CO Water Operator key terms

A water treatment step where a chemical such as alum is rapidly mixed into raw water to neutralize particle charges so small suspended solids can stick together.

Gentle stirring of coagulated water that encourages small particles to collide and form larger, settleable clumps called floc before settling.

A treatment process where water sits in a basin long enough for heavier suspended solids and floc to settle to the bottom as sludge.

Passing water through a bed of sand, anthracite, or other media to trap remaining particles after clarification and before disinfection.

Killing or inactivating disease-causing organisms in water using chlorine, UV light, ozone, or other methods; it is typically the final barrier before treated water enters the distribution system.

A disinfection measure that multiplies disinfectant concentration (C) by contact time (T); higher values indicate more microorganism inactivation.

Cloudiness in water caused by suspended particles that scatter light; it is measured in nephelometric turbidity units and can shield pathogens from disinfection.

A bench-scale procedure using several beakers to compare coagulant doses and mixing conditions and choose the best treatment settings.

Reversing flow through a filter bed to lift and wash away trapped particles, restoring the filter's ability to remove solids.

The chlorine remaining in treated water after a set contact time; it protects water from contamination as it travels through the distribution system.

Any actual or potential link between a potable water system and a source of contamination or nonpotable water that could allow backflow.

A device installed to stop reverse flow of water that could carry contaminants into a potable water system or plumbing.

A pressure surge caused by a sudden change in water velocity, such as rapid valve closure, which can damage pipes and fittings.

A pumping facility that increases water pressure in a distribution system, often to serve higher elevations or distant areas.

A tank raised on a tower that uses gravity to maintain pressure and provide water storage in a distribution system.

A defined area of a distribution system where water pressure is kept within a similar range using pumps, tanks, and pressure-reducing valves.

A valved connection on a water main that lets firefighters draw water and that can be used for flushing and flow testing.

A large pipe in a distribution system that carries water from treatment plants, pumps, or storage to smaller service lines.

Opening hydrants or blowoffs to send water through mains at high velocity to remove sediment and stale water.

The pipe that carries water from a distribution main to a customer's property or building. It usually includes a meter and a customer shutoff valve.

The wastewater that enters a treatment plant or a specific treatment unit before any treatment has been applied to it.

The treated water that leaves a wastewater treatment plant or treatment process and is discharged or reused, often to the environment.

The first major wastewater treatment stage, where screening, grit removal, and settling remove large solids and some suspended material.

A secondary treatment process in which aeration mixes wastewater with microorganism-rich sludge that consumes organic matter and forms settleable solids.

A tank where air or oxygen is supplied to wastewater so microorganisms can break down organic matter and keep solids mixed.

The concentration of suspended solids, including bacteria and other microorganisms, in the aerated mixed liquor of an activated sludge basin.

Settled sludge from a secondary clarifier that is pumped back to the aeration basin to maintain a healthy population of microorganisms.

A calculated number that indicates how well activated sludge settles; it is the volume occupied by one gram of settled solids after 30 minutes.

A process that breaks down organic solids in a sealed, oxygen-free tank, producing biogas and reducing the volume of sludge.

Treated wastewater sludge that meets regulatory standards and can be land-applied or otherwise beneficially used; treatment reduces pathogens and vector attraction.

A pipe system that collects domestic, commercial, and industrial wastewater and carries it to a treatment plant, excluding stormwater.

A single pipe system that carries both sanitary wastewater and stormwater runoff to a treatment plant or overflow point.

Groundwater that seeps into sewers (infiltration) plus stormwater that enters through such routes as manholes or roof drains (inflow).

An opening in a sewer line with a removable cover that provides access for inspection, cleaning, and repair.

A facility with pumps that raise wastewater to a higher elevation so it can continue flowing by gravity.

A pressurized sewer pipe that carries wastewater pumped from a lift station rather than flowing by gravity.

A sewer pipe laid on a slope so wastewater flows downhill without pumping; it is the most common type in collection systems.

The pipe that carries wastewater from a single building or property to the public sewer main; it is often maintained by the property owner.

The inside bottom surface of a sewer pipe or manhole, often measured to determine pipe elevation and flow slope.

An enclosed or partially enclosed area with limited entry and exit that may contain hazardous air or engulfment hazards, requiring special safety procedures.