DE Water Operator key terms

The treatment step in which a chemical such as alum is rapidly mixed into raw water to neutralize the electrical charges on suspended particles so they can clump together and be removed.

Gentle, slow stirring of chemically treated water that encourages destabilized particles to collide and grow into larger, settleable clumps called floc.

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

Passing water through a bed of granular media such as sand or anthracite to trap remaining particles, including many pathogens, before disinfection.

Reversing or scouring flow through a filter bed to lift and flush out trapped solids, restoring the media's ability to remove particles from water.

A measure of how cloudy water is because of suspended particles; high readings can shield pathogens from disinfection and indicate treatment problems.

The standard unit for reporting turbidity, determined by measuring how much light scatters off particles suspended in a water sample at a defined angle.

Treating water with a chemical or physical agent to inactivate or kill disease-causing microorganisms, protecting public health before the water reaches consumers.

The product of disinfectant concentration multiplied by contact time, used to judge whether a given organism has received enough disinfection under specified conditions.

The amount of active chlorine remaining in water after treatment and travel through the system, indicating continuing protection against microbial contamination.

A bench-scale procedure using multiple stirred beakers to determine the best coagulant dose and mixing conditions for a given raw water quality.

The flow of water applied per unit area of filter surface, usually expressed in gallons per minute per square foot, which affects particle removal efficiency.

The network of pipes, pumps, storage tanks, valves, and meters that delivers treated water from the treatment plant to homes, businesses, and fire hydrants.

A large buried pipe that carries treated water through streets and neighborhoods and feeds smaller service lines to individual properties.

A defined area of a distribution system kept within a specific pressure range by pumps, tanks, or valves so that service remains adequate at all elevations.

A pressure surge caused by sudden changes in flow velocity, such as rapid valve closure, that can damage pipes and fittings and must be controlled.

Any actual or potential link between a potable water system and a source of nonpotable water or other substance that could contaminate the drinking water supply.

Devices or assemblies such as air gaps and reduced-pressure zone valves that stop water from flowing backward into the potable system because of backpressure or backsiphonage.

A public notice telling customers to boil tap water or use bottled water because the supply may be contaminated or treatment has been interrupted.

A federal rule that uses coliform bacteria testing and repeat sampling to judge whether a water system's treatment and distribution integrity are adequate.

The highest concentration of a regulated contaminant legally allowed in water delivered to consumers, based on health effects and treatment feasibility.

The health-based target level for a contaminant below which no known or expected adverse health effects occur, set without considering treatment cost or technology.

A required practice or procedure, rather than a numeric limit, that a water system must follow when measuring a contaminant level is not feasible or practical.

An annual report that community water systems must provide to customers, summarizing source water, detected contaminants, compliance status, and health information.

An evaluation of the land area and activities that may contaminate a public water supply's source, used to identify risks and guide protection efforts.

The land area that drains rain and snowmelt into a particular stream, river, lake, or reservoir used as a drinking water source.

Water from rivers, lakes, reservoirs, or streams that is open to the environment and generally requires more treatment than groundwater.

Water stored in and moving through pores and fractures in soil and rock beneath the surface, often accessed by wells and usually lower in turbidity.

Managing the area around a drinking water well to prevent contaminants from reaching the aquifer that supplies that well.

A space large enough to enter, with limited entry or exit, not designed for continuous occupancy, such as a wet well or vault, requiring special safety procedures.

A procedure for isolating and de-energizing equipment, then attaching locks and tags, so it cannot be started while workers service or repair it.

A toxic, flammable gas with a rotten-egg odor that can form in sewers and sludge areas and can deaden the sense of smell at dangerous concentrations.

Compounds such as trihalomethanes that form when disinfectants react with naturally occurring organic matter, requiring monitoring and control under drinking water rules.

A measure of organic material in water that can react with disinfectants to form byproducts and can interfere with coagulation and filtration.

Maintaining required logs, monitoring results, and reports for the periods specified by regulation, so compliance and operational history can be verified during inspections.

A state-issued credential showing that a water system operator has met education, experience, and examination requirements for a given classification level.