Definitions

Back-up

An overflow or accumulation of water caused by clogging or by a stoppage.

Overflow 
Report sanitary sewer overflows immediately!

Blockage

Any incident in which a sewer is partially or completely blocked, causing a backup, a service interruption, or an overflow. Also called stoppage.

Overflow 2 
Report sanitary sewer overflows immediately!

Cleanout

An opening (usually covered or capped) in a wastewater collection system used for inserting tools, rods, or snakes while cleaning a pipeline or clearing a stoppage.

Collapsed Pipe

A pipe that has one or more points in its length that have been crushed or partially crushed by exterior pressures or impacts.

Collection System

A network of pipes, manholes, cleanouts, traps, siphons, lift stations, and other structures used to collect all wastewater and wastewater-carried wastes of an area and transport them to a treatment plant. The collection system includes land, wastewater lines and appurtenances, pumping stations, and general property.

Easement

Legal right to use the property of others for a specific purpose. For example, a utility company may have a five-foot (1.5 m) easement along the property line of a home. This gives the utility the legal right to install and maintain a sewer line within the easement.

Easement 7 

Properly maintained wastewater easements allow access to manholes for
routine maintenance and emergency repairs. 

Gravity Flow

Water or wastewater flowing from a higher elevation to a lower elevation due to the force of gravity. The water does not flow due to energy provided by a pump. Wherever possible, wastewater collection systems are designed to use the force of gravity to carry waste liquids and solids.

Grease Trap

A receptacle designed to collect and retain grease and fatty substances usually found in kitchen wastes or similar wastes. It is installed in the drainage system between the kitchen or other point of production of the waste and the building wastewater collection line. Commonly used to control grease from restaurants.

SC4

Yuck! Avoid this with proper maintenance of your grease trap.

Grit

The heavy material present in wastewater such as sand, coffee grounds, eggshells, gravel, and cinders. Also called detritus.

High-Velocity Cleaner

A machine designed to remove grease and debris from the smaller-diameter sewer pipes with high-velocity jets of water. Also called a high-pressure cleaner, hydraulic cleaner, hydro jet, jet cleaner, or jet rodder.

Infiltration

The seepage of groundwater into a sewer system, including service connections. Seepage frequently occurs through defective or cracked pipes, pipe joints and connections, interceptor access risers and covers, or manhole walls.

Inflow

Water discharged into a sewer system and service connections from such sources as, but not limited to, roof leaders, cellars, yard and area drains, foundation drains, cooling water discharges, drains from springs and swampy areas, around manhole covers or through holes in the covers, cross-connections from storm and combined sewer systems, catch basins, stormwaters, surface runoff, street wash waters, or drainage. Inflow differs from infiltration in that it is a direct discharge into the sewer rather than a leak in the sewer itself.

Lateral Sewer

A sewer that discharges into a branch or other sewer and has no other common sewer tributary to it. Sometimes called a street sewer because it collects wastewater from individual homes.

Lift Station/Pump Station

A wastewater pumping station that lifts the wastewater to a higher elevation when continuing the sewer at reasonable slopes would involve excessive depths of trench. Also, an installation of pumps that raise wastewater from areas too low to drain into available sewers.

Manhole

An opening in a sewer provided for the purpose of permitting operators or equipment to enter or leave a sewer. Sometimes called an access hole or a maintenance hole.

Easement

Most manholes are in paved areas.

Sewer Gas

  1. Gas in collection lines (sewers) that results from the decomposition of organic matter in the wastewater. When testing for gases found in sewers, test for oxygen deficiency, oxygen enrichment, and also for explosive and toxic gases. 
  2. Any gas present in the wastewater collection system, even though it is from such sources as gas mains, gasoline, and cleaning fluid.

Sewer Main

A sewer pipe to which building laterals are connected. Also called a collection main.

Snake

A stiff but flexible cable that is inserted into sewers to clear stoppages; also known as a sewer cable.

Television Inspection

An inspection of the inside of a sewer pipe made by pulling a closed-circuit television camera through the pipe.

CCTV

Wastewater Maintenance Technician operating a camera by remote control
while monitoring live footage inside a City truck.

Upstream

The direction against the flow of water; or, toward or in the higher part of a sewer or collection system.

Wasteline Vent

Most plumbing codes require a vent pipe connection of adequate size and located downstream of a trap in a building wastewater system. This vent prevents the accumulation of gases or odors and is usually piped through the roof and out of doors.

Wastewater

A community's used water and water-carried solids (including used water from industrial processes) that flow to a treatment plant. Stormwater, surface water, and groundwater infiltration also may be included in the wastewater that enters a wastewater treatment plant. The term sewage usually refers to household wastes, but this word is being replaced by the term wastewater.

Wastewater Collection System

The pipe system for collecting and carrying water and water-carried wastes from domestic and industrial sources to a wastewater treatment plant.



Public Works Maintenance and Operations Center
18080 NE 76th Street
Redmond, WA  98052

Contact
425-556-2827
Monday - Thursday
7:00 AM - 4:30 PM

Friday
7:00 AM - 3:30 PM
 
Contact
425-556-2500
After Hours & Holidays

Report a Concern
(Non-Emergency)

wastewater@redmond.gov

Side Sewer Location 
Contact
425-556-2876