reinforced Concrete Pipe (RCP)
Structural concrete pipe with steel reinforcement, commonly used for storm drains and some sanitary sewers.
Install Class III RCP with rubber-gasket joints.; Provide Type 2 bedding per the detail.; Check joint gaps before backfilling.
Request for Information (RFI)
A formal written question to clarify plans/specs or resolve conflicts, often with schedule and cost implications.
Submit an RFI on the conflicting invert callouts.; Reference the sheet number and detail in the RFI.; Track RFI response time due to schedule impacts.
Subsurface Utility Engineering (SUE)
Engineering process that manages utility risk using quality levels: QL-D (records), QL-C (survey marks), QL-B (locate), QL-A (pothole).
The designer requested SUE QL-B along the corridor.; Upgrade to QL-A where conflicts are likely.; Incorporate SUE results into the plan set.
Traffic Control Plan (TCP)
A plan showing temporary traffic control devices, detours, and phasing to protect workers and the public, typically complying with MUTCD and local standards.
Submit a stamped TCP for the encroachment permit.; Set up advance warning signs before lane closures.; Maintain pedestrian access per the TCP.
USA 811 Ticket
A notice number created by calling 811 or submitting online to request utility locating before digging; triggers utility owner marking obligations.
Open a new 811 ticket before moving to the next block.; Keep the ticket on site and note its expiration date.; Reference the ticket in the daily report and photos.
Valve Box
A vertical enclosure that provides access to an underground valve’s operating nut; typically adjustable to finished grade.
Raise the valve box after the overlay.; Ensure valve boxes are plumb and centered on the nut.; Show valve box locations on the as-builts.
Water Main
A primary distribution pipeline for potable water; includes appurtenances such as valves, hydrants, and services.
Pressure- and bacteriologically-test the new water main.; Maintain 10 feet horizontal separation from sewer.; Use tracer wire on non-metallic mains.
XCU Coverage
Insurance coverage for eXplosion, Collapse, and Underground hazards typically excluded from general liability policies; critical for utility work.
Verify XCU endorsements on subs’ GL policies.; Owner requires $2M GL with XCU for trenchless work.; Align contract indemnity with XCU coverage.
Y-Branch (Wye)
A pipe fitting that joins a lateral to a main at an acute angle (often 45°) to reduce turbulence and maintain flow.
Install 6-inch wyes for each sewer service.; Use a wye instead of a tee on the gravity main.; Confirm wye orientation with the stationing.
Zone of Influence
The area of soil affected by excavation loads and movement; used to evaluate impacts on adjacent utilities, structures, and shoring design.
Keep the trench box outside the manhole’s zone of influence.; Check if the gas main lies within the excavation’s zone.; Adjust shoring where the ZOI intersects the duct bank.
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