Sewer Services Industry Terminology

As-built drawings

Final record drawings that document the exact locations, elevations, materials, and field changes of installed sewer assets. Used for operations, maintenance, and future design planning.

Submit as-builts within 30 days of substantial completion | The GIS was updated using as-built data | As-builts show the lateral was relocated

Asset management

A systematic approach to managing infrastructure over its lifecycle by integrating inventory, condition, risk, levels of service, and funding strategies (often aligned with ISO 55000).

We prioritized rehab using risk-based asset management | The CMMS feeds the asset management plan | Council approved the asset management policy

Backflow prevention

Devices or design features (e.g., backwater valves, air gaps) that prevent reverse flow from a sewer into buildings or potable systems during surcharges.

Install backwater valves on basement connections | Test the backflow preventer annually | The surcharge highlighted need for backflow prevention

Bypass pumping

Temporary conveyance of sewage around a work area to maintain service during inspection, cleaning, repair, or rehabilitation.

Set up a 12-inch bypass for the CIPP cure | The utility approved the bypass plan | Nighttime bypass reduced customer impacts

Call Before You Dig (811)

The one-call utility notification service that coordinates locating and marking of underground utilities prior to excavation.

We called 811 two days before potholing | 811 tickets must be closed before mobilization | No excavation begins without 811 clearance

CCTV inspection

Closed-circuit television inspection using a crawler or push camera to document internal pipe condition and defects (often coded per NASSCO PACP).

Schedule PACP-coded CCTV of the 12-inch main | CCTV revealed root intrusion | Post-lining CCTV confirms service reinstatements

Change order

A formal modification to contract scope, price, and/or time, approved by the owner under the contract terms.

A change order covered additional laterals | Weather delays led to a time-only change order | The engineer rejected the unsupported change order

CIPP (Cured-in-Place Pipe)

A trenchless rehabilitation method where a resin-impregnated liner is inserted into an existing pipe and cured (steam, hot water, or UV) to form a new pipe within the old.

UV-CIPP reduced cure time and traffic impacts | We selected epoxy resin for the liner | CIPP was installed from MH-12 to MH-18

CMMS (Computerized Maintenance Management System)

Software used to plan, schedule, track, and document maintenance activities, work orders, assets, and inventory.

Jetting routes are generated by the CMMS | Integrate CMMS with GIS for asset IDs | CMMS data supports KPI reporting

CMOM (Capacity, Management, Operation, and Maintenance)

An EPA framework for improving collection system performance through documented policies, staffing, training, preventive O&M, and capacity assurance.

The consent decree mandates a CMOM program | The CMOM audit found gaps in training | Our CMOM plan targets I/I reduction

Confined Space Entry (CSE)

A safety program governing entry into spaces like manholes and wet wells with hazards such as toxic gases, engulfment, or limited egress.

A CSE permit was posted at MH-44 | Continuous gas monitoring during entry | The attendant maintained CSE logs

Cross connection

Any improper physical link allowing unintended flow between systems (e.g., storm to sanitary, potable to non-potable), causing contamination or I/I.

Smoke testing identified a storm-to-sanitary cross connection | Eliminate cross connections to reduce I/I | Ordinance prohibits sump pump cross connections

Deflection testing (mandrel)

Verification that flexible pipes (e.g., PVC/HDPE) have not deformed beyond allowable limits by pulling a rigid mandrel through the pipe.

A 7.5 percent mandrel passed all segments | Perform deflection tests after backfill settlement | Spec calls for both mandrel and CCTV

Dewatering

Lowering groundwater or removing water from an excavation to create safe, stable working conditions or reduce inflow to the work area.

Wellpoints were used for dewatering | Discharge was covered under an NPDES permit | Dewatering enabled manhole rehab in high groundwater

Easement access

Legal right-of-way and practical means to reach sewer facilities located on private property or off-road corridors.

Easement clearing improved off-road access | Verify easement rights before mobilizing | A tracked jetter was used for easement access

EPA Consent Decree

A legally binding agreement with EPA/DOJ under the Clean Water Act requiring specific improvements, schedules, and reporting for sewer system compliance.

SSO reductions are milestones in the decree | Annual CMOM reporting is required | Penalties apply for missed deadlines

Exfiltration

Leakage of wastewater out of a sewer through cracks, joints, or defects, causing environmental contamination and loss of flow.

Air testing indicated exfiltration | Lining eliminated exfiltration points | Low groundwater odors suggested exfiltration

Flow monitoring

Measuring sewer flows at strategic points (temporary or permanent) to quantify capacity, diurnal patterns, and I/I during dry and wet weather.

Installed area-velocity meters before storm season | Data informed hydraulic model calibration | Monitoring captured peak wet-weather flow

FOG (Fats, Oils, and Grease)

Substances from kitchens and industry that congeal in sewers, leading to blockages, odors, and SSOs if unmanaged.

FOG control program includes grease trap inspections | Hot spots noted near restaurants | Bioenzymes were dosed to reduce FOG buildup

Force main

A pressurized pipeline that conveys sewage from a pump station to a gravity sewer or treatment plant.

The lift station discharges to a 12-inch force main | Surge control protects the force main | The force main tie-in requires a shutdown

GIS (Geographic Information System)

Spatial database and mapping tools used to inventory sewer assets, visualize conditions, and integrate with CMMS and modeling.

Updated GIS with as-built lateral locations | Field crews use GIS on tablets | GIS layers show pipe age and material

Grade (slope)

The longitudinal slope of a pipe, usually expressed as percent fall, that influences velocity and capacity per Manning’s equation.

Insufficient grade caused sedimentation | Design grade set at 0.40 percent | CIPP reduced diameter but not grade

Gravity sewer

A pipeline that conveys sewage by gravity flow rather than pressure, relying on slope and hydraulic grade line.

An 8-inch PVC gravity sewer runs in the alley | Wet-weather surcharging occurred in the gravity line | Gravity alignment avoided a deep trench

H2S (Hydrogen Sulfide)

A toxic, corrosive sewer gas that causes odor complaints and concrete/metal corrosion; requires monitoring and ventilation for safety.

H2S readings exceeded 10 ppm in the manhole | RCP corrosion was caused by H2S attack | Nitrate addition mitigated H2S formation

Hydro jetting

High-pressure water cleaning of sewers to remove debris, roots, FOG, and scale; often done with a jet/vac combo unit.

Hydro jetting preceded CCTV inspection | A warthog nozzle removed heavy scale | Set pressure at 2,000 psi for the 6-inch line

I/I (Inflow and Infiltration)

Unwanted stormwater entering the sanitary system: inflow via direct connections (e.g., roof drains) and infiltration via defects and joints.

I/I reduction target is 30 percent | Smoke and dye testing identified I/I sources | CIPP and manhole coatings reduce I/I

Invert elevation

The internal bottom elevation of a pipe or manhole channel, used to establish hydraulic grade and alignment.

Verify invert before setting the bypass | Design invert ties into the existing manhole channel | Misstated inverts caused back pitch

Inverted siphon

A depressed sewer crossing (often under obstacles) that runs full under pressure; requires special maintenance to avoid solids buildup.

A two-barrel siphon crosses under the creek | Schedule regular flushing to prevent deposition | Bypass was needed to rehab the siphon

Jet/Vac truck (Combination unit)

A truck combining high-pressure water jetting with a vacuum system to clean sewers and remove debris.

The combo unit cleaned 1,000 ft per day | Decant at an approved disposal site | Vacuumed grit from the manhole bench

Job Safety Analysis (JSA)

A task-level risk assessment that identifies hazards and defines controls before starting the work.

The crew completed the JSA before entry | JSA highlighted required LOTO steps | Supervisors review JSAs daily

KPI (Key Performance Indicator)

A quantifiable metric used to evaluate operational performance and service levels (e.g., cleaning productivity, SSO rate).

KPI: miles of sewer cleaned per month | SSO frequency is a KPI we track | Response time KPI improved after CMMS rollout

LACP (Lateral Assessment Certification Program)

NASSCO’s standard and certification for inspecting and coding the condition of service laterals.

Contractor must provide LACP videos | LACP codes lateral defects consistently | Used LACP results to plan lateral renewals

Lateral sewer

A pipe that connects a building or property to the public main (ownership limits vary by jurisdiction).

Locate lateral taps before lining | Root intrusion common in clay laterals | City maintains laterals to the property line

Lift station

A pump station that raises sewage to a higher elevation or into a force main when gravity flow is not feasible.

The wet well at Elm lift station was rehabilitated | SCADA alarms originated at Lift Station 7 | Redundant pumps are sized for peak flow

Lockout/Tagout (LOTO)

Procedures to isolate and de-energize equipment (electrical, mechanical, pneumatic) to protect workers during maintenance.

Apply LOTO on the pump MCC before service | LOTO logs are audited weekly | Use hasps for group LOTO

MACP (Manhole Assessment Certification Program)

NASSCO’s standard and certification for consistent manhole inspection, defect coding, and condition grading.

MACP Level 2 is required by spec | MACP found severe chimney leaks | Rehab was prioritized using MACP ratings

Manhole

An access structure to the sewer system containing frame, cover, chimney, cone, barrel, bench, and channel.

Replace the manhole frame and cover | A drop manhole addresses the 12-ft elevation difference | Leaking rings were sealed to stop I/I

Manning’s n

A roughness coefficient in Manning’s equation that represents frictional resistance; varies by pipe material and condition.

Used n=0.013 for PVC in the model | Deposits increased the effective n | Capacity is sensitive to assumed n values

NASSCO

The National Association of Sewer Service Companies, which sets industry standards and training for PACP, MACP, and LACP.

Require NASSCO-certified CCTV operators | PACP is a NASSCO program | Staff will attend NASSCO training next quarter

Notice to Proceed (NTP)

Formal written authorization from the owner to the contractor to begin work under the contract.

NTP was issued on May 1 | The submittal clock starts at NTP | Mobilization is required within 10 days of NTP

NPDES permit

A Clean Water Act permit regulating discharges to waters of the U.S., applicable to CSO/SSO events and construction dewatering.

Bypass discharge is covered by our NPDES permit | The consent decree ties to NPDES compliance | Dewatering requires NPDES notification

O&M (Operations and Maintenance)

Activities and procedures to operate, inspect, clean, repair, and manage sewer system assets on a routine basis.

The O&M budget funds CCTV and jetting | The contractor submitted the O&M manual | Preventive O&M reduces SSOs

Open-cut excavation

Traditional construction method involving trenching from the surface to install, replace, or repair buried sewers.

Open-cut was selected where utilities were sparse | A trench box is required for open-cut | Open-cut is the alternative to trenchless here

OSHA Trenching and Excavation Standard

U.S. safety regulations (29 CFR 1926 Subpart P) governing excavation safety, including sloping, shoring, shielding, and inspections.

Soil was classified Type C per OSHA | The competent person inspected the trench | Follow OSHA benching and shoring limits

PACP (Pipeline Assessment Certification Program)

NASSCO’s standardized method and certification for coding, rating, and reporting pipeline defects from CCTV.

Submit PACP databases and videos with reports | PACP ratings drove the rehab plan | The inspector holds PACP certification

Pipe bursting

A trenchless method that fractures the existing pipe while simultaneously pulling in a new pipe, often allowing upsizing.

We upsized from 8-inch to 12-inch by pipe bursting | Pre-burst CCTV located all services | Static bursting was chosen over pneumatic

PPE (Personal Protective Equipment)

Equipment worn to minimize exposure to hazards, such as helmets, eye protection, respirators, gas monitors, gloves, and high-visibility apparel.

CSE requires multi-gas meters as PPE | Crews used chemical-resistant gloves | Replace PPE per manufacturer schedule

SCADA (Supervisory Control and Data Acquisition)

Telemetry and control systems that monitor and operate lift stations, flow meters, and other remote assets in real time.

SCADA trends showed pump short-cycling | Alarms from Lift Station 7 were acknowledged in SCADA | SCADA integrates with the CMMS

Smoke testing

A method that blows non-toxic smoke into sewers to identify inflow sources and cross connections by observing where smoke exits.

Smoke testing found a roof drain tied to sanitary | We smoked the basin after a rain event | Notices were sent to residents before smoke testing

SSO (Sanitary Sewer Overflow)

A discharge of untreated sewage from the collection system to the environment due to blockages, capacity limits, equipment failures, or storms.

The SSO report was filed within 24 hours | FOG caused last quarter's SSO | Our KPI targets SSO reductions each year